ISSN 1346-7301
NILIM Research Report No.52
January 2013

Research Report of the National Institute for Land and Infrastructure Management

No.52

January 2013

Initiatives by the National Institute for Land and Infrastructure Management in
Response to the 2011 Great East Japan Earthquake－Records of Activities Concerning Emergency Responses and Engineering
Contributions－

Emergency Responses and Engineering Contributions by NILIM
for the Recovery from the 2011 Great East Japan Earthquake

National Institute for Land and Infrastructure Management
Ministry of Land, Infrastructure, Transport and Tourism, Japan

Foreword
The earthquake off the Pacific coast of Tohoku occurred at 14:46 on March 11, 2011, with the
hypocenter located off the Sanriku coast. Estimated to have been approximately 500km long and
200km wide, with the largest slip measuring more than 30m, the focal region of this earthquake
extended from the waters off the coast of Iwate Prefecture to those off the coast of Ibaraki
Prefecture. It was a megaquake with a magnitude of 9.0, in which multiple focal regions in theJapan Trench became synchronized. As well as strong tremors being observed over an
extensive area, a massive tsunami with a wave height of more than 10m and a maximum runup
height of 40m caused immense damage.
The number of dead and missing persons as a result of the Great East Japan Earthquake hasreached 18,579 (as of January 16, 2013; survey by the National Police Agency). This was thefirst natural disaster since World War II in which the total number of dead and missing exceeded
10,000. Moreover, tremendous damage has been caused to buildings and public facilities
including coastlines, harbors, airports, sewerage systems, rivers, and roads, mainly on the
Pacific coast of the Tohoku and Kanto regions. The cost of damage to social infrastructure andother facilities is estimated to be approximately 17 trillion yen (Cabinet Office, disastermanagement section). As well as expressing our deepest condolences to the families of those
who lost their lives in this catastrophe, we at NILIM would also like to convey our heartfelt
sympathies to all those affected by the disaster in other ways.
As befits its role as a research institute affiliated to the Ministry of Land, Infrastructure,
Transport and Tourism, the National Institute for Land and Infrastructure Management has
implemented various endeavors to date, working in partnership with the Public Works ResearchInstitute, the Building Research Institute, and the Port and Airport Research Institute, anddispatching a cumulative total of 592 staff members to the area as part of the Technical
Emergency Control Forces (TEC-FORCE) and other bodies, starting in the immediate aftermathof the earthquake.
This report has been prepared as a record of the emergency response and technical support
implemented by this institute after the disaster. More specifically, the main content includes
emergency damage studies and damage analysis focused on facilities within NILIM’s jurisdiction;
details of emergency measures, and deliberations and proposals aimed at recovery andreconstruction; technical support provided on the ground, to such bodies as the Regional
Development Bureaus and local authorities; technical support provided in relation to legislationand the revision of technical standards that became necessary as an emergency; and initiatives
related to new challenges that surfaced in the aftermath of the disaster. The intention in
publishing this report is to provide a permanent record of the measures that NILIM has taken todate in response to the disaster, in order to learn lessons from this disaster and be prepared for
future disasters, thereby further improving its ability as a research institute to respond todisasters from the outset.
So far, in parallel with its emergency response and technical support measures and with theaim of contributing to the development of disaster-resistant facilities in light of its experiences ofthis earthquake, NILIM has conducted surveys, analysis, and research, such as detailed fieldsurveys, including subsurface exploration, as well as verification studies of factors contributing todamage and effective measures, based on model experiments and analyses. The results ofthese endeavors have already been published as disaster study bulletins or research reports.

However, many challenges remain, so NILIM continues diligently to conduct such surveys,
analysis, and research concerning this disaster.
For example, in order to respond to the highest class of tsunami (Level 2 tsunami) based on a
combination of hard and soft measures, it is necessary to implement hard measures such as
developing robust coastal protection facilities and facilities that apply the principles ofdefense-in-depth, as well as soft measures focused on evacuation, such as developing hazard
maps. However, there is a mountain of issues to be resolved in order to actually apply thesemeasures in the field and achieve steady results, so research in these areas is ongoing. In
addition, studies are also being carried out concerning topics including measures to deal withlong-period ground motion in high-rise buildings and measures to deal with liquefaction, andNILIM will publish in due course any new results that it obtains from its surveys, analysis, andresearch.
With a megaquake in the Nankai Trough and an earthquake directly under Tokyo both forecast,contingency planning against an earthquake disaster is an extremely pressing issue, so NILIM
must learn as many lessons as possible from this recent major earthquake and make effective
use of them in future. NILIM intends to make adequate preparations for a disaster, in order toassist those on the ground.
January 2013
Shuhei Kazusa
Director-General
National Institute for Land and Infrastructure Management
Ministry of Land, Infrastructure, Transport and Tourism

Contents
Foreword
1. Introduction ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

1

2. The Great East Japan Earthquake and Responses to This by the National Government, MLIT,
and NILIM ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

3

2.1 Overview of the Earthquake and Resultant Damage ・・・・・・・・・・・・・・・・・

3

2.2 Response by the National Government ・・・・・・・・・・・・・・・・・・・・・・・

24

2.3 Response by the Ministry of Land, Infrastructure, Transport and Tourism ・・・・・・・・

26

2.4 Response by the National Institute for Land and Infrastructure Management ・・・・・・・

29

2.5 Other Relevant Developments ・・・・・・・・・・・・・・・・・・・・・・・・・・・

52

3. Initiatives Focused on Recovery and Reconstruction Following the Great East Japan
Earthquake ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

56

3.1 Initiatives by the National Institute for Land and Infrastructure Management Focused on
Recovery and Reconstruction ・・・・・・・・・・・・・・・・・・・・・・・・・・・

56

3.2 Evaluation and Analysis of Seismic Force and Action ・・・・・・・・・・・・・・・・・

57

3.2.1 Ground Motion ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

57

3.2.1.1. Characteristics of the observed ground motions ・・・・・・・・・・・・・・

58

3.2.1.2. Research on Design Earthquake Motion for an Interplate Earthquake ・・・・・

59

3.2.2 Tsunami ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

64

3.2.2.1 Coastline ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

64

3.2.2.2 Ports ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

87

3.2.2.3 Rivers ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

91

3.2.3 Soil Liquefaction ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 100
3.3 Technical Support for Restoration/Reconstruction Measures ・・・・・・・・・・・・・ 104
3.3.1 Sediment Disasters ・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 104
3.3.1.1 Overview of sediment disasters ・・・・・・・・・・・・・・・・・・・・・ 104
3.3.1.2 On-site Surveys of and Local Responses to Sediment Disasters ・・・・・・・ 106
3.3.1.3 Survey of Large-scale Collapses Using Optical Satellite Images ・・・・・・・ 116
3.3.1.4 Assessing Danger of Slope Failures through Earthquakes ・・・・・・・・・・ 120
3.3.2 Sewage ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 125
3.3.3 River ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 145
3.3.4 Water Resources ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 155
3.3.5 Shore and Coast ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 171
3.3.6 Roads ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 190
3.3.7 Ports and Harbors (including coastal protection facilities in ports) ・・・・・・・・・ 206
3.3.7.1 Port Facilities ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 206
3.3.7.2 Coastal protection facilities in ports ・・・・・・・・・・・・・・・・・・・・ 218
3.3.8 Airport ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 222
3.3.9 Building ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 227
3.3.9.1 Damages Survey, Field Support ・・・・・・・・・・・・・・・・・・・・・ 227
3.3.9.2 Damage to buildings from earthquakes ・・・・・・・・・・・・・・・・・・ 228i

3.3.9.3 Damage to buildings by tsunami ・・・・・・・・・・・・・・・・・・・・・ 236
3.3.9.4 Damage to buildings from fire ・・・・・・・・・・・・・・・・・・・・・・ 243
3.3.9.5 Response based on Building Damage ・・・・・・・・・・・・・・・・・・ 244
3.3.10 Housing ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 255
3.3.11 Cities and Towns ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 264
3.3.11.1 Damage situation of built up areas ・・・・・・・・・・・・・・・・・・・ 264
3.3.11.2 Correspondence to the restoration and the revival of suffering community
areas ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 266
3.3.11.3 Action of residential land anti soil liquefaction measures in the damaged built
up areas ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 268
3.3.12 Parks and Green Spaces ・・・・・・・・・・・・・・・・・・・・・・・・・ 272
3.3.13 Disaster Management ・・・・・・・・・・・・・・・・・・・・・・・・・・・ 282
3.3.14. Information Field ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 288
3.3.14.1 Provision of information during Disaster or Recovery ・・・・・・・・・・・ 288
3.3.14.2 Correction of coordinates of road ground control points and fundamental
geospatial data of roads ・・・・・・・・・・・・・・・・・・・・・・・・ 296
3.3.15 Coastal Environment ・・・・・・・・・・・・・・・・・・・・・・・・・・・ 300
3.3.16 River Environment ・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 308
3.4 Research Study ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 314
3.4.1 Orientation of Research Activity for the Future Recovery ・・・・・・・・・・・・ 314
3.4.2 Research on Multiple Defense Systems and Tsunami Disaster Mitigation ・・・・・ 316
3.4.3 Research on technologies for disaster reduction planning in coastal cities
・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 324
3.4.4 Research on Risk and Crisis Management Strategy for Excessive and Multiple
Actions of Natural Disasters ・・・・・・・・・・・・・・・・・・・・・・・・・ 325
3.4.5 Research and Development in Information and Technology Area ・・・・・・・・・ 328
3.4.5.1 Research on the platform development for collecting and analyzing movementof people・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 328
3.4.5.2 Research on supportive use of 3D CAD data for disaster rehabilitation
processes ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 332
3.4.5.3 Research on the management method of buried debris using computer aided
construction technology ・・・・・・・・・・・・・・・・・・・・・・・・・ 338
3.4.5.4 Research on Bridge Monitoring Technology using 3D CAD Design Data ・・・・ 341
4. Lessons learned and Future Tasks Concerning Disaster Countermeasures
and Risk Management・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 344
Afterword ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 349
Reference Material Teams Sent to Sites by TEC-FORCE, etc. ・・・・・・・・・・・・・・・ 350
List of Reference Web Site Addresses ・・・・・・・・・・・・・・・・・ 355

ii

List of Authors
1. Introduction
Hiroyuki KISHIDA, Dr.Eng, Executive Director for Research Affairs
2. The Great East Japan Earthquake and Responses to This by the National Government, MLIT, and NILIM
2.1 Overview of the Earthquake and Resultant Damage
Shigeki UNJOH, Dr.Eng, Research Coordinator for Earthquake Disaster Prevention, ResearchCenter for Disaster Management
2.2 Response by the National Government
Hiroshi TANNO, Coordinator for Research Planning, Planning and Research Administration
Department
2.3 Response by the Ministry of Land, Infrastructure, Transport and Tourism
Hiroshi TANNO, Coordinator for Research Planning, Planning and Research Administration
Department
2.4 Response by the National Institute for Land and Infrastructure Management
Hiroshi TANNO, Coordinator for Research Planning, Planning and Research Administration
Department
Naokazu TAKADA, Research Coordinator for Coastal and Marine Disaster Prevention, Coastal,Marine and Disaster Prevention Department
Shigeki UNJOH, Dr.Eng, Research Coordinator for Earthquake Disaster Prevention, ResearchCenter for Disaster Management
Akio MIZUTANI, Director, Housing Department(The former Research Coordinator for Disaster Mitigation of Building, Research Center for
Disaster Management)
2.5 Other Relevant Developments
Hiroshi TANNO, Coordinator for Research Planning, Planning and Research Administration
Department
3. Initiatives Focused on Recovery and Reconstruction Following the Great East Japan Earthquake
3.2 Evaluation and Analysis of Seismic Force and Action
3.2.1. Ground Motion
Shigeki UNJOH, Dr.Eng, Research Coordinator for Earthquake Disaster Prevention, ResearchCenter for Disaster Management
Masahiro KANEKO, Head of Earthquake Disaster Prevention Division, Research Center for
Disaster Management
Shojiro KATAOKA, Dr.Eng, Senior Researcher of Earthquake Disaster Prevention Division,
Research Center for Disaster Management
Kazuhiro NAGAYA, Senior Researcher of Earthquake Disaster Prevention Division, ResearchCenter for Disaster Management
Kazunari MATSUOKA, Researcher of Earthquake Disaster Prevention Division, ResearchCenter for Disaster Management
3.2.2 Tsunami
3.2.2.1 Coastline
Yoshio SUWA, Head of Coast Division, River Departmentiii

Fuminori KATO, Senior Researcher of Coast Division, River Department
Satoshi HATOGAI, Researcher of Coast Division, River Department
Kunihiro WATANABE, D.Agr., Researcher of Coast Division, River Department
3.2.2.2 Ports
Tadashi ASAI, Research Coordinator for Coastal and Marine Affairs, Coastal, Marine andDisaster Prevention Department
3.2.2.3 Rivers
Atsushi HATTORI, Dr.Eng, Head of River Division, River Department
Masaki FUKUSHIMA, Dr.Eng, Senior Researcher of River Division, River Department
3.2.3 Soil Liquefaction
Shigeki UNJOH, Dr.Eng, Research Coordinator for Earthquake Disaster Prevention, ResearchCenter for Disaster Management
Masahiro KANEKO, Head of Earthquake Disaster Prevention Division, Research Center for
Disaster Management
Shojiro KATAOKA, Dr.Eng, Senior Researcher of Earthquake Disaster Prevention Division,
Research Center for Disaster Management
Kazuhiro NAGAYA, Senior Researcher of Earthquake Disaster Prevention Division, ResearchCenter for Disaster Management
Kazunari MATSUOKA, Researcher of Earthquake Disaster Prevention Division, ResearchCenter for Disaster Management
3.3 Technical Support for Restoration/Reconstruction Measures
3.3.1 Sediment Disasters
Masato NISHI, Director of Tone River System Sabo Work Office, Kanto Regional Development
Bureau(The former Research Coordinator for Sediment-related Disaster Prevention, Research Center
for Disaster Management)
Nobutomo OSANAI, D.Agr., Director of Erosion and Sediment Control Research Group, Public
Works Research Institute(The former Head of Erosion and Sediment Control Division, Research Center for Disaster
Management)
Atsushi OKAMOTO, Head of Erosion and Sediment Control Division, Research Center for
Disaster Management
Yoko TOMITA, Director of Jinzu Sabo Work Office, Hokuriku Regional Development Bureau(The former Senior Researcher of Erosion and Sediment Control Division, Research Center for
Disaster Management)
Masaki MIZUNO, Senior Researcher of Erosion and Sediment Control Division, ResearchCenter for Disaster Management
Taro UCHIDA, D.Agr., Senior Researcher of Erosion and Sediment Control Division, ResearchCenter for Disaster Management
Yasuhiro NOMURA, Researcher of Erosion and Sediment Control Division, Research Center
for Disaster Management
Shin'ichiro HAYASHI, Researcher of Erosion and Sediment Control Division, Research Center
for Disaster Managementiv

Shinya KATSURA, Chief of Sabo (Erosion and Sediment Control) Planning Division, Sabo
(Erosion and Sediment Control) Department, Water and Disaster Management Bureau(The former Researcher of Erosion and Sediment Control Division, Research Center for
Disaster Management)
Takumi SATO, Visiting Researcher of Erosion and Sediment Control Division, Research Center
for Disaster Management
3.3.2 Sewage
Toshihiro YOKOTA, Head of Wastewater System Division, Water Quality Control Department
Wataru FUKATANI, Senior Researcher of Wastewater System Division, Water Quality Control
Department
Manabu MATSUHASHI, Researcher of Wastewater System Division, Water Quality Control
Department
Hiromasa YAMASHITA, Senior Researcher of Wastewater and Sludge Management Division,
Water Quality Control Department
3.3.3 River
Atsushi HATTORI, Dr.Eng, Head of River Division, River Department
Masaki FUKUSHIMA, Dr.Eng, Senior Researcher of River Division, River Department
3.3.4 Water Resources
Masaki KAWASAKI, Head of Water Management and Dam Division, River Department
Takeshi ITO, Researcher of Water Management and Dam Division, River Department
3.3.5 Shore and Coast
Yoshio SUWA, Head of Coast Division, River Department
Fuminori KATO, Senior Researcher of Coast Division, River Department
Satoshi HATOGAI, Researcher of Coast Division, River Department
Kunihiro WATANABE, D.Agr., Researcher of Coast Division, River Department
3.3.6 Roads
Takashi TAMAKOSHI, Head of Bridge and Structures Division, Road Department
Masanori OOKUBO, Senior Researcher of Bridge and Structures Division, Road Department
Takenobu KITAMURA, Researcher of Bridge and Structures Division, Road Department
Yoshiteru YOKOI, Researcher of Bridge and Structures Division, Road Department
3.3.7 Ports and Harbors
Tsuyoshi NAGAO, Dr.Eng, Director, Port and Harbor Department
Tadashi ASAI, Research Coordinator for Coastal and Marine Affairs, Coastal, Marine andDisaster Prevention Department
3.3.8 Airport
Yukitomo TSUBOKAWA, Dr.Eng, Senior Researcher of Airport Facilities Division, Airport
Department
Junichi MIZUKAMI, Tokyo International Airport, Kanto Regional Development Bureau(The former Head of Airport Facilities Division, Airport Department)
3.3.9 Building
Hiroyuki TANANO, Dr.Eng, Research Coordinator for Quality Control of Building, Building
Department
Atsuo FUKAI, Head of Standards and Accreditation System Division, Building Department
Namihiko INOUE, Senior Researcher of Standards and Accreditation System Division, Buildingv

Department
Yoshihiro IWATA, Dr.Eng, Senior Researcher of Standards and Accreditation System Division,
Building Department
Toshikazu KABEYASAWA, Dr.Eng, Researcher of Standards and Accreditation System Division,
Building Department
Yoshihiro YOKOTA, Researcher of Standards and Accreditation System Division, Building
Department
Tomohiro NARUSE, Dr.Eng, Head of Fire Standards Division, Building Department
3.3.10 Housing
Kiyohiro SHIRAI, Director, Department of Research Planning and Management, Building
Research Institute(The former Director, Housing Department)
Masashi MORI, Director of Housing Planning Division, Housing Department
Hiroshi HASEGAWA, Dr.Eng, Head of Residential Environment Planning Division, Housing
Department
Hideaki SUMIKURA, Dr.Eng, Researcher of Housing Production Division, Housing Department
Satoshi ARIKAWA, Dr.Eng, Professor, Department of Architecture, Tohoku Institute ofTechnology(The former Head of Residential Environment Planning Division, Housing Department)
3.3.11 Cities and Towns
Yoshiyuki SHIBATA, Director, Urban Planning Department
Tatsuo AKASHI, Dr.Eng, Head of Urban Planning Division, Urban Planning Department
Masamiki OHASHI, Senior Researcher of Urban Planning Division, Urban Planning Department
Tomohiko SAKATA, Dr.Eng, Senior Researcher of Urban Planning Division, Urban Planning
Department
Nozomu KIUCHI, Dr.Eng, Head of Urban Disaster Mitigation Division, Urban Planning
Department
Shuichi TAKEYA, Dr.Eng, Head of Construction Economics Division, Research Center for Land
and Construction Management
3.3.12 Parks and Green Spaces
Yasuo IIZUKA, Senior Researcher of Landscape and Ecology Division, Environment
Department
Masahiko MATSUE, Associate Executive Director, Ecological Urban Development Department,
Prefectural Land Development Bureau, Kanagawa Prefectural Government(The former Head of Landscape and Ecology Division, Environment Department)
3.3.13 Disaster Management
Hidetoshi KOHASHI, Dr.Eng, Research Coordinator for Construction Management, ResearchCenter for Land and Construction Management
Nozomu MORI, Director, Road Department(The former Research Coordinator for Construction Management, Research Center for Land
and Construction Management)
3.3.14. Information Field
3.3.14.1 Provision of information during Disaster or Recovery
Fumihiko KANAZAWA, Head of Intelligent Transport System Division, Research Center for
Advanced Information TechnologyviJunpei SAWA, Senior Researcher of Intelligent Transport System Division, Research Center for
Advanced Information Technology
Yoshihiro TANAKA, Researcher of Intelligent Transport System Division, Research Center for
Advanced Information Technology
Daisuke WATANABE, Researcher of Intelligent Transport System Division, Research Center for
Advanced Information Technology
3.3.14.2 Correction of coordinates of road ground control points and fundamental geospatial data ofroads
Koichi SHIGETAKA, Head of Information Technology Division, Research Center for Advanced
Information Technology
Shunsuke KANKAKU, Senior Researcher of Information Technology Division, Research Center
for Advanced Information Technology
Ryuichi IMAI, Dr.Eng, Researcher of Information Technology Division, Research Center for
Advanced Information Technology
Yuuki IBOSHI, Researcher of Information Technology Division, Research Center for Advanced
Information Technology
Naomi YUASA, Researcher of Information Technology Division, Research Center for Advanced
Information Technology
Katsuyoshi YOKOCHI, Visiting Researcher ofInformation Technology Division, ResearchCenter for Advanced Information Technology
Yoichi SASAKI, Visiting Researcher of Information Technology Division, Research Center for
Advanced Information Technology
3.3.15 Coastal Environment Area
Keita FURUKAWA, Dr.Eng, Research Coordinator for Coastal and Marine Affairs, Coastal,Marine and Disaster Prevention Department
Tomoya OKADA, Dr.Eng, Head of Marine Environment Division, Coastal, Marine and Disaster
Prevention Department
3.3.16 River Environment Area
Keigo NAKAMURA, Dr.Eng, Senior Researcher of River Environment Division, Environment
Department
3.4 Research Study
3.4.2 Research on Multiple Defense Systems and Tsunami Disaster Mitigation
Yoshio SUWA, Head of Coast Division, River Department
Fuminori KATO, Senior Researcher of Coast Division, River Department
Satoshi HATOGAI, Researcher of Coast Division, River Department
Kunihiro WATANABE, D.Agr., Researcher of Coast Division, River Department
Atsushi HATTORI, Dr.Eng, Head of River Division, River Department
Masaki FUKUSHIMA, Dr.Eng, Senior Researcher of River Division, River Department
3.4.3 Research on technologies for disaster reduction planning in coastal cities
Yoshiyuki SHIBATA, Director, Urban Planning Department
Tatsuo AKASHI, Dr.Eng, Head of Urban Planning Division, Urban Planning Department
Masamiki OHASHI, Senior Researcher of Urban Planning Division, Urban Planning Department
Nozomu KIUCHI, Dr.Eng, Head of Urban Disaster Mitigation Division, Urban Planning
Departmentvii

Hideki YOSHIOKA, Dr.Eng, Senior Researcher of Urban Disaster Mitigation Division, Urban
Planning Department
Wataru KATSUMATA, Dr.Eng, Senior Researcher of Urban Development Division, Urban
Planning Department
Shuichi TAKEYA, Dr.Eng, Head of Construction Economics Division, Research Center for Land
and Construction Management
Tatsuya IWAMI, Senior Researcher of Construction Economics Division, Research Center forLand and Construction Management
3.4.4 Research on Risk and Crisis Management Strategy for Excessive and Multiple Actions of Natural
Disasters
Atsushi HATTORI, Dr.Eng, Head of River Division, River Department
Masaki FUKUSHIMA, Dr.Eng, Senior Researcher of River Division, River Department
Tatsuro MATSUURA, Researcher of River Division, River Department
Tomohiro YOSHIKAWA, Research Coordinator for Sediment-related Disaster Prevention,
Research Center for Disaster Management
Shigeki UNJOH, Dr.Eng, Research Coordinator for Earthquake Disaster Prevention, ResearchCenter for Disaster Management
Masaki MIZUNO, Senior Researcher of Erosion and Sediment Control Division, ResearchCenter for Disaster Management
Yuji KIMURA, Senior Researcher of Earthquake Disaster Prevention Division, Research Center
for Disaster Management
3.4.5 Research and Development in Information and Technology Area
3.4.5.1 Research on the platform development for collecting and analyzing movement of people
Syunichi HAMADA, Research Coordinator for Green–Innovation, Research Center for
Advanced Information Technology
Koichi SHIGETAKA, Head of Information Technology Divison, Research Center for Advanced
Information Technology
Ryuichi IMAI, Dr.Eng, Researcher of Information Technology Division, Research Center for
Advanced Information Technology
Yuuki IBOSHI, Researcher of Information Technology Division, Research Center for Advanced
Information Technology
3.4.5.2 Research on supportive use of 3D CAD data for disaster rehabilitation processes
Masataka HIRAJO, Research Coordinator for Advanced Information Technology, ResearchCenter for Advanced Information Technology
Ryuichi IMAI, Dr.Eng, Researcher of Information Technology Division, Research Center for
Advanced Information Technology
3.4.5.3 Research on the management method of buried debris using computer aided construction
technology
Koichi SHIGETAKA, Head of Information Technology Division, Research Center for Advanced
Information Technology
Hiroki KAJITA, Senior Researcher of Information Technology Divison, Research Center for
Advanced Information Technology
Jun KITAGAWA, Researcher of Information Technology Division, Research Center for
Advanced Information Technologyviii

3.4.5.4 Research on Bridge Monitoring Technology using 3D CAD Design Data
Koichi SHIGETAKA, Head of Information Technology Division, Research Center for Advanced
Information Technology
Noriaki AOYAMA, Senior Researcher of Information Technology Division, Research Center for
Advanced Information Technology
4. Lessons learned and Future Tasks Concerning Disaster Countermeasures and Risk Management
Hiroyuki KISHIDA, Dr.Eng, Executive Director for Research Affairs
Afterword
Hiroyuki KISHIDA, Dr.Eng, Executive Director for Research Affairs(Editorial Committee Member)
Akinori KANAI, Deputy Director-General(The former Executive Director for Building Research, Building Research Institute)
Hiroyuki KISHIDA, Dr.Eng, Executive Director for Research Affairs
Hiroshi TANNO, Coordinator for Research Planning, Planning and Research Administration
Department
Naokazu TAKADA, Research Coordinator for Coastal and Marine Disaster Prevention, Coastal,Marine and Disaster Prevention Department
Shigeki UNJOH, Dr.Eng, Research Coordinator for Earthquake Disaster Prevention, ResearchCenter for Disaster Management
Akio MIZUTANI, Director, Housing Department(The former Research Coordinator for Disaster Mitigation of Building, Research Center for
Disaster Management)
Yasuo OKUDA, Dr.Eng, Research Coordinator for Disaster Mitigation of Building, ResearchCenter for Disaster Management(The former Research Coordinator for Advanced Building Technology, Building Department)ix

1. Introduction
On March 11, 2011 at 14:46, a megaquake with acommenced in response to new challenges that became

moment magnitude of 9.0 occurred, with the hypocenterapparent from the disaster.

located off the Sanriku coast. As well as causing strong

This report contains details of the following.

tremors across an extensive area, a massive tsunami

1) The Great East Japan Earthquake and the responses

was observed on the Pacific coast, and coastal areas into this by the national government, MLIT, and NILIM

the Tohoku and Kanto regions in particular suffered

As well as providing a summary in chronological ordercatastrophic damage. The Japan Meteorological Agencyof responses by the government and MLIT aimed at

named this earthquake the “2011 off the Pacific coast of

recovery and reconstruction, NILIM has compiled a

Tohoku Earthquake”. The disaster consisting of thesummary of the initiatives that it implemented as part ofearthquake off the Pacific coast of Tohoku and thethis disaster response.

resultant nuclear power plant accident has come to be2) Initiatives focused on recovery and reconstruction

called the “Great East Japan Earthquake”. According tofollowing the Great East Japan Earthquake

the National Police Agency, as of January 16, 2013,
there had been 15,879 deaths due to the earthquake,while the number of missing persons was 2,700 andthe number of those injured had risen to 6,1321).

As well as summarizing the deliberations concerning
such matters as the technical standardization of recovery
and reconstruction measures in the fields under MLIT’s
jurisdiction and NILIM’s mission, including erosion control,

At the time of the Great East Japan Earthquake, as asewerage systems, rivers, water resources, coasts, roads,

member of bodies such as the Technical Emergency

harbors, airports, and buildings, NILIM has compiled aControl Forces (TEC-FORCE) established by the Ministrysummary in chronological order of the specific ways inof Land, Infrastructure, Transport and Tourism (hereinafter

which it contributed to these deliberations, focusingreferred to as MLIT), the National Institute for Land andprimarily on the following.
① Status of responses in various situations in relation

Infrastructure Management (hereinafter referred to as
NILIM) conducted emergency damage studies andtodamagesurveys,damage analysis on facilities within MLIT’s jurisdiction anddeliberations

NILIM’s research fields in partnership with various

countermeasures, legislation, establishment ofrelevant organizations, including the Public Workstechnical standards, and practical application at

Research Institute, the Building Research Institute, andconstruction

the Port and Airport Research Institute. NILIM has played

starting new studies)anddamageproposals

analysis,concerningand recovery sites (including

significant roles to date as a research institute affiliated to② Participation by NILIM in various expert technical

MLIT, thorough the implementation of various endeavors

review committees established by MLIT and otherincludingconcerning

bodies in order to consider decisions on such

emergency measures, as well as providing technicalmatters as policies on rapid recovery; in addition,

support in relation to legislation and the review of

specific content such as technical support

technical

implemented in partnership with the secretariats ofdeliberations

standards,

and

and

proposals

technical

supportat

infrastructure construction and recovery sites. As well as

these committees.

steadily linking results of those efforts to the recovery and③ Proposals for technological policy measures to bereconstruction of damaged areas, it is essential that

included in legislation and technical standards, as

NILIM identifies further issues and ceaselessly strive forwell as the results of damage surveys andimprovements, in order to prepare for future disasters.

analyses carried out in order to obtain technicalThis report has been compiled in chronological order,

evidence for thesedetailing the responses and measures implemented by④ Examples of effective responses, and cases in

NILIM, as well as describing the initiatives thatwhich the response was thought not to have been1

adequate enough. Items identified as being issues
or regarding which improvements could be made.
This report focuses on initiatives by NILIM during the 18
months after the earthquake occurred (up to the end of
October 2012). There are fields in which deliberations
continue to be carried out, and details of these will be
provided in a report to be published at a later date.
Please note that the following abbreviations are usedconsistently in this report:・

National Institute for Land and InfrastructureManagement → NILIM・ Ministry of Land, Infrastructure, Transport and Tourism→ MLIT
References
1) Emergency

DisasterCountermeasures

Headquarters, National Police Agency of Japan:
Damage Situation and Police Countermeasuresassociated with the 2011 Tohoku district - off the
Pacific Ocean Earthquake. January 16, 2013.
http://www.npa.go.jp/archive/keibi/biki/higaijokyo_e.pdf

22. The Great East Japan Earthquake and Responses to This by the National
Government, MLIT, and NILIM
2.1 Overview of the Earthquake and Resultant
Damagecoast of Ibaraki Prefecture, aftershocks also occurred(1) Earthquake and Ground Motion

side of the trench axis near the focal region, and shallow

over an extensive area outside it, including the eastern

At 14:46 on March 11, 2011, a megaquake with aareas on land in Fukushima and Ibaraki Prefectures. As

moment magnitude of 9.0 occurred, with the hypocenter

well as a M7.3 foreshock two days before the main

located off the Sanriku coast (latitude 38.1° north,quake, 840 aftershocks measuring M4.0 or more

1)longitude 142.9° east) . The focal depth was 24km. Thisoccurred during the 60 days after the main quake, andearthquake (M9.0) was the largest in Japanese recorded

there were five aftershocks in excess of M7.0. The

history; even on a global scale, it is the fourth-largest inbiggest aftershock was an M7.7 earthquake thatrecorded history worldwide, behind the 1960 Valdivia

occurred off the coast of Ibaraki Prefecture at 15:15 onearthquake in Chile (M9.5), the 1964 Alaska earthquake

March 11. Furthermore, earthquakes with a seismic(M9.2), and the 2004 Indian Ocean earthquake andintensity ranging as high as 6-upper were observed intsunami (M9.1).

the Izu region of Shizuoka Prefecture (March 11) and in

At 14:49 on March 11, the Japan Meteorologicalthe east of that prefecture (March 15), as well as inAgency announced the earthquake magnitude to benorthern Nagano Prefecture (March 12); although one

M7.9 (preliminary report). This was the Meteorologicalcannot deny the possibility that these occurred as a

Agency's own estimate of the magnitude, calculated

result of the Great East Japan Earthquake, thefrom the amplitude of the seismic wave. Subsequently,

relationship between them is not necessarily clear.

using the moment magnitude obtained from Centroid

Figures 2.3 and 2.4 compare the changes over time in

Moment Tensor (CMT) analysis, the figure was revised

the number of aftershocks that occurred following major

to M8.4 at 16:00 the same day (Meteorological Agency

earthquakes in marine areas and inland earthquakes inmagnitude: provisional figure), to M8.8 at 17:30 the same

recent years. There is a tendency for most aftershocks today (moment magnitude), and to M9.0 at 12:55 on

occur in the immediate aftermath of the main quake, but

March 13 (moment magnitude).

the actual number of aftershocks differs considerably

Figure 2.1 shows the distribution of seismic intensity

between earthquakes. In relation to earthquakes inand location of the epicenter, as published by themarine areas, the number of aftershocks following theMeteorological Agency, with an annotation showing theM9.0 Great East Japan Earthquake was more than three

focal region. As well as the seismic intensity of 7

times higher than the number recorded after previous

recorded in Kurihara, Miyagi Prefecture, tremors with anearthquakes.

intensity of 6-upper were observed in Miyagi, Fukushima,
Ibaraki, and Tochigi Prefectures, while tremors ranging
from 6-lower to 1 were recorded over an extensive area
ranging from Hokkaido to Kyushu.
Figure 2.2 shows the aftershocks that occurred2)-3)

following the Great East Japan Earthquake
providesasummaryofthese. Table 2.1

earthquakes

inchronological order. In addition to the tremors clustered
within the focal region, which measured approximately
500km long by about 200km wide, stretching from thearea off the coast of Iwate Prefecture to the area off the3

Figure 2.2 Areas Where Aftershocks Occurred Following
2)

the Great East Japan Earthquake (M9.0)
Figure 2.1 Distribution of Seismic Intensity by the Meteorological Agency(annotated version of diagram published by the Meteorological Agency)

Table 2.1 Earthquake Occurrence (earthquakes with a seismic intensity of at least 5-lower)
Date
March 11, 14:46

Name of Epicentral

Hypocenter Latitude (Latitude North) /RegionLongitude (Longitude East) / Depth

Off the Sanriku Coast

38°06.2′N/142°51.6′E/24km

Magnitude*

Maximum Seismic
Intensity

9.0

7 (Kurihara, Miyagi
Prefecture)

14:51

Off the coast of

36°44.0’N/142°01.7’E/11km

6.8

Fukushima Prefecture
14:54

Off the coast of

Ibaraki Prefecture)
37°30.0’N/ 141°19.8’E/36km

5.8

Fukushima Prefecture
Northern Ibaraki

5-lower (Kasama,
5-lower (Namie,
Fukushima Prefecture)

36°43.0’N/140°34.5’E/9km

5.7

37°40.5’N/141°54.6’E/23km

6.4

Prefecture
14:58

Off the coast of
Fukushima Prefecture

14:57

Off the coast of Iwate

5-lower (Ogawara,
Miyagi Prefecture)

39°11.7’N/142°22.9’E/24km

5.7

39°02.5’N/142°23.8’E/27km

6.4

Prefecture
15:06

Off the coast of Iwate
Prefecture

5-lower (Yahaba & othermunicipalities, Iwate
Prefecture)

15:08

Izu region, Shizuoka

35°10.8’N/139°01.5’E/6km

4.6

Prefecture
15:08

Off the coast of Iwate

5-lower (Atami,
Shizuoka Prefecture)

39°50.3’N/142°46.8’E/32km

7.4

Prefecture

5-lower (Gonohe & othermunicipalities, Aomori
Prefecture)

15:12

Off the coast of

37°12.2’N/141°39.6’E/27km

6.1

5-lower (Kawauchi,

Fukushima Prefecture

39°26.5’N/142°05.7’E/33km

4.8

Fukushima Prefecture)4

Off the coast of Iwate
Prefecture
15:15

Off the coast of Ibaraki

36°06.5’N/141°15.9’E/43km

7.7

Prefecture)

Prefecture
15:17

Off the coast of Ibaraki

6-upper (Hokota, Ibaraki

35°57.5’N/141°04.1’E/33km

5.7

37°50.2’N/144°53.6’E/34km

7.5

Prefecture
15:25

Off the Sanriku Coast

4 (Urakawa & othermunicipalities,
Hokkaido)

16:29

Off the coast of Iwate

39°01.8’N/142°16.8’E/36km

6.5

Prefecture)

Prefecture
16:28

Off the coast of

5-upper (Osaki, Miyagi

36°54.3’N/141°52.2’E/26km

6.2

37°21.3’N/141°16.8’E/27km

6.3

37°25.5’N/141°19.0’E/27km

6.1

Fukushima Prefecture
16:30

Off the coast of
Fukushima Prefecture

17:40

Off the coast of
Fukushima Prefecture

20:36

Off the coast of Iwate

Fukushima Prefecture)
39°10.1’N/142°37.1’E/24km

6.7

Prefecture
March 12, 03:59

Northern Nagano
Northern Nagano

36°59.1’N/138°35.8’E/8km

6.7

Northern Nagano

36°56.9’N/138°34.3’E/1km

5.9

Off the coast of

6-lower (Sakae, Nagano
Prefecture)

36°58.3’N/138°35.4’E/4km

5.3

Prefecture
22:15

6-upper (Sakae,
Nagano Prefecture)

Prefecture
05:42

5-lower (Takizawa, Iwate
Prefecture)

Prefecture
04:31

5-upper (Tomioka,

6-lower (Sakae, Nagano
Prefecture)

37°11.8’N/141°25.5’E/40km

6.2

Fukushima Prefecture

5-lower (Naraha & othermunicipalities,
Fukushima Prefecture)

23:34

Northern Nagano

36°58.0’N/138°34.0’E/5km

3.7

Prefecture
March 13, 08:24

Off the coast of Miyagi

Prefecture)
38°00.7’N/141°56.9’E/15km

6.2

Prefecture
March 14, 10:02

Off the coast of Ibaraki
Eastern Shizuoka

36°27.5’N/141°07.5’E/32km

6.2

Off the eastern coast of

35°18.5’N/138°42.8’E/14km

6.4

Northern Ibaraki

35°50.2’N/140°54.3’E/10km

6.1

Hamadori, Fukushima

36°47.0’N/140°34.2’E/5km

6.1

Hamadori, Fukushima

5-upper (Hitachi, Ibaraki
Prefecture)

37°05.0’N/140°47.2’E/8km

6.0

5-upper (Iwaki,
Fukushima Prefecture)

Prefecture
07:13

5-lower (Mito, Ibaraki
Prefecture)

Prefecture
March 23, 07:12

6-upper (Fujinomiya,
Shizuoka Prefecture)

Chiba Prefecture
March 19, 18:56

5-lower (Hokota, Ibaraki
Prefecture)

Prefecture
March 16, 12:52

5-lower (Tome, Miyagi
Prefecture)

Prefecture
March 15, 22:31

5-lower (Sakae, Nagano

37°02.1’N/140°46.1’E/1km

Prefecture

5

5.8

March 23, 07:34

Hamadori, Fukushima

37°05.8’N/140°47.7’E/7km

5.5

Prefecture
07:36

Hamadori, Fukushima

Fukushima Prefecture)
37°03.8’N/140°46.2’E/7km

5.8

Prefecture
18:55

Hamadori, Fukushima
Southern Ibaraki

37°06.6’N/140°45.6’E/9km

4.7

Off the coast of Iwate

36°10.6’N/140°02.5’E/52km

4.8

Off the coast of Miyagi

39°04.6’N/142°21.4’E/34km

6.2

Off the coast of Miyagi

5-lower (Ishinomaki,
Miyagi Prefecture)

38°23.5’Ｎ 142°18.9’Ｅ 31km

6.5

Prefecture
March 31, 16:15

5-lower (Hokota, Ibaraki
Prefecture)

Prefecture
March 28, 07:23

5-upper (Iwaki,
Fukushima Prefecture)

Prefecture
17:20

5-lower (Iwaki,
Fukushima Prefecture)

Prefecture
March 24, 08:56

5-upper (Iwaki,

5-lower (Ishinomaki,
Miyagi Prefecture)

38°52.3’Ｎ 142°05.0’Ｅ 47km

Prefecture

6.1

5-lower (Hanamaki,
Iwate Prefecture)*) Magnitude refers to moment magnitude

Figure 2.4 Comparison of the Number of Aftershocks
Following Major Earthquakes in Inland Areas4),5)(including the main quake) (magnitude 4.0 or higher)

At the same time, as far as inland earthquakes areconcerned, the 2004 Chuetsu Earthquake in Niigata
Prefecture is the earthquake that has been associatedwith the greatest amount of aftershock activity in recent
Figure 2.3 Comparison of the Number of Aftershocks

years, with aftershocks increasing the damage from the4)-5)

Following Major Earthquakes in Marine Areas

main quake and hampering emergency activities
3).

Figure 2.5 shows the results of a long-term evaluation(including the main quake) (magnitude 5.0 or higher)of a major subduction-zone earthquake by the6)

Headquarters for Earthquake Research Promotion .
This evaluation was carried out on January 11, 2011,6before the Great East Japan Earthquake. The focal
region of the earthquake was projected to extend fromthe waters offshore from Iwate Prefecture to the area off
the coast of Ibaraki Prefecture, measuring more thanabout 400km long and around 200km wide, with thelargest slip estimated to be more than 20m. The areas
where large slips occurred are regarded as the southernpart of the Sanriku offshore area (near the Japan Trench)and part of the area between the northern part of theSanriku offshore area and the Boso offshore area, basedon the evaluation by the Earthquake ResearchCommittee of the aforementioned Headquarters. The
focal region is estimated to have covered an area that
also encompassed the middle part of the Sanriku
offshore area, the Miyagi offshore area, the Fukushima
offshore area, and the Ibaraki offshore area. The
Earthquake Research Committee had conducted anevaluation of seismic motion and tsunami in the Miyagi
offshore area and individual sectors from the southern

Figure2.5

Long-term

Evaluation

of

a

Major

part of the Sanriku offshore area (near the Japan Trench),

Subduction-zone Earthquake (as of January 11, 2011) by

to the east, to the Ibaraki offshore area to the south, but it

the Headquarters for Earthquake Research Promotion,
6)

and the Great East Japan Earthquake

did not conduct an evaluation involving an earthquake inwhich all of these sectors were synchronized.

(2) Tsunami

Thus, it has been pointed out that a major feature of
the Great East Japan Earthquake was the fact that it was

Due to Great East Japan Earthquake, tsunamis werean M9.0 megaquake occurring in synchronization in

observed along the Pacific coast of the Tohoku region, as

several focal regions in the Japan Trench, something thatwell as in other coastal areas nationwide, causing

could not have been forecast from any records in Japanimmense damage. As well as the massive tsunami

over the last several hundred years.

observed at the Meteorological Agency's tsunami
observation facilities in each area, primarily on the Pacificcoast of East Japan, such as a wave in excess of 9.3m
at Soma in Fukushima Prefecture, and a wave of morethan 8.6m in the Ayukawa district of Ishinomaki in Miyagi
Prefecture, tsunami measuring at least 1m wereobserved along the Pacific coast from Hokkaido to
Kagoshima Prefecture, as well as in the Ogasawara
1)Islands . In addition, with regard to the aforementioned
tsunami heights, there was a period during which data
could not be obtained, as the observation facilities weredamaged by the tsunami, so there is a possibility that thewaves that followed were even higher.
At 14:49, three minutes after the seismic wave wasinitially detected, the Meteorological Agency issued
tsunami warnings (major tsunami) for the coastal areasof Iwate, Miyagi and Fukushima Prefectures, and7

tsunami warnings (tsunami) and tsunami advisories forremarkably high. The largest tsunami height was thethe Pacific coast from Hokkaido to Kyushu, as well as the

6.7m wave (offshore height) recorded at 15:12;

Ogasawara Islands. Subsequently, a succession of

converting the figures to the height at the point where thefollow-up reports expanding the scope of the tsunami

water was 15m deep, this wave had grown to aroundwarnings and tsunami advisories were issued, with

13m by the time it actually reached the coastal area. It

tsunami warnings and tsunami advisories being issued

was reported that the crest of the first wave wasfor the whole of the Japanese coast at 03:20 on Marchremarkably high, with crest height gradually diminishing

12 (see Table 2.2). After the alert issued for Kochi

between the second and seventh waves; furthermore,

Prefecture at 22:53 the same day, the alerts were

the fourth to seventh waves had a different shape fromprogressively downgraded to tsunami warnings andthat of the first to third waves, with repeated waves attsunami advisories, with all tsunami advisories being

intervals of around 50 minutes.
The Geospatial Information Authority of Japan

lifted at 17:58 on March 13.
Figure 2.6 shows the tsunami heights estimated on theinterpreted the inundation range of the tsunami usingbasis of data such as the position of tsunami traces

such information as the aerial photographs that it took,

obtainedtheand estimated the inundation range and the area flooded

Meteorological Agency at its tsunami observationin each municipality . Figure 2.10 shows the tsunami

facilities and in surrounding areas. In certain locations,inundation range in the Sendai district. An area stretchingtsunami traces in excess of 10m were found. Moreover,more than 4km inland on the Sendai Plain was flooded

Figure 2.7 shows the tsunami inundation heights andby the tsunami.

from

field

surveysconductedby

9)

runup heights determined through surveys by the 2011

As shown in Table 2.5, the approximate figures for

Tohoku Earthquake Tsunami Joint Survey Group (related

inundation range cover 62 municipalities in the six

academic associations, including the Japan Society ofprefectures of Aomori, Iwate, Miyagi, Fukushima, Ibaraki,

Civil Engineers). It has been reported that a tsunami ofand Chiba, with the total area flooded estimated to total

up to 30m in height struck the coast from Iwate

561km .

2

Prefecture to Miyagi Prefecture, causing catastrophic
damage.
Figure 2.8 shows examples of tsunami waveforms
1)

recorded by the Meteorological Agency . There areobservation points where data was not obtained, due tothe massive tsunami, but it is known that there wererepeated onslaughts by the tsunami. Table 2.3 shows theobserved values for the first wave of the tsunami and theheight of the biggest wave recorded at tsunami
observation facilities within Japan. The biggest waves hit
the coast 30 minutes to an hour after the earthquake
struck.
Table 2.4 and Figure 2.9 respectively show theobserved values for the first wave of the tsunami and thehighest waves recorded using GPS wave meters thatwere then analyzed by the Port and Airport ResearchInstitute, and the waveform recorded off the coast of
Kamaishi (waters 18km offshore from Kamaishi Port,
8)with a depth of 200m) . Off the coast of Kamaishi, thefirst wave of the tsunami was the biggest, with records
showing that all the waves up to the seventh wave were8

Table 2.2 Tsunami Warnings Issued (Pacific Coast of Aomori, Iwate, Miyagi, Fukushima, Ibaraki, and Chiba
1)

Prefectures)
Date

Tsunami Warning, etc. (anticipated tsunami height)

March 11, 14:49

Aomori

Iwate

Miyagi

Fukushima

Ibaraki

Chiba

Prefecture

Prefecture

Prefecture

Prefecture

Prefecture

Prefecture

Tsunami: 1m

Major

Major

Major

Tsunami: 2m

Tsunami: 2m

tsunami: 3m

tsunami: 6m

tsunami: 3m

15:14 Major tsunami Major tsunami Major tsunami Major tsunami Major tsunami Major tsunami
3m

6m

At least 10m

15:30 Major tsunami Major tsunami
8m
16:08 Major tsunami

↑

6m

4m

3m

Major tsunami Major tsunami Major tsunami

At least 10m

At least 10m

At least 10m

At least 10m

↑

↑

↑

↑

↑

↑

↑

↑

TsunamiTsunamiwarningadvisory↑

At least 10m
March 12, 13:50
20:20
March 13, 07:30↑
TsunamiTsunamiTsunamiTsunamiTsunamiwarning

warning

warning

warningadvisory

TsunamiTsunamiTsunamiTsunami↑advisory

advisory

advisory

advisory

17:58↑

LiftedTable 2.3 Observed Values for the First Wave of the Tsunami and Size of the Highest Wave Recorded at Tsunami
1)

Observation Facilities Within Japan(Pacific Coast of Aomori, Iwate, Miyagi, Fukushima, Ibaraki, and Chiba Prefectures)
Prefecture

Name ofObservation

First Wave
Start Time

Height (+: runup; -:Point
AomoriHighest Wave
Time

Heightdrawback)

Hachinohe

11th 15:21-0.7m

11th 16:57

At least 4.2m

Miyako11th 15:01-1.24m

11th 15:26

At least 8.5m

Prefecture
Iwate
Prefecture

Ofunato11th 14:00-1.0m

11th 15:18

At least 8.0m

Kamaishi

11th 14:00-1.19m

11th 15:21

At least 4.2m

MiyagiAyukawa,

11th 14:00－

11th 15:26

At least 8.6m

Prefecture

Ishinomaki

Fukushima

Soma

11th 14:00-1.2m

11th 15:51

At least 9.3m

Prefecture

Onahama, Iwaki

11th 15:08+2.6m

11th 15:39

3.33m

IbarakiOarai

11th 15:17+1.7m

11th 16:52

4.0m

Choshi11th 15:13+2.3m

11th 17:22

2.5m

Prefecture
Chiba
Prefecture
Note: In some cases, there were periods in which data could not be obtained. Moreover, due to subsidence, there
is a possibility that the figures recorded for the first wave are inaccurate.

9

Table 2.4 Observed Values for the First Wave of the Tsunami and Size of the Highest Wave Recorded Using GPS1),8)Wave Meters
Prefectures

Name of

Water Depth

Observation PointFirst Wave
Start Time

Height (+: positive

Highest Wave
Time

Heightwave; -: negative wave)

Iwate

Off the coast ofPrefecture

Kuji
Off the coast of

125m

11th 14:56-0.4m

11th 15:19

Approx. 4.0m

200m

11th 14:48-0.5m

11th 15:12

Approx. 6.3m

204m

11th 14:48-0.5m

11th 15:12

Approx. 6.7m

160m

11th 14:47-0.4m

11th 15:14

Approx. 5.7m

137m

11th 14:49+1.0m

11th 15:15

Approx. 2.6m

210m

11th 16:09+0.5m

11th 16:26

Approx. 0.5m

201m

11th 16:23+0.3m

11th 16:38

Approx. 0.3m

MiyakoOff the coast of
Kamaishi
Off the coast ofHirota Bay
Fukushima

Off the coast ofPrefecture

OnahamaMie

Off the coast ofPrefecture

Owase

Wakayama

Off the coast ofPrefecture

ShirahamaNote: In some cases, there were periods in which data could not be obtained.

10Note: Arrows indicate that there was aperiod during which data could not be
obtained, as the observation facilities weredamaged as a result of the tsunami, andthere is, therefore, a possibility that thewaves that followed were even higher.
1)

Figure 2.6 Tsunami Height Recorded at Tsunami Observation Facilities

7)

Figure 2.7 Tsunami Inundation Height and Runup Height

11

1)

Figure 2.8 Tsunami Waveforms Recorded at Major Tsunami Observation Facilities (2.0m or more)

8)

Figure 2.9 Tsunami Waveform Recorded Using a GPS Wave Meter (off the coast of Kamaishi)

12there was displacement on the Pacific side of up to
530cm (Oshika) in a horizontal direction, while in a
vertical direction, there was subsidence of up to 120cm(Oshika).
The maps in Figure 2.12 were published by the
Ministry of Land, Infrastructure, Transport and Tourism
Tohoku Regional Development Bureau and show thesituation on the Sendai Plain in relation to subsidence
resulting from the earthquake. An overall understandingof the situation in regard to subsidence was gained fromdata obtained via airborne laser scanning and othertechniques. Subsidence was examined in relation to2height above sea level and it was reported that 83km of
land had been below the existing highest tidal level2

before the earthquake, 3km of which was below mean
Range of tsunami flooding

sea level. In contrast, after the earthquake, the figures

extended more than 4km

were 16km and 111km respectively; thus, the area

2

2

below mean sea level had expanded by about 5.3 times.
This subsidence has caused flood damage at high tide.
(4) Liquefaction
Figure 2.10 Tsunami Inundation Range (calculated by

Extensive soil liquefaction occurred in the Hokkaido,

9)

the Geospatial Information Authority of Japan)

Tohoku and Kanto regions due to the Great East Japan
Earthquake, causing considerable damage to houses,

9)

Table 2.5 Area Flooded by Prefectureroads, river embankments, port facilities, and lifelines. In
2

Prefecture

Inundation Area (km )coastal areas of the Tohoku region, there were also

Aomori Prefecture

24

many areas in which it was not possible to confirm traces

Iwate Prefecture58

of liquefaction precisely, due to the tsunami that followed

Miyagi Prefecture327

the earthquake. The map in Figure 2.13 was compiled by

Fukushima Prefecture112

the Ministry of Land, Infrastructure, Transport and

Ibaraki Prefecture

23

Tourism Kanto Regional Development Bureau and the

Chiba Prefecture

17Japanese Geotechnical Society, and shows the results of

Total

561

surveys conducted in the Kanto region concerning thestatus of liquefaction there. Liquefaction was found tohave occurred over an extensive area, covering the(3) Ground Subsidence

seven prefectures in the Kanto region, namely Ibaraki,

The maps in Figure 2.11 were published by the

Tochigi, Gunma, Saitama, Chiba, Tokyo, and Kanagawa.

Geospatial Information Authority of Japan and show

The northernmost point was in Otawara in Tochigi

10)

diastrophism inland and in marine areas . They show
diastrophism identified via the Geospatial Information

Prefecture, the westernmost point was Kumagaya in

Authority of Japan's continuous GPS monitoring system

Saitama Prefecture, the southernmost point was
Minamiboso in Chiba Prefecture, and the easternmost(GEONET), in the case of inland areas, and via seafloor

point was Choshi, also in Chiba Prefecture. Liquefaction

geodetic observation carried out by the Hydrographic

was seen to be concentrated along the lower reaches ofand Oceanographic Department of the Japan Coast

the Tone River and the coast of Tokyo Bay from Tokyo to

Guard, in the case of marine areas. It was reported that

Chiba, with other patches of liquefaction spread across13

areas including the Kawasaki and Yokohama area, themunicipalities throughout the Kanto region; looking at the

Naka River and Kuji River areas, the middle reaches ofsituation

the Tone River, the Kinu and Kokai River basin, and themunicipalities affected was in Ibaraki Prefecture, close to

old Tone River basin.

the hypocenter, where 36 cities, towns, and villages werebyprefecture,thelargestnumberofaffected, followed by Chiba Prefecture, where 25 were

Reports of liquefaction by prefecture and byaffected.

municipality were as shown in Table 2.6. Liquefaction
was confirmed to have occurred in at least 96(a) Horizontal(b) VerticalFigure 2.11 Diastrophism Inland and in Marine Areas Due to the Great East Japan Earthquake (compiled by the10)

Geospatial Information Authority of Japan)

14

11)

Figure 2.12 Subsidence on the Sendai Plain Resulting from the Earthquake

15

12)

Figure 2.13 Distribution of Areas of Liquefaction in the Kanto Region
12)

Table 2.6 Municipalities with Areas of Liquefaction
Prefecture

Municipality

Number of
Municipalities Suffering
Liquefaction

Ibaraki Prefecture

Mito, Hitachi, Tsuchiura, Koga, Ishioka, Yuki, Ryugasaki, Shimotsuma, Joso,

36

Hitachiota, Kitaibaraki, Toride, Tsukuba, Hitachinaka, Kashima, Itako, Moriya,
Naka, Chikusei, Bando, Inashiki, Kasumigaura, Kamisu, Namegata, Hokota,
Tsukubamirai, Ibaraki Town, Oarai, Tokai, Miho, Ami, Kawachi, Yachiyo,Goka, Sakai, Tone
Tochigi Prefecture

Tochigi City, Mooka, Otawara

3

Gunma Prefecture

Tatebayashi, Itakura, Ora

3

Saitama Prefecture

Saitama City, Kumagaya, Kawaguchi, Gyoda, Kazo, Kasugabe, Hanyu,

16

Koshigaya, Toda, Hatogaya, Wako, Kuki, Yashio, Satte, Yoshikawa,
Miyashiro
Chiba Prefecture

Chiba City, Choshi, Ichikawa, Funabashi, Kisarazu, Matsudo, Noda, Narita,

25

Togane, Asahi, Narashino, Kashiwa, Yachiyo, Abiko, Urayasu, Sodegaura,
Inzai, Minamiboso, Sosa, Katori, Sanmu, Sakae, Kozaki, Tonosho, Kujukuri
Tokyo Prefecture

Chuo, Minato, Sumida, Koto, Shinagawa, Ota, Kita, Itabashi, Adachi,

11

Katsushika, Edogawa
Kanagawa
Prefecture

Yokohama, Kawasaki

2
Total

96

16

(5) Overview of Damage① Human casualties

The following provides an overview of the damage

15,879 deaths, 2,700 missing, 6,132 injured

resulting from the Great East Japan Earthquake.

② Damage to buildings
128,911 completely destroyed, 268,882 partially

1) Human Casualties and Damage to Homes

destroyed, 733,719 with significant partial damage

Based on figures published by the National Police

19,790 flooded above floor level, 15,630 flooded below

Agency, the total casualties and damage as of January 16,
13)2013 are as follows . Table 2.7 summarizes the humanfloor levelcasualties and damage to buildings by prefecture.

③ Fires (completely/partially burnt)
279
13)

Table 2.7 Figures for Human Casualties and Damage to Buildings by Prefecture(Figures published by the Emergency Disaster Countermeasures Headquarters, current as of January 16, 2013)
Prefecture
Name

Human Casualties
DeathsMissing

Damage to Buildings (Damage to Homes)

Injuries

destroyed

Significant
partialdamageFloodedabove
floor level

Flooded
below
floor
level

4

7

329

545

Completely

Partially

destroyed3

Fires(completely/
partiallyburnt)

Hokkaido

1

Aomori

3

1

111

308

701

1,006

4,673

1,171

208

18,370

6,501

13,000

1,761

323

15

9,534

1,314

4,144

85,414

152,523

224,162

14,67812,894

135

1,061

338

80

Prefecture
Iwate
Prefecture
MiyagiPrefecture
Akita

11

3

29

21

Prefecture
Yamagata2

Prefecture
Fukushima

1,606

211

182

21,096

72,390163,007

117

15

198

4,847

711

2,623

24,178

183,617

4

135

261

2,109

72,4001

39

7

17,246Prefecture
Tokyo

7

1

Prefecture
Ibaraki

24

1

1,798

779

31

1

2

728

15

Prefecture
Tochigi
Prefecture
Gunma
Prefecture
Saitama

45

24

199

1,800

252

800

10,03352,12439

445

Prefecture
Chiba

20

2

Prefecture
Kanagawa

4134

Prefecture
Niigata317Prefecture17

157

Yamanashi

24Prefecture
Nagano1

Prefecture
Shizuoka

3

13

5

Prefecture
Mie

1

2

Prefecture
Tokushima

2

9

2

8

19,79015,630Prefecture
Kochi

1

Prefecture
Total

15,879

2,700

6,132

128,911

268,882

733,719279

Note: The total figures as of September 28, 2012 for casualties and damage compiled by the Fire and Disaster
14)

Management Agency on the basis of reports by prefectures are as follows .
(i) Human casualties: 18,131 deaths, 2,829 missing, 6,194 injured(ii) Damage to buildings (damage to homes): 129,391 completely destroyed, 265,096 partially destroyed, 743,298 withsignificant partial damage, 20,580 flooded above floor level, 15,629 flooded below floor level(iii) Fires: 330(disaster waste: 18.02 million tons; tsunami deposits:2) Amount of Debris
The amount of debris from houses and other9.56 million tons) (as of August 2012). According to this,structures toppled by the tsunami has been estimated bydisposal of 4.42 million tons (about 25%) of the 18.02

15)

the Ministry of the Environment . As shown in Table 2.8,

million tons of disaster waste had been completed by thethe total amount for the three prefectures of Iwate, Miyagi,

three disaster-stricken coastal municipalities as of theand Fukushima is estimated at 27.58 million tons

end of July 2012.

Table 2.8 Disposal Status of Disaster Waste, etc. in the Three Coastal Prefectures
Disaster Waste

Estimated
Amount of

Estimated

DisasterAmountWaste, etc.

(10,000t)

Tsunami Deposits
Estimated

AmountProportion(10,000t)(%)(10,000t)

Iwate

InterimAmountQuantity

Proportion

Interim

Target(10,000t)(10,000t)(%)

Target

(%)

(%)

525

395

81

21

58

130

0.3

0

50

1,873

1,200

331

28

59

672

74

11

40

361

207

30

15

-

153

1.6

1

-

2,758

1,802

442

25

-

956

76

8

-

Prefecture
MiyagiPrefecture
Fukushima
Prefecture
Total3) Estimated Cost of Damage

disaster-afflicted areas has been estimated by the16)

Cabinet Office (disaster management section) . Table

The cost of the damage to stock (buildings, lifeline
facilities,

socialinfrastructure

facilities,etc.)

2.9 shows the estimated cost of damage to each type ofin18

facility, with the total estimated at approximately 16.9

economic research); two cases were assumed for thetrillion yen. This is around 1.8 times more than the cost ofbuilding damage rate, but the focus differs between

damage resulting from the 1995 Great Hanshin Awaji

prefectures, so a simple comparison is not possible, but

Earthquake.

the approximate total cost of damage to stock is

Moreover, the cost of damage to stock has also been

estimated to be in the range of 16-25 trillion yen.

estimated by the Cabinet Office (section in charge of
16)

Table 2.9 Estimated Cost of Damage
Category

Cost ofReference: Great

DamageHanshin Awaji
Earthquake

Buildings, etc.

Approx. 10.4

Approx. 6.3 trillion(houses, residential land, shops, offices, factories, machinery, etc.)

trillion yen

yenLifeline facilities

Approx. 1.3

Approx. 0.6 trillion(water supply, gas, electricity, and communications & broadcasting

trillion yen

yenSocial infrastructure facilities

Approx. 2.2

Approx. 2.2 trillion(rivers, roads, ports, sewerage systems, airports, etc.)

trillion yen

yen

Agriculture, forestry & fisheries infrastructure

Approx. 1.9(agricultural land & facilities, forest land, fisheries facilities, etc.)

trillion yen

Approx. 0.5 trillion

Other (education & cultural facilities, health preservation, medical care

Approx. 1.1

yen& welfare facilities, waste disposal facilities, other public facilities, etc.)

trillion yen

Total

Approx. 16.9

Approx. 9.6 trillion

trillion yen

yenfacilities)(Note) These figures have been compiled by the Cabinet Office (section in charge of disaster prevention) based on information provided
by each prefecture and relevant government ministries and agencies concerning the cost of damage to stock (buildings, lifeline
facilities, social infrastructure facilities, etc.) These figures may change in future, as the details of the damage emerge. Moreover,totals may not add up, due to rounding. Please note that these figures do not include the cost of damage associated with thenuclear power plant accident. Figures for the cost of damage resulting from the Great Hanshin Awaji Earthquake werecompiled by the National Land Agency (according to estimates by Hyogo Prefecture, the total cost of damage from18)

the earthquake was approximately 9.9 trillion yen .)4) General Overview of Damage to Facilities Within the

Information about damage to facilities in individual fields isJurisdiction of the Ministry of Land, Infrastructure,provided in the subsequent chapters on each field, so thisTransport and Tourism

section features quotes from the FY2010 White Paper on

As the Great East Japan Earthquake was a complex

Land, Infrastructure, Transport and Tourism in Japan,

disaster in which the damage was extremely extensive,providing a general overview of damage to facilities within

due to a massive tsunami caused by a megaquake,the jurisdiction of the Ministry of Land, Infrastructure,subsidence and liquefaction, and damage caused byTransport and Tourism and the resultant impact. In

landslides and fires, which was compounded by theaddition, some figures, such as those for humaneffects of an accident at a nuclear power plant, it iscasualties, have been replaced with updated figures.

exceedingly difficult to gain a precise grasp of the damage.

19

Table 2.10 General Overview and Impact of Damage to Facilities Within the Jurisdiction of the Ministry of Land,
18)

Infrastructure, Transport and Tourism Resulting from the Great East Japan Earthquake (as of August 2011)(1) Damage in Urban Areas and Human Casualties
DamageDamage in urban
areas

Damage Situation, Damage-related Statistics, Impact
2

・Of the total of approximately 535km of land flooded in 62 municipalities in the six prefectures of Aomori,
2

Iwate, Miyagi, Fukushima, Ibaraki, and Chiba, approximately 119km was accounted for by flooding in urban
areas.
・The area of land in which most buildings were completely destroyed (including those washed away) totaled
2

approximately 99km , while the area in which the majority of buildings were mostly or partially destroyed was22

approximately 58km in total (this is a more extensive area than the approximately 35km destroyed by fireas a result of the Great Kanto Earthquake).
・In Noda and Rikuzentakata in Iwate Prefecture, Minamisanriku and Higashimatsushima in Miyagi Prefecture,and Shinchi in Fukushima Prefecture, at least 80% of the urban area was damaged due to flooding.
Human casualties(including
evacuees)

・15,879 deaths across 12 prefectures (see Table 2.7) (far in excess of the death toll from the Great Hanshin
Awaji Earthquake, this figure constitutes the largest number of fatalities since the end of the war).
・More than 99% of the deceased and missing persons were concentrated in municipalities on the Pacificcoast of the three prefectures of Iwate, Miyagi, and Fukushima.
・Of the dead, 54% were elderly people aged 65 or above (people requiring assistance to evacuate in theevent of disaster).
・There were many evacuees across a wide area, due to the combined effect of the earthquake, tsunami, andnuclear power plant accident: evacuees peaked at 468,000 on the third day after the disaster (March 14)(approximately 1.5 times the peak following the Great Hanshin Awaji Earthquake). Evacuees have dispersed
outside their home municipalities and further afield outside their home prefectures, and there are currently
evacuees residing in each of the 47 prefectures of Japan.

(2) Damage to Housing and Infrastructure (I)DamageDamage tohousing and otherbuildings

Damage Situation, Damage-related Statistics, Impact

・128,911 completely destroyed, 268,882 partially destroyed, 733,719 with significant partial damage (seeTable 2.7).
・57,928 non-residential buildings were damaged, with public facilities such as local government buildings,
schools, and hospitals suffering major damage.
・As well as buildings that were washed away by the tsunami or collapsed as a result of the seismic motion,buildings containing large spaces, such as gymnasiums and airports, suffered roof collapses.
・In order to prevent secondary disasters due to aftershocks, 95,381 emergency risk assessments ofdisaster-stricken buildings were carried out in 149 municipalities in ten prefectures (buildings deemed to be"dangerous" to enter because of the risk of collapse due to aftershocks: 11,699; buildings deemed to "requirecaution": 23,191).

Damage toresidential land

・Due to the main quake and the frequent aftershocks, damage occurred as a result of landslides and thecollapse of large tracts of land reclaimed by means of mounding.
・6,531 risk assessment surveys of disaster-stricken residential land were carried out in 56 municipalities innine prefectures (sites deemed to be "dangerous" because of the risk of the collapse of retaining walls:
1,456; sites deemed to "require caution": 2,209).
・Liquefaction occurred over an extensive area in the Tohoku and Kanto regions, including along the coast ofTokyo Bay. Many cases of damage occurred as a result, such as the ground becoming softer, leading to20

houses being left tilted at an angle.

Damage to coasts

・Diastrophism caused extensive subsidence of the ground, including along the coast of the Sendai Plain andon other level ground.
・As well as an increase in the area of land below mean sea level, the destruction of seawalls and erosion ofsand dunes along the coast led to reduced safety in regard to events such as high tides.
・With regard to the coastline in the three prefectures of Iwate, Miyagi, and Fukushima (where levee
revetments run for approximately 300km along the coast), approximately 190km of embankments werecompletely or partially destroyed.

Damage to rivers

・Damage (including the breach or collapse of embankments) occurred at 2,115 points along rivers under the
direct control of the Ministry (Kitakami River, Tone River, etc.), and at 1,360 points along rivers under thecontrol of prefectures and municipalities.
・In terms of the mechanisms of damage, as well as deformation due to liquefaction of the foundation
subgrade of the levee body, cases were also found in which deformation was presumed to have occurred
due to partial liquefaction of the levee body itself.

Damage fromlandslides

・136 landslides occurred in 12 prefectures, including Iwate, Miyagi, and Fukushima (19 deaths). In addition,
many hillside collapses were found to have occurred.

(2) Damage to Housing and Infrastructure (II)DamageTransport

Damage Situation, Damage-related Statistics, Impact
・As a result of slope failures and road bridges being washed away, 15 expressways, 69 sections of national

infrastructure:highways under the direct control of the Ministry, 102 sections of national highways under the control ofdamage to roads

prefectures, etc., and 540 sections of prefectural roads, etc. were closed to traffic.
・In particular, many sections of roads along the whole of the Pacific coast, primarily in the Tohoku region,
became impassable due to damage resulting from the tsunami, including National Route 45, which runs
along the Sanriku Coast from the city of Sendai in Miyagi Prefecture.

Transport

・As well as damage to the Tohoku, Akita, and Yamagata Shinkansen high-speed train lines, lines runninginfrastructure:along the Pacific coast in particular suffered damage, with station buildings and railway tracks being washeddamage toaway; as of 15:00 on March 13, 48 hours after the disaster struck, services remained suspended on 64 lines

railways

operated by 22 companies.

Transport

・There was immense damage to port facilities including breakwaters, berthing facilities, and cargo handlinginfrastructure:equipment at all ports on the Pacific coast from Hachinohe in Aomori Prefecture to Ibaraki Prefecture,

damage to ports

including 11 international hub ports and other major ports.
・Sea lanes and harbor facilities such as berths became clogged up with earth and sand, or containers, motor
vehicles or debris that were washed into the harbor area by the tsunami.
・156 navigation aids such as beacons, which ensure the safe passage of marine vessels, sustained damage,including some that collapsed and others that were washed away.

Transport

・Four airports (Sendai, Hanamaki, Fukushima, and Ibaraki) were affected by the disaster.

infrastructure:

・Sendai Airport was flooded by the massive tsunami, with more than 2,000 vehicles being washed up onto

damage to airports

the runway, taxiway, and apron; in addition, earth, sand, and debris were left strewn across a wide area and it
suffered immense damage, due to power generators and other electrical equipment and machinery installedin the control tower and passenger terminal being submerged.

21

・Approximately 1,400 travelers, local citizens who had evacuated there, and staff members were temporarily
stranded there, and it took about two days to complete the evacuation and rescue process.
・The Sendai Airport Access Railway, which is the main means of access to Sendai Airport, suffered damage
including the flooding of the airport tunnel and the submersion of traffic control equipment.
Transport
infrastructure:
damage to bus

・Businesses in the disaster-afflicted areas of Iwate, Miyagi, and Fukushima had a total of 219 vehicles
destroyed or washed away; in addition, their staff members and company premises were also affected by
the disaster.

transport

・Many transit bus services and highway express bus services were suspended. With particular regard tooperationstransit buses, as of April 28, a month and a half after the disaster, services on 26% of routes in the coastal
areas of both Iwate and Fukushima Prefectures, and on 19% of routes in the coastal areas of Miyagi
Prefecture remained suspended.
・Due to fuel shortages in the immediate aftermath of the disaster, the number of services operated by bus
companies in districts outside the disaster-afflicted areas were also reduced.

Damage to・Sewage treatment plants in a total of 48 locations over an extensive area, mainly on the Pacific coast of theinfrastructure for

Tohoku region, halted operations due to tsunami inundation; in addition, sewage treatment plants in 63

daily life:

locations suffered damage to facilities.

sewerage system

・It is not possible to ascertain the status of damage at nine sewage treatment plants located in the vicinity of
the TEPCO Fukushima Daiichi Nuclear Power Plant.
・Damage to sewage pipes occurred across 11 prefectures, covering a range of 550km (far in excess of thedamage resulting from the Great Hanshin Awaji Earthquake, which covered a range of 162km over two
prefectures).

Damage to urban
parks

・The tsunami caused damage including the loss of many coastal forest areas that had been developed andmaintained as urban parks.

(3) Impact on the Tokyo Metropolitan Area
DamagePeopleDamage Situation, Damage-related Statistics, Impact
・As the earthquake occurred in the afternoon on a weekday, there were many people who experienced

experiencing

difficulty in returning home, particularly from central Tokyo, because public transport services were halted sodifficulty returningthat checks and repair work could be carried out, such as the inspections and repairs required over anhomeextensive area on all of the railway lines in the Tokyo metropolitan area.

Elevators withpeople trapped

・People were trapped inside at least 210 elevators in Tokyo and 14 other prefectures outside the Tohoku
region (all were rescued by midday on March 12, the day after the disaster).

insidePower supply
shortages

・Within the area served by Tokyo Electric Power Company, in order to avoid large-scale power cuts due toshortages in power supply, planned blackouts to curb demand were carried out in each area on a rotatingbasis from March 14, with the plan announced in advance; in addition, widespread calls were made for theconservation of electricity. Services were suspended and the number of services operated reduced
considerably on the majority of railways in the Tokyo metropolitan area, which had a major impact on all
aspects of economic and social activities, including on people's ability to get to work or school.

References

http://www.jma.go.jp/jma/kishou/books/saigaiji/saigai

1) Japan Meteorological Agency: [Earthquake andji_201101/saigaiji_201101.html

Tsunami Warnings in the Event of Disaster] The

2) Japan Meteorological Agency: Areas of Aftershock

Great East Japan Earthquake

Activity22http://www.jma.go.jp/jma/menu/yoshin_area.pdf

13) National Police Agency of Japan Emergency3) Japan Meteorological Agency: Comparison of the
Numberof

Aftershocks

Following

Disaster Countermeasures Headquarters: Damage

Major

Situation and Police Countermeasures associatedEarthquakes in Marine Areas (Magnitude 5.0 orwith the 2011 Tohoku district - off the Pacific Ocean

Higher)Earthquake. January 16, 2013.

http://www.seisvol.kishou.go.jp/eq/2011_03_11_toho

http://www.npa.go.jp/archive/keibi/biki/higaijokyo.pdf

ku/yoshinhikaku.pdf

14) Fire and Disaster Management Agency Disaster4) Japan Road Association: Handbook of Road

Response Headquarters: Concerning the 2011

Earthquake Countermeasures: Measures to be

Great East Japan Earthquake (148th Report),

Taken Before an Earthquake (FY2006 Revised

issued at 17:00 on Friday, September 28, 2012

Edition), 2006

http://www.fdma.go.jp/bn/2012/detail/691.html

5) Japan Meteorological Agency: Monthly Report on15) Ministry of the Environment: Status of Progress with

Earthquakes and Volcanoes in November 2004

Disaster Waste Disposal in Coastal Municipalities in(Disaster Prevention Edition), January 2005

the Three Disaster-afflicted Prefectures, September

6) Headquarters for Earthquake Research Promotion:

7, 2012, Press ReleaseLong-term Evaluation

http://www.env.go.jp/jishin/shori120907.pdf

http://www.jishin.go.jp/main/p_hyoka02.htm

16) Cabinet Office (section in charge of disaster7) Results of surveys by the 2011 Tohoku Earthquake

prevention): Estimate of the Cost of Damage

Tsunami Joint Survey Group (related academic

Resulting from the Great East Japan Earthquake,associations, including the Japan Society of Civil

Press Release, June 24, 2011

Engineers) (see report for October 4, 2012)

http://www.bousai.go.jp/oshirase/h23/110624-1kisya

http://www.coastal.jp/ttjt/.pdf8) Port and Airport Research Institute: Urgent Survey17) Iwaki, H., Korekawa, Y., Gonda, N., Masuda, M., Ito,for 2011 Great East Japan Earthquake and Tsunami

K.: Methods of Estimating the Cost of Damage toDisaster in Ports and Coasts, PARI Technical Note

Stock Resulting from the Great East Japan

No.1231, 2011

Earthquake, November 20119) Geospatial Information Authority of Japan: Area

http://www5.cao.go.jp/keizai3/discussion-paper/dp11

Flooded by the Tsunami (Approximate Figures)

1.pdf(Fifth Report), Press Release, April 18, 201118) Hyogo Prefecture: The Status of Recovery andhttp://www.gsi.go.jp/common/000059939.pdf

Reconstruction Following the Great Hanshin Awaji

10) Geospatial

Information

AuthorityofJapan:

Earthquake, December 2011

Diastrophism Inland and in Marine Areas,

http://web.pref.hyogo.jp/wd33/wd33_000000010.ht

http://www.gsi.go.jp/cais/topic110520-index.html

ml11) Ministry of Land, Infrastructure, Transport and19) Ministry of Land, Infrastructure, Transport andTourism Tohoku Regional Development Bureau:

Tourism: White Paper on Land, Infrastructure,

Subsidence on the Sendai Plain Resulting from theTransport and Tourism in Japan, 2010

Earthquake, Press Release, issued at 14:00 on April

http://www.mlit.go.jp/hakusyo/mlit/h22/index.html

28, 2011

20) Ministry of Land, Infrastructure, Transport andhttp://www.thr.mlit.go.jp/Bumon/kisya/saigai/images/

Tourism: Disaster Information Concerning the Great34888_1.pdf

East Japan Earthquake (No.116), December 3,12) Ministry of Land, Infrastructure, Transport and2012

Tourism Kanto Regional Development Bureau,

http://www.mlit.go.jp/saigai/saigai_110311.html

Japanese Geotechnical Society: Analytical Reporton Liquefaction in the Kanto Area Due to the Great
East Japan Earthquake, 201123

2.2 Response by the National Government

Earthquake was held on April 14, chaired by Makoto(1) Initial Response by the Government

Iokibe (President of the National Defense Academy /As well as establishing the Response Office at theProfessor Emeritus, Kobe University) and with thePrime Minister's Office at 14:50 on March 11,

participation of experts in relevant fields. The Council

immediately

thewas established in accordance with a Cabinet decision

government convened the Emergency Response

after

the

earthquake

struck,taken on April 11, with the objective of conducting

Team (the participants from MLIT were the Director-

wide-ranging discussions concerning a vision for

General of the River Bureau (as it was at the time),

reconstruction, in order to formulate guidelines on

the Vice Commandant for Operations of the Japan

reconstruction, In addition, to ensure that the

Coast Guard, and the Deputy Director-General of theoutcomes of discussions by the Reconstruction

Japan Meteorological Agency).

Design Council would be reflected in guidelines on

At 15:14, as provided for in the Basic Act onreconstruction and other areas of policy, a report

Disaster Control Measures (Act No.223 of 1961), an

entitled Towards Reconstruction was compiled at theEmergency Disaster Response Headquarters headed

12th meeting of the Council on June 25. From thenby the Prime Minister was established for the first time

until November 10, the Council met 13 times, withsince the Act entered into force.

meetings mainly focused on ascertaining the status of

At 15:37, the first meeting of the Emergency

recovery efforts and initiatives aimed at reconstruction.

Disaster Response Headquarters was held and thebasic policy on emergency disaster control measures(3) Reconstruction Headquarters in Response to thewas determined.

Great East Japan Earthquake

At 06:00 on March 12, based on a Cabinet decision,
the

Local

Headquarters

for

ExtremeThe Reconstruction Headquarters in response to

Disasterthe Great East Japan Earthquake, chaired by PrimeManagement (Director: Senior Vice-Minister of the

Minister Naoto Kan and composed of government

Cabinet Office) was established in Miyagi Prefecture.

ministers, was established on June 28, in accordance

Moreover, governmental investigation teams werewith the Basic Act on Reconstruction in response todispatched the same day to Iwate Prefecture and

the Great East Japan Earthquake (Act No.76 of 2011);

Fukushima Prefecture, and Government Local Liaison

the Headquarters and its three local response

Disaster Response Offices were established in eachheadquarters formed a team comprising 131 people.

prefectural office.

The Headquarters took the lead in endeavors to

At the 12th meeting of the Emergency Disastertranslate into reality the recommendations made by

Response Headquarters, which was held on March 17,

the Reconstruction Design Council in response to theit was decided to establish the Headquarters forGreat

Special Measures to Assist the Lives of Disaster

Reconstruction.

East

Japan

Earthquake

inTowards

Victims under the auspices of the Emergency DisasterThe basic policy on initiatives for reconstruction by

Response Headquarters, in light of the fact thatthe government in the aftermath of the Great East

providing livelihood support for those affected by theJapandisaster would become a pressing issue in due course.

approaches

By September 11, a total of 19 meetings of thereconstruction, in order to assist disaster-stricken local

Emergency Disaster Response Headquarters had

authorities

been held.

reconstruction plans) was compiled on August 11,

Earthquake
to
in

the

(whichclarifies

government

theoverallinitiatives

compilation

of

their

for
own

with plans and work schedules being published for(2) Reconstruction Design Council in Response to theeach project.

Great East Japan Earthquake

Moreover,assistancewasprovided

to

local

The first meeting of the Reconstruction Design

authorities in compiling their reconstruction plans, andCouncil in response to the Great East Japanlegislation was introduced concerning such matters as24

special zones for reconstruction.

accreditation of special zones for reconstruction;
allocation of reconstruction subsidies and special(4) Reconstruction Agency

funds for coordinating reconstruction; implementation

Following the December 7 enactment of the Act onof national government projects, and coordination andSpecial Zone for Reconstruction after the Great East

promotion of support for prefectural and municipal

Japan Earthquake (entered into force December 26)

government projects, etc.

and the enactment of the Act on the Establishment of
the Reconstruction Agency on December 9, theRelated legislation:

Reconstruction Agency was established on February

http://www.reconstruction.go.jp/topics/120312relevant

10, 2012. The systems in place hitherto, which had%20legislation%23.pdf

been focused on the Reconstruction Headquarters in
response to the Great East Japan Earthquake and thethree local response headquarters, were transferredto this Agency, which had been established as anorganization to take decisive action in implementing
reconstruction projects without being swayed byexisting precedents, while maintaining close links to
the disaster-afflicted areas, in order to accomplish
reconstruction at the earliest possible juncture. It was
decided that the Agency would be at the heart of thesystem for promoting the smooth, swift execution ofadministrative work related to reconstruction in theaftermath of the Great East Japan Earthquake,
includingtheimplementationofreconstruction

measures using the Third Supplementary Budget of
FY2011 and other funds.
The

Reconstruction

Agencyimplements

thefollowing administrative tasks focused on generalcoordination to assist the Cabinet and administrative
work in relation to the implementation of individual
projects.
(i) Planning and coordination of government measuresrelating to reconstruction
・Formulation of plans such as basic policies; generalcoordination and recommendations concerning eachministry's reconstruction measures・ Management and supervision of reconstruction
projects; integrated submission of reconstruction
budget requests; allocation of budget funds to eachministry

andagency,formulation

of

plans

concerning project implementation, etc.
(ii) Providing support and a single point of contact for
local government bodies
Advice concerning the formulation of reconstructionplans by local authorities affected by the disaster;25

2.3 Responses by the Ministry of Land,
Infrastructure, Transport and Tourism

prefectural governments and the Self-Defense Forces,(1) General Actions

moved into the implementation phase, aimed at

the Tohoku Regional Development Bureau swiftly

At 14:46, immediately after the earthquake struck,

opening up a toothcomb-shaped array of rescue

MLIT established a Major Disaster Management

routesHeadquarters; in addition, the first meeting of theExpressway and National Route 4 to the Sanriku

Emergency Disaster Response Headquarters was

district, which had suffered immense damage due toheld at 15:45 on March 11, and Akihiro Ohata, who

the tsunami. The same day, after completing Step 1,

was Minister of MLIT at that time, announced thewhich was to secure a passage along the Tohoku

following clear objectives: "First, save lives. Then

Expressway and National Route 4 (albeit with somesecure transport routes. Do everything you can thinkdetours), the Bureau moved on to Step 2, focused onof." In addition, meetings of the Emergency Disaster

opening up 11 access routes from the Tohoku

Response Headquarters were held daily until April 1,

Expressway and National Route 4 to major cities on

and weekly thereafter until May 30, with the 49th and

the Pacific coast, a task that had been completed by

final meeting taking place on August 11. Linked to the

March 15.

Tohoku Regional Development Bureau and the
TohokuDistrict

Transport

Bureautofacilitate

accessfromthe

TohokuBy March 18 (a week after the disaster), work wasvia

underway on Step 3, which involved clearing roads

videoconferencing, the Ministry implemented various

running north to south along the Pacific coast, such as

responses while receiving reports on the latest

National Route 45, and apart from the sector where

information from the scene.

work was suspended due to the nuclear power plantMoreover, Parliamentary Vice-Minister Ichimura

accident, 97% of roads were passable, as planned.

was dispatched to Miyagi Prefecture as part of theMembers of NILIM also participated in Operation

governmental investigation team at 18:42 on the day

Toothcomb from the day after the disaster, providingof the disaster, along with staff members from thefull-scale

Ministry headquarters, the Japan Meteorologicalconcerning such matters as judgments about whether

Agency, the Japan Coast Guard, and the Geospatial

or not bridges and other structures could be used.

Information Authority of Japan. This governmental

Operation Toothcomb was able to be completed in theinvestigation

Local

space of a week, thanks to the following: (i) the fact

Headquarters for Extreme Disaster Management atthat it had been possible to prevent fatal damage such

06:00 on March 12 and remained in the area toasconduct further activities. Governmental investigation

measures had already been implemented for 490

teams were dispatched to Iwate Prefecture at 08:52

bridges within the jurisdiction of the Tohoku Regionalon March 12 and to Fukushima Prefecture at 09:18

Development Bureau, in light of the road damage thatthe same day, with Parliamentary Vice-Minister

resulted from the Great Hanshin Awaji Earthquake; (ii)

Tsugawa and a number of Ministry staff among thethe fact that the intensive checks and surveys wasmembers. These governmental investigation teams

carried out and the elimination of road obstacles was

conducted activities as Government Local Liaison

prioritized by clarifying the 16 routes (one was

Disaster Response Offices in both prefectures.

abandoned due to the nuclear power plant accident),

team

was

renamedthebridgecooperation

collapses,andtechnical

becauseguidance

seismic

retrofit

At the same time, at the Tohoku Regional

representing the teeth of the comb, which were theDevelopment Bureau, a decision was taken on Marchroutes from inland areas to the disaster-afflicted areas

11 to adopt a policy of opening up multiple rescue

that needed to be cleared in the immediate aftermathroutes to the Pacific coast, a strategy which theof the disaster; and (iii) the fact that disaster

Ministry dubbed "Operation Toothcomb", as the routes

agreements had been concluded with the construction

formed a pattern similar to the teeth of a comb.

industry in advance, so it was possible to gain the

On

March

12,

workinginpartnershipwithcooperation of the local construction industry in26

initiatives in light of this disasterclearing obstacles from National Routes 6 and 45 incoastal areas (52 teams from local construction
companies and companies from inland areas), as well

References

as the fact that collaboration with the Self-Defense

1) Ministry of Land, Infrastructure, Transport andofTourism: Records of the Great East Japanprefabricated bridges to replace those that had

Earthquake - Response to the Disaster by MLIT,

collapsed along National Route 45.

March 11, 2012

Forcesfacilitatedthepromptinstallation

http://www.mlit.go.jp/saigai/kirokusyu.html

From April 16-17, the Minister of MLIT visited thedisaster-afflicted area for the first time and met withthe three prefectural governors, and the mayors of(2) Dispatch of the Technical Emergency Control

Miyako, Rikuzentakata, Kesennuma, and Ishinomaki

Force (TEC-FORCE)

cities; in addition, he was briefed on the damage andIn response to the Great East Japan Earthquake,

inspected some of the disaster-stricken areas. He

TEC-FORCE* members were immediately dispatchedsubsequently visited the disaster-afflicted areas on ten

tooccasions and promoted measures focused on

Development Bureau from Regional Development

repairing the damage, taking into account the actual

Bureaus across the country, starting on March 11, thesituation on the ground there.

day of the disaster; by the third day after the disaster,thejurisdiction

of

the

TohokuRegional

In light of the government's establishment of thethe number of TEC-FORCE members assembled in

Reconstruction Headquarters following the enactment

the Tohoku region was in excess of 500 (the totalof the Basic Act on Reconstruction in response to thenumberGreat East Japan Earthquake, MLIT established theequivalent of 18,115 man-days by January 31, 2012).

MLIT Reconstruction Headquarters in response to the

The dispatched TEC-FORCE provided support inGreat East Japan Earthquake, headed by the Minister

promptly restoring the functions of local authorities

of MLIT, on June 24, with the aim of facilitating theaffected by the disaster, by such means as conducting

swift, smooth promotion of relevant measures. A

damage surveys.

ofdispatchedpersonnel

reachedthe

In addition, the TEC-FORCE General Headquarters

summary of the meetings of this body is provided

was established in the Tohoku Regional Development1)

below .

Bureau and efforts were made to integrate the chain
Table 2.3.1 Meetings of MLIT Reconstructionof command, in order to facilitate swift coordination of

Headquarters in Response to the Great East Japanthe TEC-FORCE members mobilizing from across the

Earthquake

country and the dispatch of the various types ofDate and Time
June 28
15:20July 27
14:00-

Meeting
Number
1st
Meeting
2nd
Meeting

August 25
3:15 PM-

3rd
Meeting

September 12
3:30 PMNovember 28
3:45 PM2012
March 84th
Meeting
5th
Meeting
6th
Meeting

machinery required for disaster countermeasures.

Content of Meeting

Disaster response helicopters belonging to each

Matters concerning reconstruction fromthe Great East Japan Earthquake
Measures in which the Ministry is
involved, related to the Basic Policy on
Reconstruction from the Great East
Japan Earthquake (draft)
Matters concerning the status of Ministry
initiatives relating to reconstruction
measures in the aftermath of the Great
East Japan Earthquake
The current status of repair work, andinitiatives to deal with major issues
Matters concerning the status of Ministry
initiatives relating to reconstruction
measures in the aftermath of the Great
East Japan Earthquake
Matters concerning responses to theGreat East Japan Earthquake and future

Regional Development Bureau and civilian helicoptersarranged by the Hokkaido Development Bureau wereused for damage surveys across an extensive area,
ranging from the coast of Hokkaido to the Kanto
region; part of the TEC-FORCE group from NILIM
made use of these to go to the disaster-afflicted areas
and gain a broad understanding of the extent of thedisaster.
*TEC-FORCE: This is the abbreviated name of theTechnical Emergency Control Force, which consists ofunits established in the Ministry headquarters, the27National

Institute

for

Land

and

InfrastructureManagement, the Geospatial Information Authority of(4) Other Forms of Support for Recovery Activities

Japan, Local Branch Offices, and the Japan

Variousdisaster

response

vehicles, including

Meteorological Agency. In the event of a large-scale

lighting vehicles, drainage pump trucks, task force

disaster or the risk of such a disaster, the purpose ofvehicles, support vehicles, sprinkler vehicles, bridge

the TEC-FORCE is to provide technical support toinspection vehicles, and vehicles used for gathering

disaster-stricken local government smoothly andinformation, as well as prefabricated bridges were

swiftly,anmobilized on a total of 366 occasions. In addition, aunderstanding of the extent of the disaster, preventing

total of 247 vehicles were mobilized to the Tohoku

the occurrence or escalation of damage, achieving

Regional Development Bureau jurisdiction from otherrecovery in the disaster-afflicted areas as soon as

Regional Development Bureaus.

to

aid

them

in

promptly

gaining

possible, and other emergency disaster control

Moreover, in order to facilitate the flow ofmeasures.

information and communications in the disasterafflicted(3) Dispatch of Disaster Information Liaison Officers

areas,aequipments for us

varietyofcommunicationin disaster response wereStarting immediately after the disaster, Regional

mobilized to support local authorities, with satellite

Development Bureau staff were dispatched to local

communication vehicles (537 unit-days), Ku-SAT

authorities affected by the disaster to serve as(small satellite image transmission equipment; 1,998

Disaster Information Liaison Officers, in order tounit-days), simple image transmission equipment (350

gather information received by the local authority

unit-days), and heli-tele portable stations (2 unit-days)

about the extent of the damage, convey this to thedeployed for a total of 2,887 unit-days.

various Disaster Response Headquarters, including
the one established in the Regional Development(This chapter (2.3) is an edited and revised extract

Bureau, ascertain the support needs of the local

from the cited Reference , concerning those activities

authority, and serve as a point of contact andof various bodies under the auspices of MLIT thatcoordination in relation to such support.

were deemed to have a close relationship with the1)

Initially, the liaison officers dispatched were mainly

activities of NILIM, focusing on details it was felt

office staff from within the jurisdiction of the Tohoku

should be recorded for future reference.)

Regional Development Bureau, but as the response
period became prolonged, support staff from otherRegional Development Bureaus took over and weredispatched to local authorities affected by the disaster.
The liaison officers were initially dispatched to thethree prefectures of Iwate, Miyagi, and Fukushima,
but officers were eventually dispatched to 55
municipalities in 13 prefectures from Hokkaido toTokyo, as well as to the Self-Defense Force (North
Eastern Army Headquarters).
In terms of the number of staff dispatched, thosedispatched to 31 municipalities in four prefectures (theaforementioned

three

prefectures

withinthejurisdiction of the Tohoku Regional Development
Bureau, plus Aomori Prefecture) alone peaked at 96,
and totaled 3,916 man-days from the time the disasteroccurred until June 30.
28

2.4 Response by the National Institute forLand and Infrastructure Management

Roads(1) Initial Response by NILIM and TEC-FORCEOn the day of the disaster, at the request of the
TohokuRegional

Development

Bureau,

NILIM

dispatched six staff members in three teams (therivers team, the bridges team, and the road disastermitigation team), who started work early the following

Dams

morning, on March 12, conducting checks of the

Buildings

Bureau's facilities, accompanying the teams working
to clear the roads, conducting surveys of damage tothe embankments along the Eai and Naruse rivers,
carrying out surveys of disaster-stricken bridges on

Airports

National Route 45, and providing technical support at
the Bureau's Disaster Response Headquarters for thePortscollation and compilation of information on damage toroads.
Even after the dispatch of this team, NILIM

Erosioncontrol

dispatched a total of 262 experts (592 man-days) infields including sewerage systems, rivers, coastlines,

Totalroads, dams, buildings, airports, ports, and erosion
control, at the request of the Tohoku and Kanto
Regional Development Bureau, the various disaster-

In conjunction with the mission as part of the TEC-

stricken prefectures, and a number of bureaus within

FORCE team, staff members conducted surveys of

the Ministry headquarters; after their dispatch, these

the extent of the damage in disaster-afflicted areas

personnel provided support for activities such as thethat remained independent. For example, in the field

repair and restoration of facilities (details of theof construction, NILIM staff worked in partnership withdispatch of each team are summarized in Table Ref.1

the Building Research Institute in conducting surveys

in the reference materials at the end of thisof the damage to wooden buildings, steel structure

publication).

buildings, reinforced concrete buildings, residential

Table 2.4.1 shows the number of staff dispatched inland and ground, and nonstructural elements, andeach field.

surveys of the damage resulting from the tsunami andfire.

Table 2.4.1 Number of NILIM Staff Dispatched in
Each Field
Field
SeweragesystemRiversCoasttsunami inundation
85 people (159 man- ・Confirming safety during roaddays)
clearance
・Diagnosis of the severity ofdamage to bridges and otherstructures, technical guidance
concerning
repairandreinforcement methods
・ Roadside slope diagnosis
and repair
3 people (8 man- ・Soundness checks
days)
44 people (116 man- ・Ascertaining the extent of thedays)damage from the tsunami andearthquake,
earthquakeresistance diagnosis, support
for the establishment ofevacuation shelters
6 people (34 man- ・Ascertaining the extent of thedays)damage to airport facilities
resulting from the tsunami andearthquake
24 people (66 man- ・Ascertaining the extent of thedays)damage to port facilities,
surveys of the coastal
environment
17 people (25 man- ・Ascertaining the extent of thedays)damage in relation tolandslides and mudslides
262 people (592－
man-days)(2) Activities as a Disaster Response Headquarters

Total Number of Staff
Main Activities
Dispatched
58 people (119 man- ・ Surveys of damage todays)
sewage treatment plants andsewage pipes
13 people (36 man- ・ Surveys of the extent ofdays)
earthquake and tsunami
damage to facilities such asembankments
12 people (29 man- ・ Surveys of the extent ofdays)
earthquake and tsunami
damage to facilities such asembankments
・ Ascertaining the extent of

As a result of the earthquake, NILIM's own buildings
in both Tsukuba and Yokosuka sustained prolonged,
severe tremors, and it was expected that damage had
occurred over an extensive area as a result of thisexceedingly rare megaquake. Immediately afterwards,
in response to signs that catastrophic damage had
occurred in various parts of the Pacific coast in the
Tohoku, due to its having been engulfed by anunimaginably vast tsunami, NILIM also established a29

Disaster Response Headquarters. At the Yokosuka

the Headquarters met twice, at 08:45 and 16:00; as

Office, a tsunami warning was issued and staff had towell as sharing information about the extent of the

respond while themselves having to evacuate thedamage on the ground that had become evident frombuilding, which exacerbated the difficulty of conducting

the dispatch of staff members of the weekend, various

activities. In the Tsukuba area (the Asahi andlogistical matters were checked in relation to theTachihara Offices), in addition to a power cut, it wasenvisaged dispatch of numerous TEC-FORCE units toalso impossible to use the emergency electric supply

remote areas in due course, including liaison with theunit for some time at the Asahi Office, so staff were

Headquarters when dispatching staff members to therequired to respond to the disaster amid a situation indisaster-afflicted areas as experts, and arrangements

which it was difficult for them to obtain informationfor emergency vehicle passes. Moreover, discussions

even from television and other mass media.

also took place concerning the system for providing

Moreover, with regard to confirming the safety of

support for disaster recovery through some projects.

staff members, the overloading of telephone lines andFrom March 15, meetings of the Headquarters took

local power cuts made it difficult to communicate via

place at the set time of 09:30 every morning and werelandlines, so it was not possible to confirm the safety

held each day until the 18th. After the third meeting,of all staff members on the day of the disaster. It took

the next one was held on April 25; as well as listening

until the 14th (Monday) to confirm the safety of all 363

to reports on each group's planned activities thereafter

staff members in the Tsukuba district (one employee

and checking on moves by relevant organizations andsustained a contusion to the shoulder as a result of aacademic societies, the framework for liaison during

locker falling over), and until the 15th (Tuesday) until

the forthcoming consecutive holidays was confirmed

the safety of their family members could be confirmed.

and it was decided that information would henceforth

At the first Disaster Response Headquarters

be shared in the regular meetings within the Institute,

meeting, which was convened at 16:00 on the day ofwith meetings of the Headquarters only taking place inthe disaster, it was decided to dispatch experts to thethe event that there was deemed to be a particulardisaster-afflicted areas, as well as gaining a generalneed for one.

understanding of the earthquake based on therecorded results, and reporting on progress withefforts to confirm the safety of staff and their families,
The very same day, six staff members in three teams(the rivers team, the bridges team, and the roaddisaster mitigation team) to the stricken region.
On March 14, at the beginning of the following week,30

Table 2.4.2 Meetings of the NILIM Disaster Response Headquarters
No.
1

2

3

4

5

6

Date
March
11

March
14

March
14

March
15

March
16

March
17

Day
Fri

Mon

Mon

Tues

Wed

Thurs

Time

Main report items
・Overview of the earthquake
16:00 ・Progress in confirming the safety of staff and their families
・Dispatch of experts to the disaster-afflicted areas
・Liaison with the Headquarters in the event that staff are dispatched to disaster-afflictedareas
・Acquiring emergency vehicle passes for use on the expressway
・Response by research institutes (NILIM, Public Works Research Institute, Building
08:45 Research Institute)・Reports on dispatch of TEC-FORCE, etc. to the region and surveys being conducted(including sewerage system, bridges, buildings, erosion control, and disaster mitigation on
roads)
・Extent of the damage to the Institute's laboratory building
・Reports on dispatch of TEC-FORCE, etc. to the region and surveys being conducted(sewerage system, etc.)
17:00
・Matters concerning MLIT's support system for repairing damage to the sewerage system
・Extent of damage to NILIM facilities
・Reports on dispatch of TEC-FORCE, etc. to the region and surveys being conducted(including sewerage system, rivers, roads, buildings,
09:30 erosion control, ports, and airports)
・Extent of damage to NILIM facilities
・Interim budgetary response relating to the disaster
・Reports on dispatch of TEC-FORCE, etc. to the region and surveys being conducted(including sewerage system, rivers, roads, and ports)
09:30 ・Extent of damage to NILIM facilities
・Status of repairs to lifelines linked to NILIM facilities
・Progress in confirming the safety of staff at MLIT and other bodies
・Reports on dispatch of TEC-FORCE, etc. to the region and surveys being conducted(including sewerage system, roads, buildings, and ports)
09:30
・Status of repairs to lifelines linked to NILIM facilities
・Progress with the restoration of modes of transport, etc.

7

March
18

Fri

09:30

・Reports on dispatch of TEC-FORCE, etc. to the region and surveys being conducted(including sewerage system, rivers, roads, buildings,
ports, and erosion control)・Status of repairs to lifelines linked to NILIM facilities
・Progress with the restoration of modes of transport, etc. and reports on other relevant
matters

8

March
23

Wed

09:30

・Reports on dispatch of TEC-FORCE, etc. to the region and surveys being conducted(including sewerage system, rivers, and roads)

9

March
25

Fri

09:30

・Reports on dispatch of TEC-FORCE, etc. to the region and surveys being conducted(including sewerage system, rivers, buildings, and erosion control)

10

March
30

Wed

09:30

・Reports on dispatch of TEC-FORCE, etc. to the region and surveys being conducted(including sewerage system, rivers, roads, buildings,
ports, and erosion control)

11

April
25

16:45

・Reports on dispatch of TEC-FORCE, etc. to the region and surveys being conducted(including sewerage system, rivers, and buildings)
・Moves by relevant organizations and academic societies
・Opening of a website concerning the disaster

Tues

31

Participants
Director of Headquarters andothersNo detailed record
Director of Headquarters
Deputy Directors of Headquarters(2 members)
Headquarters Team (13members)Technical Team (14members)
Director of Headquarters
Deputy Director of Headquarters
Headquarters Team (11members)Technical Team (10members)
Director of Headquarters
Deputy Director of Headquarters
Headquarters Team (14members)Technical Team (9members)
Director of Headquarters
Deputy Director of Headquarters
Headquarters Team (10members)Technical Team (8members)
Director of Headquarters
Deputy Directors of Headquarters(2 members)
Headquarters Team (15members)Technical Team (9members)
Director of Headquarters
Deputy Directors of Headquarters(2 members)
Headquarters Team (13members)Technical Team (8members)
Director of Headquarters, Deputy
Director of Headquarters
Headquarters Team (14members)Technical Team (9members)
Director of Headquarters
Deputy Directors of Headquarters(2 members)
Headquarters Team (6 members)
Technical Team (7 members)
Director of Headquarters
Deputy Directors of Headquarters(2 members)
Headquarters Team (13members)
Technical Team (10 members)
Director of Headquarters
Deputy Directors of Headquarters(2 members), Headquarters
Team (14 members)
Technical Team (11 members)(3) Publication of the Results of Surveys

motion and the tsunami (see Table 2.4.4).

The results of the aforementioned field surveys

Furthermore, in 2012, on March 13 (Nissho Hall,

conducted by NILIM in collaboration with the Building

Tokyo) and March 21 (l-Osaka, Osaka), a seminar

Research Institute were compiled and published inentitled

May 2011 under the title Quick Report of the Field

Earthquake Seminar - What We See Now, One Year

Survey and Research on "The 2011 off the Pacificafter the Disaster was held. This seminar features acoast of Tohoku Earthquake" (the Great East Japan

wide range of reports on initiatives undertaken to date

Earthquake), Technical Note of National Institute forand prospects for the future, including appraisals ofLand

No.636.

the usability of infrastructure such as roads and ports,

Moreover, the final report was compiled and publishedwhich are crucial to lifesaving endeavors and recovery

in March 2012, under the title Report on Field Surveys

activities,

and Subsequent Investigations of Building Damage

emergency repair work, as well as research into such

Following the 2011 off the Pacific coast of Tohoku

matters as the revision of technical standards

Earthquake, Technical Note of National Institute forincluding new disaster prevention measures relating

Land and Infrastructure Management No.674. With

to excess external force and complex natural

regard to the field surveys conducted in collaboration

disasters, in light of the lessons learned from majorwith the Public Works Research Institute, focused on

disasters (see Table 2.4.5).

andInfrastructureManagement

coastal, sewerage, river, dam, and road infrastructure,primarily on the Pacific coast of Hokkaido and the
Tohoku and Kanto regions, the results were compiled
and published in July, under the title Quick Report on
Damage to Infrastructures by the 2011 off the Pacificcoast of Tohoku Earthquake, Technical Note of
National

Institute

for

Land

and

InfrastructureManagement No.646.
In conjunction with the publication of various
materials, on April 26, 2011, NILIM, the Public Works
Research Institute, and the Building Research Instituteheld the Briefing on Surveys Conducted After theGreat East Japan Earthquake at the Hitotsubashi
Memorial Hall in Tokyo; this briefing featured reportson the characteristics of the seismic motion andtsunami, and the extent of the damage to various
facilities and infrastructure, focusing on sewerage,
river, coastal, road, building, port, and airport facilities
and infrastructure (see Table 2.4.3).
In addition, on June 10 the same year, incollaboration with organizations including the Building
Research Institute, NILIM held the Presentation ofSurveys Conducted After the Great East Japan
Earthquake, which featured reports on the results ofsurveys focused on damage to wooden, reinforced
concrete, and steel-frame buildings due to seismic

32

NILIM

and

and

PWRI

technical

Great

guidance

East

Japan

concerningTable 2.4.3 Program for the Seminar on Surveys Conducted After the Great East Japan Earthquake(April 26, 2011, Hitotsubashi Memorial Hall, National Center of Sciences Building)
Organizers: National Institute for Land and Infrastructure Management, Public Works Research Institute, Building Research Institute
Topic

Coordinating Research Department(s)Opening Remarks[Seismic motion]
Attributes of the seismic motion[Tsunami]
Attributes of the tsunami[Ports]Kazuhiro Nishikawa (Director-General, NILIM)
Research Center for Disaster Management, NILIM
International Institute of Seismology and Earthquake
Engineering, Building Research Institute
Coastal and Marine Department, NILIM
International Institute of Seismology and Earthquake
Engineering, Building Research InstitutePort and Harbor Department, NILIM

Extent of the damage to ports from the earthquake andtsunami, and support for their repair[Coast]Extent of the damage to river embankments due to theseismic motion and tsunami[Sewerage system]
Extent of the damage to the sewerage system due to thetsunami and liquefaction, and support for emergency
repair[Roads (bridges)]
Extent of the damage to road bridges and thecharacteristics thereof[Dams]
Overview of the results of interim checks of dams andextent of the main damage[Damage from landslides]
Extent of landslide damage and status of erosion control
infrastructure[Buildings (seismic motion)]
Overview of the damage to buildings due to seismic
motion[Buildings (tsunami)]
Overview of the damage to buildings due to the tsunami[Airports]
Overview of surveys of basic infrastructure at Sendai
AirportShojiro Kataoka(Research Center for Disaster Management,
NILIM)
Kentaro Kumagai(Coastal Disaster Prevention Division, NILIM)
Takashi Nagao(Port Facilities Division, NILIM)

River Department, NILIM

Attributes of the damage to coastal structures and thehinterland due to the tsunami[Rivers]

Presenter

Yoshio Suwa
(Coast Division, NILIM)

River Department, NILIM
Geology and Geotechnical Engineering ResearchGroup, Public Works Research InstituteAtsushi Hattori

Water Quality Control Department, NILIM

Toshihiro Yokota

Materials and Resources Research Group, Public
Works Research Institute(Wastewater System Division, NILIM)

Road Department, NILIM
Center for Advanced Engineering Structural
Assessment and Research, Public Works ResearchInstituteRiver Department, NILIM
Hydraulic Engineering Research Group, Public Works
Research InstituteResearch Center for Disaster Management, NILIM
Erosion and Sediment Control Research Group,
Public Works Research Institute
Building Department, NILIM
Department of Structural Engineering, Building
Research Institute
Building Department, NILIM
Department of Structural Engineering, Building
Research InstituteAirport Department, NILIM(River Department, NILIM)

Jun-ichi Hoshikuma(Center for Advanced Engineering Structural
Assessment and Research, Public Works
Research Institute)
Yoshikazu Yamaguchi(Dam and Appurtenant Structures Research
Team, Public Works Research Institute)
Nobutomo Osanai(Erosion and Sediment Control Division,
NILIM)
Takahiro Tsuchimoto(Evaluation System Division, NILIM)
Yasuo Okuda(Department of Structural Engineering,
Building Research Institute)
Junichi Mizukami(Airport Facilities Division, NILIM)
Taketo Uomoto (Chief Executive, Public
Works Research Institute)

Closing Remarks

33

Table 2.4.4 Program for the Seminar on Surveys Conducted After the Great East
Japan Earthquake(June 10, 2011, Sumai-ru Hall)
Organizers: National Institute for Land and Infrastructure Management, Building ResearchInstitute
Co-organizer: Japan Housing Finance Agency
Topic
Opening Remarks
Activities by MLIT
Activities by the Japan Housing FinanceAgencyCharacteristics of the earthquake andtsunamiCharacteristics of the seismic motion

Characteristics of damage due toseismic motion (wooden buildings)
Characteristics of damage due toseismic motion (reinforced concretebuildings)
Characteristics of damage due toseismic motion (steel-frame buildings)
Characteristics of damage due toseismic motion (residential land andground)Characteristics of damage due toseismic motion (nonstructural elements)
Characteristics of damage due to thetsunami (wooden buildings)
Characteristics of damage due to thetsunami (reinforced concrete buildings)
Characteristics of damage due to thetsunami (steel-frame buildings)

Characteristics of damage due to fire
Closing Remarks

Presenter
Hiroshi Ito
Deputy Chief Executive, Building ResearchInstituteShinji Takami
Planning Officer, Housing Bureau
Takashi Kawada, Technical Information Group
Leader
CS Promotion Department, Japan Housing
Finance Agency
Yushiro Fujii, Senior Research Scientist
International Institute of Seismology and
Earthquake Engineering, Building ResearchInstituteToshihide Kashima, Senior Research Engineer
International Institute of Seismology and
Earthquake Engineering, Building ResearchInstitute
Takahiro Tsuchimoto, Senior Researcher,
Evaluation System Division
Research Center for Land and Construction
Management, NILIM
Hiroshi Fukuyama, Director
Department of Structural Engineering, Building
Research InstituteTakashi Hasegawa, Senior Research Engineer
Department of Structural Engineering, Building
Research Institute
Hiroshi Arai, Senior Researcher
Building Department, NILIM
Yoshio Wakiyama, Senior Research Engineer
Department of Production Engineering, Building
Research InstituteYasuhiro Araki, Research Engineer
Department of Structural Engineering, Building
Research Institute
Hiroto Kato, Senior Research Engineer
Department of Structural Engineering, Building
Research InstituteTadashi Ishihara, Senior Research Engineer
International Institute of Seismology and
Earthquake Engineering, Building ResearchInstituteTatsuya Iwami, Senior Researcher
Research Center for Land and Construction
Management, NILIM
Juntaro Tsuru
Deputy Director-General, NILIM

34

Table 2.4.5 Program for NILIM and PWRI Great East Japan Earthquake Seminar - What We See Now, One Yearafter the Disaster(March 13, 2012, Japan Firefighters Association Hall (Nissho Hall))(March 21, 2012, l-Osaka, (Osaka Labor Center))
Organizers: National Institute for Land and Infrastructure Management, Public Works Research Institute
Topic

Coordinating Research Department(s)Opening Remarks[Seismic motion / liquefaction] Methods of evaluating
design ground motion and liquefaction in light of an
M9 earthquake

Research Center for Disaster Management, NILIM
Geology and Geotechnical Engineering ResearchGroup, Public Works Research InstituteShojiro Kataoka(Research Center for Disaster Management, NILIM)[Ports] The impact on logistics of damage to ports,
and earthquake and tsunami countermeasures

Coastal and Marine Department, NILIM
Port and Harbor Department, NILIM

Shinichi Urabe(Deputy Director-General, NILIM)

River Department, NILIM

Yoshio Suwa, Fuminori Kato
(Coast Division, NILIM)[Coasts / prevention of tsunami-related disasters]
Seawall design techniques and technologies forsupporting the development of tsunami-resistantcommunities[Rivers] Extent of the erosion of river embankments
due to tsunami runup flow and overflow[Rivers] Verification of the effects of measures tocounter the liquefaction of river embankments andrelated challenges[Sewerage systems] Effectiveness of earthquakeproofing techniques for sewerage pipe infrastructure

Kazuhiro Nishikawa (Director-General, NILIM)

River Department, NILIM
Geology and Geotechnical Engineering ResearchGroup, Public Works Research Institute
Water Quality Control Department, NILIM[Sewerage systems] Phased recovery of sewage
treatment plant functions and measures to deal withradioactive material

Water Quality Control Department, NILIM
Materials and Resources Research Group, PWRI

[Roads] Technical standards for road structures withconsideration for securing traffic functions in the eventof an earthquake

Road Department, NILIM
Center for Advanced Engineering Structural
Assessment and Research, Public Works
Research Institute
Geology and Geotechnical Engineering ResearchGroup, Public Works Research Institute[Roads] Road network issues identified from probe
data

Road Department, NILIM[Erosion control] Prediction of sites where
earthquakes are likely to cause landslides andextensive satellite-based survey of landslide scars

Research Center for Disaster Management, NILIM
Erosion and Sediment Control Research Group,
PWRI[Buildings and housing] Technical standards fortsunami evacuation buildings and other buildings[Buildings and housing] Technical support for housing
reconstruction that takes into account regional
characteristics and the local community[Future development of research] Risk and crisis
management for excessive and multiple disasters

Presenter

Building Department, NILIM
Housing Department, NILIM
Research Center for Disaster Management, NILIM
River Department, NILIM

Closing Remarks

35

Atsushi Hattori(River Department, NILIM)
Tetsuya Sasaki(Soil Mechanics and Dynamics Research Team,
Public Works Research Institute)
Wataru Fukatani(Wastewater System Division, NILIM)
Masashi Ogoshi(Wastewater and Sludge Management Division,
NILIM)
Mamoru Suwa
(Recycling Research Team, Public Works ResearchInstitute)Takashi Tamakoshi(Bridge and Structures Division, NILIM)
Jun-ichi Hoshikuma (Center for Advanced
Engineering Structural Assessment and Research,
Public Works Research Institute)
Hidetoshi Kohashi(Construction Technology Research Team, Public
Works Research Institute)
Yukihiro Tsukada, Katsumi Uesaka(Traffic Engineering Division / Road Department,
NILIM)
Masaki Mizuno(Erosion and Sediment Control Division, NILIM)
Toshiya Takeshi(Landslide Research Team, Public Works ResearchInstitute)Atsuo Fukai(Standards and Accreditation System Division, NILIM)
Masashi Mori
(Housing Planning Division, NILIM)
Shigeki Unjoh(Research Center for Disaster Management, NILIM)
Taketo Uomoto (Chief Executive, Public Works
Research Institute)

(4) Collaborative Endeavors Involving Research in
Various Fields (Including the Great East JapanThe objective of this series of workshops was toEarthquake Recovery and Reconstruction Seminars)

share information about what happened during the

NILIM launched a collaborative initiative involving

recent earthquake and approaches to disaster

research in various fields, entitled NILIM Workshops

response in each field at present, based on

on Earthquake and Tsunami Countermeasures:

participation by all those who wished to do, in order toThinking Outside the Box; the first workshop was held

ensure that a wide range of opinions could be heard.

on April 14, 2011 (see Table 2.4.6).

After exchanging opinions regarding the extent of thedamage to various structures and approaches toTable 2.4.6 Workshops on Earthquake and Tsunami Countermeasures
WorkDate
shop No.
1st
April 14
(Thurs)
14:00
～

2nd

3rd

4th

April 18
(Mon)
3:00
PM～

April 20
(Wed)
14:00
～

April 27
(Wed)
14:00
～

5th
May 10Workshop (Tues)
14:00～

Theme, etc.

disaster response during the first workshop, content

Main Content

was solicited from those who wished to engage in thefree exchange of opinions during the second andSharing・ Introduction to theinformation aboutsituation in terms of
the extent of theseismic motion, thedamagetotsunami,seweragestructuresandsystems,
rivers,approaches
tolandslides,
roads,
disaster responsebuildings, the coast,ports, and airports
Exchangeof ・ Introduction to theopinions
situation from theconcerning issues
perspective of remaining(brainstorming)
airports and dams
Theme: Tsunami ・Effects of the tsunami(earthquake)that should be taken into
countermeasuresconsideration in future(1)
disasterprevention
measures
Theme: Tsunami ・Responses to complex,(earthquake)
extensive disasters
countermeasures ・
Liquefaction(2)
countermeasures
Theme: Measuresthroughout the region
todealwith ・Provision of information
complex, extensive
concerningurban
disasters;development
andliquefaction
extensive disasters
countermeasures
Theme:
・
IntroductiontoChallenges facedcomprehensive tsunamiin working toward
relateddisasterrecoveryandprevention measuresreconstruction
・Issues that NILIM should(buildingtackle (short- and longearthquake- andterm issues)
tsunami-resistanttowns and acountry that canwithstandsuchdisasters (hard &soft measures))
Summary・ Outline of damage tomajor facilities andstructures, and progressin dealing with this(general overview)・ Support for thereconstruction of housesin the tsunami-afflicted
area of Banda Aceh

subsequent workshops, including the opinions ofindividuals; the secretariat then coordinated the datesof the workshops and all those who wished toparticipate gave presentations concerning their views
during the next four sessions. A total of 73 people
participated in the workshops, including members ofeach department and division who wished to take part,as well as NILIM's executive officers.
The discussions began with an effort to ascertain
what was meant by the term "beyond expectations",
which had also aroused considerable debate among
the public. The main topics discussed at theworkshops are as follows.
(i) Characteristics that differed from conventional
disasters and matters that could serve as lessons
for the future(ii) Conventional measures that were effective, thosethat were not effective, and new discoveries(iii) Responses to the phenomenon of a multistage
disaster that involves extreme events: regional
characteristics and the question of what must be
protected, and to what extent(iv) Approaches to rehabilitating the disaster-stricken
region and repairing various structures(v) The reality of information sharing in the field in an
emergency(vi) Disaster responses that were implemented
effectively

andthingsthat

exacerbatedthedifficulties(vii) Dealing with hazardous areas(viii) Lifeline malfunctions due to liquefaction and theimpact of this on the lives of local citizens andbusiness continuity of local industry
36

(ix) Hard and soft measures to alleviate suchcommon logistical and back-up systems (including

malfunctions and restore lifelines promptly

TEC-FORCE) were summarized and proposals for(x) Outline of the damage to each type of structure

solutions submitted (see Tables 2.4.7 and 2.4.8).

and establishment of investigative committees, etc.
(xi) Status of emergency measures, emergency
repairs, proper repairs, and reconstruction plans inregard to each type of structure(xii) Current standards regarding infrastructure andfacilities, and approaches to their revision (inparticular, tsunami levels and target performancelevels)Along with these topics, the workshop participantssummarized the issues regarding which NILIM shouldmake a contribution and the Institute's research
objectives, with reference to surveys and studies
aimed at recovery and reconstruction.
Moreover, on May 13, after brainstorming issues
that became evident from the Great East Japan
Earthquake and proposals for solutions to such issues,in light of the discussions and proposals at theseworkshops, the various departments and research
centers at NILIM engaged in an exchange of opinions.
In addition, issues relating to such matters as

37

Table 2.4.7 Issues That Became Evident from the Great East Japan Earthquake and Proposals for Solutions(Common Issues Relating to Logistical and Back-up Systems)
No.

Category

1
2

The mobilization standby time should be minimized, so that the unit can be dispatched without delay.
The TEC-FORCE system

Only limited numbers of vehicles and mobile phones for disaster prevention purposes are available to staff
members, posing an obstacle to the dispatch of experts. The introduction of satellite phones is also required.
Vehicles (minibuses, etc.) for use by staff members, which can accommodate not only the necessary personnel,

4

but also the food, clothing, and equipment that they need, is required.
Strengthening of NILIM's information support system, in order to prevent the dispatched experts from being cut off

5

7

A system is required that takes into account the broader perspective in planning and coordinating the dispatch of
the limited personnel available for dispatch in the event of a large-scale disaster over an extensive area.

3

6

Issue & Proposed Solution

from information once at their destination.
Maintaining a permanent stock of the latest maps for the whole country, in order to ensure that activities in disasterSmoother dispatch ofafflicted areas can be carried out smoothly.

experts

NILIM should designate its emergency vehicles in advance and ensure that it has passes for emergency routes at
all times.
The number of servers and telecommunication lines, which are the key to the volume of information that can betransmitted via the disaster prevention LAN, should be increased. Then it should be enabled to give technical8

guidance and to ascertain the status of the Disaster Response Headquarters in the disaster-afflicted area bymeans of videoconferencing, and to grasp the situation in the disaster-stricken areas through the use of CCTV.
Using emergency negotiated contracts to outsource tasks such as those required in order to carry out recovery

9

and reconstruction without delay.
It is necessary to cultivate experts who can provide technical guidance in the event of disaster, and to implement

10

personnel-related initiatives to secure such experts on an ongoing basis
When a large-scale disaster occurs, in the event of requests for technical support through the dispatch of experts

11Team structure andfocused on an extremely large number of types of infrastructure in various fields, such as roads and rivers, theframework for the dispatch of

Institute should coordinate with other relevant organizations in relation to the expansion of staffing andexpertsorganizations to meet those requests.
A mechanism for gathering information from Ministry headquarters, etc. concerning the technical support required12by the Regional Development Bureau in the disaster-afflicted area, and conveying this information to NILIM (e.g.
dispatch of a liaison officer).

13
14Upgrading of office buildings

Putting in place emergency electric supply unit that can be used in the event of a disaster, even when lifeline

to ensure the continuity offunctions have been lost.

operations

Installation of a well that can provide a source of water in the event of emergency*) Summary as drawn up on May 13, 201138

Table 2.4.8 Research Projects That NILIM Should Tackle in Light of the Great East Japan Earthquake
No.

Category

Research concerning expectations of flood damage due to tsunami and subsidence, and12

Expectations of damage and evaluating the impact ofdamage7

Re-checking areas where there is a danger of landslide and revising the evaluation criteria
thereof
Research into measures to develop a disaster prevention structure in coastal areas of cities

4

6

measures to deal with thisAnalysis of damage to the road network due to the disaster and the economic impact

3

5

Issue

that is tailored to the degree of risk of damage in the event of an earthquake
Prior measures to ensure rapid reconstruction and approaches to plans for recovery andPlans for creating national
land and communities that

Planning

reconstruction

are resistant to disaster,

Approaches to disaster response management

and land use in

Evaluation of the impact on service levels resulting from the severing of the road network,

accordance with thisand consideration of efficient measures to improve functions
Acquisition of data essential

8

to plan formulation

Support for the formulation of disaster prevention plans using flow data

9

Surveys of the extent of the damage to the road structure

10Consideration of seismic design methods for road bridges in relation to megaquakes

11
12

Revision of technical standards, etc.

Surveys of performance requirements for bridges likely to be affected by tsunami
Technical review of the requirements for tsunami evacuation buildings

13

Review of guidelines for preventing roof collapses

14

Responses to long-period ground motion in relation to tall buildings

15

Responses to radioactivity at sewage treatment facilities

16

Deliberations regarding emergency exemptions and relaxation of environmental quality
Responses to the impactof the disaster on

17
18

environmental pollution

21
22
23

Research concerning downstream and processing function recovery measures to minimize
Disaster response at sewage treatment facilities

Energy shortages

Deliberations concerning energy supply and energy conservation on the road network

Systems in the field to support rapid recovery, and securing

Ensuring the soundness of quantity surveying systems used in emergency repair work in

the requisite workforce

the event of a major disaster, and of the local businesses undertaking the work

Consensus building andrisk communication aimed
at recovery andreconstruction

The era of population
decline, an aging population,
and a declining birthrate

Development of models for sustainable dwelling styles in the region in the era of population
decline, an aging population, and a declining birthrate

Risk communication and

Deliberations and surveys concerning risk communication during the reconstruction phaseother issues

Creation of 3D data showing the landscape before the disaster24

Developing landslide observation systems that use remote sensing

25

Rapid collection and26

dissemination of disaster
information

27

standards when conducting disaster recovery
the risk from raw sewage overflow

and energy

1920

Environmental pollution

Ascertaining the extent of
the disaster

Research concerning seismic motion and damage
Using traffic probe data to identify sectors that are passable and travel times through them

Provision of disaster
information

Provision of warnings to vehicles in areas where there is a risk of disaster*) Summary as drawn up on May 13, 2011 (does not correspond to the actual research theme titles subsequently adopted)

39

External experts and others were invited toparticipate in investigative committees established ineach specialist field, with deliberations focusing ontechnical considerations.
As deliberations in each specialist field progressed,
concerns arose that it would become difficult toformulateandimplement

rational,

consistentmeasures; for example, there were worries that if
deliberations in each field were entrusted wholly tothese committees, a situation might arise in which themeasures formulated in those fields would beinconsistent with the given natural and external force
conditions. In order to avoid such a situation, as wellas ensuring that there was a consistent common
awareness

in

each

field,

when

gaininganunderstanding of such matters as the extent of thedamage and the scale of the tsunami and otherexternal forces that caused it, it was deemed vital toshare information when formulating recovery andreconstruction

measures.

Accordingly,

with

the

objective of sharing information about the matters
discussed by each investigative committee, those in
the Tsukuba district launched the Great East Japan
Earthquake Recovery and Reconstruction Seminars(abbreviated title; at the time of the launch, theseminar was entitled The Liaison Conference for
Sharing Information About the Great East Japan
Earthquake) on July 11, 2011; these seminars werechaired by the Executive Director for Research Affairs.
Subsequently, the seminars were held at around onemonth intervals and have taken place 14 times sincethen. Table 2.4.9 provides a summary of the seminarprogram, the information shared, and the main points
discussed.

40

Table 2.4.9 Content of Deliberations at the Great East Japan Earthquake Recovery and Reconstruction Seminars
SeminarNumberDate Held

1stSeminarJuly 11

2nd
SeminarAugust 2

3rdSeminarAugust 26

4th
Seminar

September
29

5thSeminarOctober 19

Main Points Verified

Reports on Main Activities by the Committees

・Reports from each field, moves by the government
・Method of Setting Design Tsunami Water Level, etc.
・Guidelines on tsunami inundation simulations
・Reports from each field, moves by the government
・Liquefaction damage to sewerage infrastructure and river embankments, and construction methods todeal with this・Reports from each field, moves by the government
・Handling of external force from tsunami in river management; embankment structure
・Advantages, disadvantages, and disparities between tsunami envisaged in each field and required
tsunami resilience performance
・Usefulness of the FL method of evaluating liquefaction

・Reports from each field, moves by the government
・Methods of determining wave power (velocity) in the design of tsunami evacuation buildings,
application of reduction rules (2/1.5 times the height)
・Reports from each field, moves by the government
Content of and approaches to the technical standards in the Act on Regional Development for Tsunami
Disaster Mitigation
・Revision of technical standards concerning roads, including guidelines regarding earthworks, andrelevant measures

November 9

7thSeminarDecember 7

・Reports from each field, moves by the government
・Seawalls, methods of setting the design-basis tsunami and crest height, and robust, effective seawall
structures

8th
Seminar2012
January 24

・Reports from each field, moves by the government
・Approaches to methods of setting the standard tsunami, development activity, and draft technicalstandards for tsunami defense facilities
・Approaches to buildings, etc. designated as restricted areas and special restricted areas
・Use of rubble in the development of parks and other social capital

9th
SeminarMarch 8・Matters concerning the content of reports at the Disaster Seminar

March 27

・Reports from each field, moves by the government
・Deliberations concerning robust seawall structures, seawall experiments
・Surveys concerning public housing for disaster victims
・Shake table experiments concerning the effect of measures to counter liquefaction using drain pipes

11thSeminar

May 9

12th
SeminarJune 1

13th
SeminarJuly 13

14th
SeminarOctober 4

Technical Review Committee on Earthquake and Tsunami
Countermeasures Pertaining to Sewerage Systems
Emergency Recommendations concerning River Tsunami
Countermeasures
Technical Review Committee on Liquefaction
Countermeasures
Emergency Investigative Committee on Earthquake
Resistance Measures for River Embankments
Building Structure Standards Committee

・Reports from each field, moves by the government
・Approaches to the design of tsunami evacuation buildings

6th
Seminar

10th
SeminarInvestigative Committee on Measures to Deal with
Radioactive Material in the Sewerage System

・Reports from each field, moves by the government
・Technical bulletin: A Study on Resilient Structures for Coastal Dikes
・Regional block meetings to exchange opinions concerning tsunami inundation assumptions
・Earthquake resistance of sewerage systems, tsunami resistance performance, progress with repairs
・Publication of technical guidelines on the development of parks and green spaces in relation toreconstruction in the aftermath of the Great East Japan Earthquake
・Reports from each field, moves by the government
・Deliberations concerning measures to counter liquefaction on residential land and roads,
measurement of the the effects of measures to counter liquefaction using drain pipes, and other topics
・Reports from each field, moves by the government
・Summary of reports by NILIM, and other topics
・Reports from each field, moves by the government
・Coordination of drafts by the NILIM departments submitting reports, and other topics

41

Building Structure Standards Committee
Bridges Committee (Japan Road Association)
Technical Review Committee on the Creation of Tsunamiresistant Communities
Emergency Investigative Committee on Earthquake
Resistance Measures for River Embankments
Earthworks Committee (Japan Road Association)
Investigative Committee on Tsunami Countermeasures in
Coast Areas
Investigative Committee on Landscapes in the Restoration
and Repair of River and Coastal Structures
Steel Structure Committee / Special Committee on
Surveys of Steel Structures Following the Great East
Japan Earthquake (Japan Society of Civil Engineers)
Investigative Committee on the Development of Parks andGreen Areas in Relation to Reconstruction in the Aftermathof the Great East Japan Earthquake
Committee on the Promotion of Measures to Counter the
Liquefaction of Residential Land
Investigative Committee on Reconstruction Measures inDisaster-afflicted Urban Areas That Suffered Liquefaction
Due to the Great East Japan Earthquake

Disaster Mitigation and Management Committee (Japan
Society of Civil Engineers)

Working Group on Measures to Counter a Nankai TroughMegaquake

The following provides an outline of the main details

risk of their being directly exposed to tsunami damage,that emerged from the discussions at these seminars.

such as some sluice sections, so a structure that

① Setting standards for assumptions about thewould withstand all external forces is not required inheight of the "frequently-occurring tsunami" andthese facilities. In relation to the largest-possiblethe "largest-possible tsunami"

tsunami, deliberations focused primarily on identifying

In almost all fields, an approach was adopted thatwhich areas should be prioritized, such as maintaining

focused on dividing assumptions about tsunami intofunctions, and which parts should be protected in

two levels, wherein it was assumed that theorder to make the restoration of functions easier. On

frequently-occurring tsunami would not give rise to

the other hand, in the case of disaster prevention

damage, while resilient structures should be built toinfrastructure such as seawalls, breakwaters, and river

withstand the largest-possible tsunami, with priority

embankments, it is necessary for the facilities

being given to protecting human life. In terms of thethemselves to have the ability to withstand frequently-

size of this, although there were some differences,

occurring tsunami, and it emerged that there aresuch as in the mode of expression, the approachutterly different approaches concerning the functions

indicated in the Interim Summary by the Central

required of such infrastructure. As a result, a more

Disasterforprofound mutual understanding developed regarding

Technical Investigation on Countermeasures foreach party's design assumptions, such as the fact that

Earthquakes and Tsunami Based on the Lessons

the conditions assumed regarding external forces

Learned from the "2011 off the Pacific coast ofdiffer greatly, and the points that should be borne in

Tohoku Earthquake" was followed (see Figure 2.4.1).

mind when setting external force conditions in each

② Differences between fields in their approach tofield became clear.

Management

Council'sCommittee③ Revised design tsunami height in coastal areas

considering tsunami
In the case of sewerage facilities, the basic premiseand reflection of this in designs

was that other disaster prevention infrastructure suchBringing together information from each field made itasfrequently-occurring

possible to promote analysis of the extent of thetsunami, apart from in areas where there would be adamage in the disaster-stricken coastal regions, theseawalls

would

prevent

Ministries with Responsibility for the Coastline(MLIT, MAFF)

Central Disaster Management Council's Committee
Technical Investigation on Earthquakes andTsunamis (May 28, June 13, 19 and 26)* Interim Summary: Basic Approaches to Future
Tsunami Disaster Prevention Measures (June 26)【Press Release】Method of
Setting Design Tsunami Water
Level, etc. (July 11)
Explanation of Tsunami
Simulations to Municipal
Governments
Technical Review Committee
on the Creation of Tsunamiresistant Communities“Technical Standards for
Tsunami Defense Facilities,
November 28”

Investigative Committee on Tsunami
Countermeasures in Coastal Areas (Held on
April 28, June 27)

Response in Each Type of Structure“Emergency Recommendations concerning River Tsunami Countermeasures, August
22”“Basic Approach to the Development of Parks and Green Spaces in Relation to
Reconstruction in the Aftermath of the Great East Japan Earthquake, October 6”“Policies on Tsunami Countermeasures for Airports, October 21”“Method of Setting the Standard Water Level (Sewage System), Draft TechnicalStandards for Tsunami Defense Facilities, November 9”“Basic Policies for Recovery of Coastal Dikes, November 17”“Interim Guidelines on Requirements for Structural Design of Tsunami Evacuation
Buildings, November 17”“Specifications for Highway Bridges (Revised), February 16, 2012”“Approaches on Sewage Facility Designs taking Anti-Tsunami Measures into Account,
March 8, 2012”“Comprehensive Measures for Earthquake and Tsunami in Ports and Harbors(Report), June 13, 2012”

Figure 2.4.1 Consideration of New Assumptions About Level I and Level II Tsunami and Their Reflection in Each Field (Schematic Chart)42

actual size of the tsunami at each point, and estimates

The seminars featured updates on deliberations byof the scale of the external forces acting on thosethe

Building

Structure

Standards

Committee

points. Moreover, close collaboration facilitated theestablished by NILIM (Chairman: Tetsuo Kubo,

process of rethinking approaches to the design

Professor, Graduate School of Engineering, University

conditions regarding external forces that are requiredof Tokyo, with other members including NILIM Deputy

for tsunami evacuation buildings.

Director Juntaro Tsuru and Building Department

At the ninth seminar, a question and answer

Director Isao Nishiyama; the Committee's tasks

session was held regarding the content of reports toincluded compiling the original draft of the Interim

be given at the NILIM and PWRI Great East Japan

Guidelines on Requirements for Structural Design ofEarthquake Seminar - What We See Now, One Year

Tsunami Evacuation Buildings, Notice Publishedafter the Disaster, which was subsequently held on

November 17, 2011). In addition, there were regular

March 13 and 21, 2012.

briefings on the content of discussions by external

The 13th seminar featured reports concerning thecommittees in which staff members were participating,latest activities relating to research in each field, as

as shown in Table 2.4.10, as well as other moves bywell as reports on the implementation status oftherelevant research activities. It was decided to compile

reconstruction.

this information as a research report that could serve as a point of reference in the event of any similardisasters in future, and opinions were exchanged
concerning the content of this.

43

government

as

a

whole

in

relationtoTable 2.4.10(1) NILIM Staff Involvement in External Committees and Their Recommendations
Name of
Organizer
Relationship to NILIM
Committee, etc.
Ministry of Land, Infrastructure, Transport and Tourism, etc.
Technical Review
Committeeon
Liquefaction
Countermeasures

Main Objectives or
Recommendations

Date

Engineering Affairs
Division, Minister's
Secretariat;
Technology
PolicyDivision,
PolicyBureauWater and Disaster
Management
BureauChairman: Professor
Shoji
Fukuoka,
ResearchandDevelopment
Initiative,
Chuo
University
Japan Institute ofConstruction
Engineering
Chairman: Professor
Ikuo
Towhata,
Graduate School ofEngineering,
University of Tokyo

Shigeki Unjoh, Research
CoordinatorforEarthquake
DisasterPrevention;
ToshiroYokota, Head, Wastewater
System Division(Secretariat)

Outcomes of deliberations
by the Technical Review
Committee on Liquefaction
Countermeasures (August
31, 2011)

2011
May 11, July
12, August 19

Emergency
Recommendations
concerning River Tsunami
Countermeasures (August22, 2011)

2011
July 7, July 28,
August 5

Koichi Fujita, Head, River
Department;
Atsushi
Hattori,
Head,
River
Division

2011
May 11, June
21, August 12,
September 27

Technical Review
Committee
on
Estuary Barrages
and Floodgates inLight of the Great
East
Japan
Earthquake

Water and Disaster
Management
BureauChairman: Professor
Tadashi
Yamada,Chuo University

Investigative
Committeeon
TsunamiCountermeasuresin Coast Areas

Ministries
andagencieswithresponsibility for thecoastline
Chairman: Professor
Masahiko
Isobe,
Graduate School of
Frontier
Science,
University of Tokyo
Water and Disaster
Management
Bureau; City Bureau;
River Department,
NILIM
Chairman:
Shoji
Fukuoka, Professor,
ResearchandDevelopment
Initiative,
Chuo
University

Koichi Fujita, Head, River
Department;
Atsushi
Hattori,
Head,
River
Division; Keiichi Tamura,Research Coordinator for
Earthquake
Engineering(PWRI); Iwao
Sasaki,
SeniorResearcher (PWRI)
YoshioSuwa,
Head,Coast Division

TowardEarthquakeresistance Measures forRiver Embankments (interim
summary; August 12, 2011)
Reporton
FutureEarthquake-resistance
MeasuresforRiver
Embankments in Light of
the Great East Japan
Earthquake (September 27,
2011)
Compilation of the final
report of the technicalreview
committee(September 14, 2011)

The Basic Policies for
Recovery of Coastal Dikes
Damaged by the 2011 Great
East Japan Earthquake andTsunami2011
April 28, June
17, November
15

Technical
ReviewCommittee on the CreationofTsunami-resistantCommunities (January 27,
2012)･ Method of setting thestandard water level･ Technical standards for
specifieddevelopment
activities･ Technical standards fortsunami protection facilities
Landscape Consideration
Manual for the Recovery of
River
and
CoastalProtection
Facilities
Damaged in the Great East2011
November 8,
November 28,
December 9
2012
January 11

River
TsunamiCountermeasures
Committee

Emergency
Investigative
CommitteeonEarthquake
Resistance
Measures for River
Embankments

Technical Review
Committee on theCreationof
Tsunami-resistantCommunities

Investigative
CommitteeonLandscapes in the
Restoration
andRepair of River

Water and Disaster
Management
BureauSecretariat: Yoshio Suwa,
Head, Coast Division

YoshioSuwa,
Head,Coast Division
Kunihiko Amano, Head,River
Environment
Division

44

2011
April 26, May
27, June 22,
August8,September 14

2011
September 1,
September 21,
October
14,
November 11

JapanEarthquake(November 11, 2011)

andCoastal
Structures
Technical Review
CommitteeonEarthquake
andTsunamiCountermeasures
Pertaining
toSewerage
Systems

SewerageandWastewater
Management
Department
Chairman: Professor
Masanori Hamada,
Waseda University

Nobuyuki Horie, Head,
Water Quality Control
Department

Emergency proposals (April
12, 2011); second set of
proposals (May 24); third setof proposals (August 15);
fourth set of proposals(March 8, 2012), Committee
ReportInvestigative
Committee
onMeasures to Dealwith Radioactive
Material in the
Sewerage System

SewerageandWastewater
Management
Department, Japan
SewageWorks
Association
Chairman: Professor
Tetsuya
Kusuda,UniversityofKitakyushu
Japan
Road
Association

Nobuyuki Horie, Head,
Water Quality Control
Department (extraordinary
member); Wastewater and
SludgeManagement
Division(Secretariat),
Yutaka Suzuki, Team
Leader, Materials andResources
Research
Group (PWRI) (member)
Kazuhiro
Nishikawa,Director-General; Shigeki
Unjoh,
Research
CoordinatorforEarthquake
DisasterPrevention;
TakashiTamakoshi, Head, Bridge
and Structures Division
Shigeki Unjoh, Research
CoordinatorforEarthquake
DisasterPrevention;
TakashiTamakoshi, Head, Bridge
and Structures Division
Akio Mizutani, Research
Coordinator for Disaster
Mitigation of Building;MasashiMori,
Head,
Housing
Planning
Division;
Hiroshi
Hasegawa,
Head,
Residential Environment
Planning Division; Ken
Nunota,Housing
Production DivisionInterim Summary by theInvestigative Committee on
Measures to Deal with
Radioactive Material in the
Sewerage
System(November 25, 2011)

Bridges Committee(Permanent)

Earthworks
Committee(Permanent)

Japan
AssociationRoad

Liaison CommitteeonCommunitycentered Housingin
Post-disaster
Reconstruction

Iwate, Miyagi and
Fukushima
Prefectures (and the
Housing Bureau)

Prefectural
Working
Groupson the InspectionofEmergency
Temporary
Housing

Housing Bureau

Joint
LiaisonCommittee
on
Surveys of Public
Housingfor
Disaster Victims

Housing Bureau

Committee on the
PromotionofMeasures
toCity Bureau
Chairman: Professor
Ikuo
Towhata,

Tatsuo Akashi, Head,Urban Planning Division;
Masamiki Ohashi, Senior

45

2011
April 12, May
22-24
July
19,
October
17,
December 15
2012
February 24,
March 222011
June 17, July
25, August 29,
October4,
November 16
2012
May 28Specifications for Highway
Bridges (Revised) (February
16, 2012 (entered into force
April 1, 2012))

2011
May 12, July
27, October 13,
December 14
2012
February 8

Publicationof
FY2012
editionsofHighway
Earthworks: Guidelines on
Measures to Deal with SoftGround and Guidelines on
Retaining Walls
Designs and Production
SystemGuidelinesforCommunity-centered
Housing in Post-disaster
Reconstruction(fromFebruary 2012, for eachprefecture)
Interim Summary of theManual on the Constructionof Emergency Temporary
Housing (May 21, 2012)2011
October27,
November 11
December 14
2012
January 19
2011
September 8,
October4,
December 14

Seminar on Surveys of
Public Housing for Disaster
Victims(March2012),
Guidelines on the Focus of
Projects to Develop Public
Housing for Disaster Victims(entered into force March
31, 2012)
Deliberations
concerningtechnical standards to curbliquefaction damage to2011
December 9.
14-16
2012
January 24-30,
February 10
February 6-14,
March 7-22
2011
September 27,
November 9

2011
November 28
2012
March 26

CountertheLiquefactionofResidential Land

University of Tokyo

Investigative
Committee
on
Reconstruction
Measuresin
Disaster-afflicted
Urban Areas That
Suffered
Liquefaction Dueto the Great East
Japan Earthquake

City Bureau
Chairman: Professor
SusumuYasuda,Tokyo
Denki
University

Deliberations andsurveysconcerningtechniques for thereconstruction ofdisaster-stricken
urban
areas
affected by thetsunamiInvestigative
Committee on theDevelopmentofParks and GreenSpaces in Relation
to Reconstructionin the Aftermath of
the Great East
Japan Earthquake

City Bureau(Conducting surveys ineach field, cooperation ascommittee members, etc.)

City Bureau

Masahiko Matsue, Head,
Landscape and Ecology
Division

CouncilTsunamiSimulations
Airports

Civil Aviation Bureau

Junichi Mizukami, Head,
Airport Facilities Division

Ports and Harbours
Bureau, NILIM
Chairman: Professor
Masahiko
Isobe,
Graduate School of
Frontier
Science,
University of Tokyo

Shinichi Urabe, Deputy
Director-General; Takeshi
Suzuki, Head, Coastal,MarineandDisasterPrevention
Department(Takashi Koizuka, Head,
CoastalandMarineDepartment);
TakashiNagao, Head, Port andHarbor
Department(concurrently Head, Port
Facilities
Division);TakashiNegi,
Head,
CoastalDisasterPrevention Divisionon

Researcher,
Urban
Planning Division; Hiroshi
Arai, Senior Researcher
StructuralStandards
Division; Namihiko Inoue,
SeniorResearcher,Standards
andAccreditation
SystemDivisionfor

Investigative
Committeeon
TsunamiDesignGuidelinesfor
Breakwaters andSeawalls in Ports

46

residential land

Deliberations and Surveys
Aimed at the Reconstructionof Disaster-afflicted Urban
Areas
That
Suffered
Liquefaction Due to the
Great
East
Japan
Earthquake(Guidance(Draft)) (April 2012; City
BureauandNational
Institute for Land andInfrastructure Management)
Deliberations and Surveys
Concerning Techniques forthe
ReconstructionofDisaster-stricken
Urban
Areas Affected by the
Tsunami in the Aftermath of
the Great East Japan
Earthquake (Summary; April
24, 2012)
Basic Approach to theDevelopment of Parks andGreen Spaces in Relation to
ReconstructionintheAftermath of the Great East
Japan Earthquake (interim
report) (October 6, 2011);
Technical
Guidelines
ConcerningtheDevelopment of Parks andGreen Spaces in Relation to
ReconstructionintheAftermath of the Great EastJapan
Earthquake(published March 27, 2012)
Deliberations
concerning
matters
includingthetsunami inundation rangethat is to serve as basic datawhen formulating a plan forthe prompt restoration of
airport functions after an
airport is affected by atsunamiDeliberations on guidelines
for tsunami design

2012
January30,
February 27,
July 9September 11,
October 22
2011
September 27,
November 9
2012
January30,
February 27,
March 27, July
23, October 30

2011
August11,
September 15
November 16
2012
February 21

2012
October2,
March 22
August10,September 24

2011
December 12
2012
January
31,
March 9

Table 2.4.10(2) NILIM Staff Involvement in External Committees and Their Recommendations
Name of
Convening Body
Relationship to NILIM
Main Objectives or
Background to
Committee, etc.
Recommendations
Convening
Dealing with recovery and reconstruction in the disaster-afflicted areas, earthquake countermeasures, etc.
Investigative
Tohoku Regional Atsushi
Hattori, Deliberations concerning the 2011
Committee
on Development
Head, River Division
mechanisms of damage to April 14, May 6,
Technology for the Bureau
embankments and construction May 30, July 29,
Repairofmethodsfortheirrepair; October 7
Embankments
verification of river embankment November 16
Along the Kitakami
structures in relation to tsunami;
and Other Rivers
deliberations concerning checksof disaster-stricken embankments
and flood forecasting standards,
etc. (May 30, 2011: interim report(draft); December 2011: report)
Investigative
Tohoku Regional Yoshio Suwa, Head, Guide to Consideration for the 2011
Environment in Repairs to November 25
Committee on the Development
Coast Division
EstuarineandCoastal 2012
Environment
in Bureau
Infrastructure on the Coast of February
Repairsto9,
Miyagi Prefecture (March)
EstuarineandMarch 7
CoastalInfrastructure
on
the Coast of Miyagi
Prefecture
Investigative
Sendai Research Tomonari
Okada, Deliberations concerning the 2012
Committee
on and Engineering Head, Marine and repair of the breakwater at the February 13 Water
Quality Office for Port and Coast Divisionmouth of Ofunato Port and the March 16
Preservation
Airport,TohokuimpactthereofontheMeasures Relating Regional
environment within the port
to the Repair of the Development
Breakwater at the Bureau
Mouth of Ofunato
Port
Investigative
Kanto
Regional Atsushi
Hattori, Verification of the extent of the 2011
Committee
on Development
Head, River Division
damage to river management April 27, June 1,
Technology for the Bureau
infrastructuresuchas September 14
Repair of Riverembankments;
deliberations
Embankments
concerning
repairmethods
appropriate to the extent of thedamage, river management as
flood season approaches, andeffective approaches to flood
prevention (September 14, 2011;
summaryofdeliberations
concerning
earthquake
countermeasures in relation toriver embankments)
Committee
for Kanto
Regional Atsushi
Hattori, Use of integrated geophysical 2012
Follow-up
Development
Head, River Division
exploration for evaluation of May 24, July 5
Deliberations
on Bureau
embankments
after
repair;River Embankmentdeliberations
concerningtheRebuilding
standard water level for gauging
Techniques
stations
Investigative
Shikoku Regional Yoshio Suwa, Head, Deliberations
concerning 2011
Committee
on Development
Coast Division
earthquake-resistance measures December 9
Earthquake
Bureaurelating to seawalls in areas
Countermeasures
under the Bureau's direct control
AlongDirectlycontrolled Areas of
the Kochi Coast
Tokyo Metropolitan Tokyo Metropolitan Juntaro
Tsuru, Deliberations
concerning 2011
Government
Government, City Deputy
Director- measures to counter liquefaction July 27, October
Investigative
BureauGeneralfocused on buildings such as 18, December 20
Committeeonwood-frame houses
2012
Measuresto(May 21, 2012; interim summary)February
10,
Counter
April 20, July 30

47

Liquefaction
Buildings

ofIwate Prefecture
Expert Committee
on Tsunami andDisasterPrevention
Technology

Iwate Prefecture

Yoshio Suwa, Head,
Coast Division

Presenting proactive fundamental
approaches to tsunami-resilient
urban
and
community
developmentwhenmakingproposals concerning the vision
for reconstruction

Iwate Prefecture
Investigative
Committee on theEnvironment andLandscapes in the
Restoration
andRepair, etc. ofRiver and Coastal
Structures
Investigative
Committeeon
Coastal Tsunami
Countermeasuresin Ibaraki

Iwate Prefecture

Yoshio Suwa, Head,
Coast Division

Basic Approaches Aimed at
ConsiderationfortheEnvironment and Landscapes in
the Restoration and Repair, etc.
of River and Coastal Structures in
Iwate Prefecture (draft) Interim
Summary (March 27, 2012)

Ibaraki Prefecture

Yoshio Suwa, Head,
Coast Division

Project Team on
Damagefrom
TsunamiInundation
andSeismic Motion

Tokushima
Prefecture

Yoshio Suwa, Head,
Coast Division

・Water level of design tsunami
and target embankment height(August 24, 2012)
・ Assumptions
concerning
tsunami inundation (August 24,
2012)
・ Assumptions
concerning
tsunami inundation (October 31,
2012)
・ Deliberations concerning thewater level of design tsunami

Technical Review
Committee on the
Design of Tsunami
Evacuation
Facilities(onroads)

ShizuokaPrefecture

Kazuhiko Mizutani,
Research
Coordinator for Road
Structures

Kochi Prefecture
Investigative
CommitteeonEarthquake
andTsunamiCountermeasures
Pertaining
toSewerage
Systems

Kochi Prefecture

HiroakiResearch
Coordinator
Water
Control

Investigative
Committee
on
Post-disaster
RepairoftheSendai-Tobu Road
Tobu ViaductTechnical Review
Committeeon
TsunamiandEarthquake
Countermeasuresat Tohoku Ports

NEXCO East

Shigeki
Unjoh,
Research
CoordinatorforEarthquake Disaster
Prevention

CoastalDevelopment
Institute
Technology

ShinichiUrabe,
DeputyDirectorGeneral;
Seiji
Matsumoto, Deputy
Director-Generalof

Morita,for
Quality

48

Deliberations concerning plans forthe installation of tsunami
evacuation towers (standard
specifications
anddesignstandards for the tsunami
evacuation towers to be installedon roads on September 2012)
Assumptions concerning damage
toseweragefacilities,in
preparation for a Nankai Troughmegaquake;promotionofearthquake
andtsunamicountermeasures(earthquake
andtsunamiguidelines
concerning the sewerage system
are due to be formulated at theend of FY2012)
Damage analysis and estimates;deliberations concerning repair
methods

Technical review of policies for the
repair of port facilities affected by
the disaster (September 2011,
Technical Review Policy on
Repair of Breakwaters andWharves)

2011
April 22, May 8,
May 23, July 4,
August9,September
5,
October 15
2012
January
23,
October 26
2011
November
17,
December 19
2012
January27,
February
23,
September 14

2011
December 26
2012
February
15,
March
30,
August 24
2011
December 17
2012
April
8,
September
2,
October 29
2012
July 30, August
29, September
27

2012
October 5

2011
May 11, August
25, December 2

2011
April 30, June 9,
September 26

Investigative
Committee on the
Basic Plan for
TsunamiCountermeasuresfor
SewageTreatment Plants
in Yokosuka
Specialist
Investigative
Committee on the
Revisionof
Policieson
Earthquakeresistance
Measuresfor
Sewerage
Facilities

Japan Institute of
Wastewater
Engineering
Technology(Yokosuka)

ToshiroYokota,Head, Wastewater
System DivisionJapan
SewageWorks Association

Nobuyuki
Horie,
Head, Water Quality
Control Department;
HiroakiMorita,Research
Coordinator
for
Water
Quality
Control;ToshiroYokota,Head,
Wastewater System
Division;
IchiroHarada,Head,
WastewaterandSludge Management
Division

49

Numerical analysis simulation
techniques
forforecastingtsunami damage to sewage
treatment plants; deliberations
concerning
tsunamicountermeasures for sewage
treatment plants in the city of
Yokosuka
Deliberations concerning therevision of relevant existing
manuals and guidelines in
response to the report compiledbytheTechnical
ReviewCommittee on Earthquake andTsunamiCountermeasures
Pertaining to Sewerage Systems

2012
January 19. April
26, July 19

2012
June 26

Table 2.4.10(3) NILIM Staff Involvement in External Committees and Their Recommendations
Name of
Convening Body
Committee, etc.
Academic Society, etc.

Relationship to NILIM

Main Objectives or
Recommendations

Background toConvening

Investigative
Committee
on
Evaluation
of
Wave
Force
Inflicted on Bridges
by Tsunami

Japan Society of
Civil Engineers
Chairman:Professor Kyuichi
Maruyama,
Nagaoka
UniversityofTechnology
Japan Society of
Civil Engineers
Chairman: Atsuo
Ogawa,
West
NipponExpressway
Engineering
Kansai Co., Ltd.
Japan Society of
Civil Engineers

TakashiTamakoshi, Head,
BridgeandStructures Division

Investigative
Committee
on
Evaluation of Wave Force Inflicted
on Bridges by Tsunami: Interim
Report (June 26, 2012)2011
August9,
November 4
2012
February 14, May
18

TakashiTamakoshi, Head,
BridgeandStructures Division

Extent of the Damage to Steelframe Structures and the Analysis
Thereof: Report of the Special
Committee on Surveys of Steel
Structures Following the Great
East Japan Earthquake

2011
November 25
2012
January 27

NozomuMori,
Research
CoordinatorforConstruction
Management

2011
December 21, 22
2012
January:
Interviews

Urayasu
City
Technical Review
Committee
onMeasurestoCounter
Liquefaction

Japan Society of
Civil
Engineers;
Urayasu Cityt

Technical Review
Committee on the
Feasibilityof
MeasurestoCounter
Liquefaction

Japan Society of
Civil
Engineers;
Urayasu Cityt

Hiroshi Arai, SeniorResearcher
StructuralStandards
Division;
ToshiroYokota,Head,
Wastewater
System Division
Hiroshi Arai, SeniorResearcher
StructuralStandards DivisionInterim Briefing (2011
December 14)
Symposium:Strengthening
Disaster Response Management
Ability: What Was Learned fromthe Great East Japan Earthquake(scheduled for November 2012)
Citizens' Briefing on the Technical
Review of Measures to Counter
Liquefaction(December18,2011); March 2012: publication of
the Report on the Technical
Review of Measures to Counter
Liquefaction in Urayasu City

2012
June 25, August 24

Subcommittee on
Research
into
Performancebased
Seismic
Design Techniquesfor
Bridges;Working Group on
AnalysisofDamageto
Bridges Due to theGreat East Japan
Earthquake
Great East Japan
Earthquake
DamageSurveyCommittee

Earthquake
Engineering
Committee, Japan
Society of Civil
Engineers

Shojiro Kataoka,
Senior Researcher,
Earthquake
DisasterPrevention Division

Dewatering methods and latticeshaped ground improvement;
evaluation of the liquefaction
prevention and reduction effects
of individual methods and thebusiness risks thereof, anddeliberations
concerningthefeasibility of an integrated
program of measures to counterliquefaction in urban areas,
focused on residential land,roads, and other public facilities
Activity Report of the Working
Group on Analysis of Damage to
Bridges Due to the Great East
Japan Earthquake (July 26,2012); Report of the Working
Group on Analysis of Damage to
Bridges Due to the Great East
Japan Earthquake

Japan Society of
ErosionControlEngineering

Nobutomo Osanai,Head, Erosion and
Sediment Control
Division
Atsushi Okamoto,
Head, Erosion and
Sediment Control

Deliberations concerning surveys
and measures aimed at the
reduction of landslides due toearthquakes in future, based on
fact-finding surveys

2011
December 2
2012
January 17
Specialsymposium

Steel
Structure
Committee/
Special Committee
on Surveys of
Steel
Structures
FollowingtheGreat East Japan
Earthquake
Disaster Mitigationand Management
Committee

50

2011
July
22,
September 12
October
17,
November 28

2011
November
28,
September
29,
December 8
2012
January 25, March
16, April 25

DivisionCommittee
on
SurveysofPrestressed
Concrete
Structures
FollowingtheGreat East Japan
Earthquake;
Earthquake Survey
Working GroupSpecial Committee
on the Great East
Japan Earthquake
Subcommittee on
Materials
Production
andUse
Special Committee
on the Great East
Japan Earthquake
Subcommittee on
Structural Design

Japan Prestressed
Concrete
Engineering
Association

Shojiro Kataoka,
Senior Researcher,
Earthquake
DisasterPrevention Division

Report of the Committee on
Surveys of Prestressed Concrete
Structures Following the Great
East
Japan
Earthquake(December 21, 2011); Report on
Damage Surveys of Prestressed
Concrete Structures Following theGreat East Japan Earthquake

Japan
Concrete
Institute

Hiroyuki Tanano,
Research
Coordinatorfor
Quality Control of
Building

Interim Report by the Special
Committee on the Great East
Japan Earthquake (July 5, 2012;
JCI Annual Convention 2012
(Hiroshima))

Japan
Concrete
InstituteInterim Report by the Special
Committee on the Great East
Japan Earthquake (July 5, 2012;
JCI Annual Convention 2012
(Hiroshima))

Committee
on
Verification
andEvaluationofAcademic Society
Proposals

Japanese
GeotechnicalSociety

Yusuke Fukunaga,
Senior Researcher,Port
Facilities
Division; Toshikazu
Kabeyasawa,Researcher,Standards
andAccreditation
System Division
ToshiroYokota,Head, Wastewater
System Division

Committeeon
Research
into
TsunamiCountermeasuresand Guidelines for
These

Japan Associationfor
Earthquake
Engineering

Yasuo
Okuda,
Research
CoordinatorforAdvanced Building
Technology;
Masahiro Kaneko,
Head, Earthquake
DisasterPrevention Division

51

Issues and Measures Concerning
GroundDamageDuetoEarthquakes(Lessons
andRecommendations from the Great
East Japan Earthquake) (June2011)
Seminar: Lessons from Tsunami
Damage Due to the Great East
Japan Earthquake (October 21,
2011)(discussions via email)2011
April 22, May 6,
May 13, May 31,
June 13, June 26,
July 12, October
12, November 30
2011
August24,
December 27
2012
March 16, August29

2.5 Other Relevant Developments

recommendations

concerning

recoveryandTable 2.5.1 and 2.5.2 provide a summary of various

reconstruction that emerged as the outcomes thereof.

government-oriented conferences and committees

A number of the activities shown in Table 2.5.2 that

established under the auspices of academic societies

were conducted under the auspices of academic

and organizations other than the aforementioned

societies were implemented with participation andactivities by the government, MLIT, and NILIM; incooperation from NILIM as well.

addition,

thesetablessummarize

theTable 2.5.1 Conferences Established by the Government and Their Recommendations Concerning Recovery and Reconstruction
Start of
Deliberations
Name
Main Members
Date
Recommendations, etc.
and Number of
Meetings
March 11 (3 times),
March 12Emergency
Disaster(3 times), March 13
Response(twice)Headquarters for the
March 11 March 14, March 15,
2011 Great East Japan
September 11,
March 16
Earthquake
2011;
19
March 17, March 21,
http://www.bousai.go.jp/
meetings
March 31
1info/higashinihon_taisa
April 11, May 6, May
ku/index.html
20,
August26,
September 11
April 27, October 11, Interim Policy on Initiatives Aimed at Enhancing andJanuary
26,
CentralDisaster Chairman:
Prime
December 27
Strengthening Disaster Prevention Measures; March 29,
2001 onwards;
Management Council
Minister2012
2012
31 meetings
March 29, September 6 http://www.bousai.go.jp/chubou/30/30_siryo2.pdf
Basic Approaches to Future Tsunami Disaster Prevention
Measures (Interim Summary; June 26, 2011)
Committee
forhttp://www.bousai.go.jp/jishin/chubou/higashinihon/tyuuka
Technical Investigation Chairman:
Yoshiakin.pdf
on Countermeasures Kawata; Vice-chairman:
May 28, June 13, June Recommendations Arising from the Interim Summary:for Earthquakes and Katsuyuki
Abe;19, June 26, July 10, Basic Approaches to Future Tsunami Disaster Prevention
Tsunami Based on the members
including May
28
July 31, August 16, Measures (June 26, 2011)
Lessons Learned from Masahiko
Isobe, September 28,
August 25, September http://www.bousai.go.jp/jishin/chubou/higashinihon/teigen.
the "2011 off the Pacific Fumihiko
Imamura, 2011;12
10, September 17, pdf
coastof
Tohoku Makoto
Okamura, meetings
September
24, Committee
forTechnical
Investigationon
Earthquake"
Kunihiko Shimazaki,
September 28
Countermeasures for Earthquakes and Tsunami Basedhttp://www.bousai.go.jp/ Shigeo
Takahashion the Lessons Learned from the "2011 off the Pacificjishin/chubou/higashinih (PARI)
coast of Tohoku Earthquake" (September 28, 2011)
on/index_higashi.html
http://www.bousai.go.jp/jishin/chubou/higashinihon/houko
ku.pdf
Interim Report of the Council on Disaster
October 28, November
Countermeasures Promotion, March 7, 2012
Council on Disaster
28, December 7
http://www.bousai.go.jp/chubou/suishinkaigi/chukan_hont
Countermeasures
October
28, 2012
ai.pdf;Promotion2011 - June 28, February 1, February
Final Report of the Council on Disaster Countermeasures
http://www.bousai.go.jp/
2011;
13 16, March 7, April 18,
Promotion, July 31, 2012
chubou/suishinkaigi/ind
meetings
April 26, May 17, June
http://www.bousai.go.jp/chubou/suishinkaigi/saishuu_hont
ex.html
7, June 28, July 19,
ai.pdfJuly 31
Council on Disaster
Countermeasures
Promotion:
Working
Group on Measures to
Deal with a Nankai
Trough Megaquake
http://www.bousai.go.jp/
jishin/chubou/taisaku_nankaitrough/index.html

Chairman:
Yoshiaki
Kawata; Vice-chairman:
AtsushiTanaka;members
including
Katsuyuki
Abe,Fumihiko
Imamura,Nobuo Fukuwa

From April 20,
2012;8
meetings

2012
April 20, May 28, June
8, June 27, July 17,
August 8, August 22,
September 4, October
1052Interim Report Concerning Measures to Deal with aNankai Trough Megaquake, July 19, 2012
http://www.bousai.go.jp/jishin/chubou/taisaku_nankaitroug
h/pdf/20120719_chuukan.pdf
Working Group on Measures to Deal with a Nankai
Trough Megaquake (First Report), August 29, 2012
http://www.bousai.go.jp/jishin/chubou/taisaku_nankaitroug
h/pdf/20120829_higai.pdf

Committee
forModeling a Nankai
Trough Megaquake
http://www.bousai.go.jp/jishin/chubou/nan
kai_trough/nankai_tr
ough_top.html

Chairman:Abe;
including
Imamura,Okamura,OkamuraKatsuyuki
members
Fumihiko
MakotoYukinobu

2011
From August 28;
26 meetings to
dateAugust 28, October 3,
October 25, November
15, November 24,
December
12,
December 27
2012
January 17, January
30,
February
13,
February 20, March 1,
March 19, March 27,
March 31, April 27, May
17, May 31, June 19,
July 2, July 17, August
1, August 9, August 17,
September 24, October
11
2012
April 25, May 25, June
6, June 18, July 10,
August 6, September 6,
October 16

Committee for Modeling a Nankai Trough Megaquake
Interim Summary, December 27, 2011
http://www.bousai.go.jp/jishin/chubou/nankai_trough/chu
kan_matome.pdf

Working Group on
Measures to Dealwith an Earthquake
Directly under the
Capital City
http://www.bousai.go.
jp/jishin/chubou/taisa
ku_shutochokka/inde
x.htmlChairman:
HiroyaMasuda;Vicechairman:
Hiroaki
Yoshii;members:
Katsuyuki Abe, Miho
Ohara;
ItsukiNakabayashi; Haruo
Hayashi;
Yoshiaki
Hisada2012
From April 25; 8
meetings to dateCommittee
forModelingan
Earthquake Directly
under the Capital City
http://www.bousai.go.
jp/jishin/chubou/shuto_chokka/index.html

Chairman: Katsuyuki
Abe;members
including
Fumihiko
Imamura,Tomotaka
Iwata, Nobuo Fukuwa,
Takashi Furumura

2012
From May 11; 8
meetings to date2012
May 11, June 8, June
29, July 9, July 24,
August 7, September
20, October 3

Chairman:AtsushiTanaka;members
including
Katsuyuki
Abe, Masahiko Isobe,
Fumihiko
Imamura,Toshitaka Katada

From December
24, 2010; 9
meetings to date2010
December 24
2012
January 23, February
29, March 26, April 26,
May 23, June 7, June
13, June 28(The objective was to consider the model of anearthquake directly under the capital city as envisaged
in 2005 by the Central Disaster Management Council,
and examine the distribution of seismic intensity andtsunami height using a model for the largest-possible
megaquake occurring along the Sagami Trough, taking
into account all possibilities based on the latest scientificknowledge available at present)
Working Group on Tsunami Evacuation Measures, July18, 2012
http://www.bousai.go.jp/jishin/chubou/taisaku_tsunami/
wg_20120718/report.pdf

Working Group on
Tsunami Evacuation
Measures (Working
Group on Tsunami
Disaster Prevention)
http://www.bousai.go.
jp/jishin/chubou/taisa
ku_tsunami/index.ht
mlCouncil on Measures
to Counter a Nankai
Trough Megaquake

Masaharu Nakagawa,
Minister of State forDisaster Management;
Yasuo
Harada,Director-Generalfor
Policy Planning; Katsuki
Sasaki, Deputy Director
General for Disaster
Management, Minister's
Secretariat,
CabinetOffice; representativesof 136 organizations,
including government
ministries
andagencies, Local Branch
Offices, and designatedpublic institutions (2ndmeeting:
119organizations)2012
From June 4; 2
meetings

24
June 4, August 10

53

Committee for Modeling a Nankai Trough Megaquake(Second Report), August 29, 2012
http://www.bousai.go.jp/jishin/chubou/nankai_trough/pdf/20120829_2nd_report01.pdf

Interim Report on Measures to Deal with an Earthquake
Directly under the Capital City, July 19, 2012
http://www.bousai.go.jp/jishin/chubou/taisaku_shutocho
kka/pdf/20120719_chuukan.pdf(Consisting of representatives of various government
ministries and agencies, Local Branch Offices, relevant
local government bodies, and designated public
institutions, this Council was convened due to therecognition that the establishment of a forum to bring
together a wide range of bodies from both the public
and private sectors and the building of relationships thatwill endure in both times of peace and in emergencies
were pressing issues)

Table 2.5.2 Committees Established by Academic Societies and Their Recommendations
Name of Committee, etc.

Main Objectives or Recommendations

Science Council of Japan
Committee on Measures in Response to theGreat East Japan Earthquake
1st meeting (March 24, 2011) - 24th Meeting(September 14, 2011)
Science Council of Japan
Subcommittee on a Grand Design for the
Reconstruction of the Disaster-afflicted Areas
1st meeting - 7th meeting (April 20, May 9, May
30
June 20, July 28, August 6, September 14)

Committee on Supporting Reconstruction after
the Great East Japan Earthquake
1st meeting (October 28, 2011) onwards(2012 February 20, March 16, April 3 onwards(ongoing))
Committee on Supporting Reconstruction after
the Great East Japan Earthquake
Sub-Committee on Building Disaster-Resilient
Communities
1st meeting (December 2, 2011) onwards(2012 January 13, February 3, March 2,
October 5 onwards (ongoing))
among others

March 25, 2011 First Emergency Recommendation in Response to the Great East Japan Earthquake
April 4 Second Emergency Recommendation: Regarding the necessity of the investigation of radiationlevels after the accident of the Fukushima Daiichi Nuclear Power Plant
April 5 Third Emergency Recommendation: For the relief of victims of the Great East Japan
Earthquake and the recovery of the disaster-stricken areas
April 5 Fourth Emergency Recommendation: Urgent proposal related to measures for earthquake
disaster waste and prevention of environmental impact
April 13 Fifth Emergency Recommendation: Utilization of robot technology for the accident of the
Fukushima Daiichi Nuclear Power Plant
April 15 Sixth Emergency Recommendation: Perspective of gender equality with regard to relief,
support, and restoration
April 20 Establishment of the Subcommittee on a Grand Design for the Reconstruction of the Disasterafflicted Areas, 1st meeting (Subcommittee on Energy Policy Options and joint session)
June 8 Recommendation: Reconstruction of the disaster-stricken areas of the Great East Japan
Earthquake – Reconstruction goals and seven principles August 3 Seventh Emergency Recommendation: Scientific Survey and Analysis of Movement ofRadioactive Substances over a Wide Area
September 21 Recommendation: Employment support and industrial regeneration support inreconstruction from the Great East Japan Earthquake
September 27 Recommendation: Protecting children from the Great East Japan Earthquake and thesubsequent nuclear power plant accident
September 30 Recommendation: Reconstruction of a new generation fisheries industry after the Great
East Japan Earthquake
September 30 Recommendation: Reconstruction of the disaster-stricken areas of the Great
East Japan Earthquake - Reconstruction goals and seven principles (2nd recommendations) –April 9, 2012 Recommendation by the Committee on Supporting Reconstruction after the Great East
Japan Earthquake: Recommendations from Science Council of Japan (SCJ) - with Confident Steps
towards Reconstruction April 9 Recommendation by the Sub-Committee on Building Disaster-Resilient Communities,
Committee on Supporting Reconstruction after the Great East Japan Earthquake: Building Tsunamiproof Communities – Showing How Tohoku Reconstruction Makes Use of Nature –April 9 Recommendation by the Sub-Committee on the Promotion of Industry and Employment,
Committee on Supporting Reconstruction after the Great East Japan Earthquake: Supporting JobSeekers and Establishing Reconstruction Non-profits in Disaster-Stricken Areas- Towards the
Promotion of Industry and Employment to Support Victims in Disaster-Stricken Areas April 9 Recommendation by the Sub-Committee on Counter-measures for Radiation, Committee on
Supporting Reconstruction after the Great East Japan Earthquake: Toward Making a New Step
Forward in Radiation Measures - Taking Actions based on Fact-based Scientific Research June 22 Establishment of the Sub-Committee on Building Resilience to Disasters
June 22 Establishment of the Sub-Committee on Supporting Reconstruction in FukushimaJune 22 Establishment of the Sub-Committee on Energy Supply Problems

Collaborative Endeavors by Academic Societies
Society of Heating, Air-Conditioning andSanitary Engineers of Japan, Japanese
Geotechnical Society, Japan Society of Civil
Engineers, Architectural Institute of Japan,
Japan Concrete Institute, Japanese Institute ofLandscape Architecture, City Planning Instituteof Japan
Science Council of Japan, Japan Society of Civil
Engineers, and 20 other academic societies
Liaison Council of Academic Societies andAssociations for a Comprehensive Response to
the Great East Japan Earthquake; initiative
involving 30 academic societies

April 26, 2011
Joint recommendation by the presidents of the seven academic societies concerning reconstruction in
the aftermath of the Great East Japan Earthquake

May 27, 2011
Basic Policy for Protecting the Lives of the People and National Land from Megaquakes and Massive
TsunamiMay 10, 2012 Joint statement by the 30 academic societies: Toward the Rethinking of Policies on
National Land and Disaster Prevention and Mitigation - Protecting the Lives of the People and National
Land from Major Disasters

54Name of Committee, etc.

Main Objectives or Recommendations

Japan Society of Civil Engineers
Great East Japan Earthquake Special
Committee

Organization of sessions for the dissemination of proposals on specific themes: Regional Disaster
Preparedness and Response Planning Committee; Tsunami Disaster Management Committee; Soil
Liquefaction Committee; Civil Engineering Technology for Nuclear Safety Committee; PostEarthquake Recovery & Reconstruction Committee; Reconstruction EngineeringTechnology
Committee; Creative & Innovative Reconstruction-PI System Committee; Disaster Mitigation andManagement Committee; Committee on ICT-Based Natural Disaster Risk Management andResilience Development; Radioactive Waste Countermeasure Civil Engineering Committee
Special activities: Social Safety Committee, Tsunami Damage Estimation and Risk Reduction
Committee, JSCE Regional Chapter Group on Reconstruction Design for a Disaster Resilient, Safe
Land Structure
June 2012 Report of the Tsunami Damage Estimation and Risk Reduction Committee
July 20 Interim Summary of the Social Safety Committee: Restoring Trust in Engineers
August 8 Creative & Innovative Reconstruction-PI System Committee: Final Report on Guidelines for
Creative and Innovative Reconstruction

Architectural Institute of Japan
Headquarters for Supporting Surveys andReconstruction Following the Great East
Japan Earthquake: Research and Proposals
Subcommittee
Japanese Geotechnical Society

September 26, 2011 Returning to the Basic Purpose of Architecture: Regeneration and Innovation of
a Place for Living - in Light of the Great East Japan Earthquake (First Recommendations)

FY2011 Committee on Verification and
Evaluation of Academic Society Proposals

August 8, 2011 Issues Relating to Ground Damage in the Event of an Earthquake and RelevantCountermeasures
Lessons and Proposals in the Aftermath of the 2011 Great East Japan Earthquake (First) (Toshiro
Yokota, Head, Wastewater System Division worked in partnership with the committee)
August 3, 2012 Issues Relating to Ground Damage in the Event of an Earthquake and RelevantCountermeasures
Lessons and Proposals in the Aftermath of the 2011 Great East Japan Earthquake (Second)

Japan Association for Earthquake Engineering
Symposium of 6 academic societies

Special Research Committee on Responses
to Extensive System Damage

March 1-4, 2012
International Symposium on Engineering Lessons Learned from the Giant Earthquake - One Year
After the 2011 Great East Japan Earthquake Sponsors: Ministry of Land, Infrastructure, Transport and Tourism, NILIM (Shigeki Unjoh, Research
Coordinator for Earthquake Disaster Prevention, participated in the organizing committee for the
symposium)
May 24, 2012
Proposals for Earthquake Damage Mitigation and Reconstruction: In Light of the Great East Japan
Earthquake

Japanese Institute of Landscape Architecture
Investigative Committee on Supporting
Reconstruction after the Great East Japan
Earthquake

May 21, 2011 Recommendations for Reconstruction Support in the Aftermath of the Great East
Japan Earthquake: Post-disaster Reconstruction Through Landscape Regeneration
May 15, 2012 Publication of Scenes of Reconstruction: A Concept Book for Supporting
Reconstruction Through Landscape Generation

55

3. Initiatives Focused on Recovery and Reconstruction Following the Great
East Japan Earthquake
3.1 Initiatives by the National Institute forLand and Infrastructure Management
Focused on Recovery and Reconstruction

local authorities, it includes matters relating to the
support provided as part of the external committees inwhich NILIM members participated and the proposals

As a member of bodies including TEC-FORCE,

that they made, which are summarized in Table 2.4.10.

NILIM has conducted emergency damage studies anddamage analysis focused on facilities within NILIM’s
jurisdiction, working in partnership with various
relevant organizations, starting in the immediate
aftermath of the Great East Japan Earthquake inMarch 2011. In addition, as befits its role as a research
instituteaffiliateddeliberations

and

to

MLIT,

made

it

has

conducted

proposalsconcerning

emergency response measures, as well as providing
technical support in relation to legislation and therevision of technical standards, and technical support
at sites where construction and repair were taking
place.
This chapter provides a summary of the support
measures implemented in relation to post-earthquake
recovery and reconstruction measures in various fields
including erosion control, sewerage systems, rivers,
water resources, coastlines, roads, ports, airports,buildings, houses, cities, parks and other green areas,
IT and information, and environmental technology.
In addition, with regard to technical support for MLIT
headquarters, its Regional Development Bureaus, and56

3.2. Evaluation and Analysis of Seismic
Force and Action
3.2.1. Ground Motion~4 ~10 ~20 ~40 ~70 ~120 120~Spectrum Intensity (SI) [cm/s]

KSN (Kesennuma)
PGA = 607 [cm/s2]
SI = 90 [cm/s]
JMAISI = 6.2

The 2011 off the Pacific coast of Tohoku

OSK (Ohsaki)
PGA = 484 [cm/s2]
SI = 105 [cm/s]
JMAISI = 6.1

Earthquake(hereinafter referred to as the Tohoku
Earthquake) of which source region, is approximately
450 km long and 200 km wide, ruptured from

WKY (Wakuya)
PGA = 523 [cm/s2]
SI = 84 [cm/s]
JMAISI = 5.9

offSanriku to off Ibaraki Prefecture and became an event

NRS (Naruse)
PGA = 659 [cm/s2]
SI = 84 [cm/s]
JMAISI = 6.0

1)

with the largest moment magnitude, Mw 9.0 , in1)

Japan’s observation history. Figure-3.2.1.1

shows

SND (Sendai)
PGA = 861 [cm/s2]
SI = 71 [cm/s]
JMAISI = 6.0

the spacal and temporal distribution of the slip causedby the main shock estimated from the teleseismic
body-wave by the Japan Meteorological Agency. It

SKM (Sakumagawa)
PGA = 551 [cm/s2]
SI = 90 [cm/s]
JMAISI = 6.1

suggests that three large ruptures, denoted bynumbers 1, 2, and 3 in the figure, occurred; the first

IWK (Iwaki)
PGA = 292 [cm/s2]
SI = 76 [cm/s]
JMAISI = 5.8

two in off Miyagi Prefecture and then the third in off
Ibaraki Prefecture and the second rupture wassignificantly large. As a result, a very large slip over 30
MLIT Seismograph Network

m was likely to have occurred in off Miyagi Prefecture.

IWS (Iwase)
PGA = 903 [cm/s2]
SI = 73 [cm/s]
JMAISI = 6.0

Figure-3. 2. 1. 2 Observations by MLIT Seismograph Network2)

In the following sections, section 3.2.2.1 shows thecharacteristics of the ground motions generated
during the rupture-sequence in the source region andsection 3.2.2.2 presents analytic studies on the design
ground motion for interplate earthquake using strong
motion records. For the analyses of the ground motion
observed at dams and buildings, refer to thesubsections 3.3.4 (4) and 3.3.9.2 (1), respectively.

Surface projection of slip distribution

Moment rate function(a) Osaki Branch-Office
Time after rupture initiation [s]Broken lines and circled numbers correspondto 3 major ruptures.

Down dip

Up dipSlip distribution on the fault plane

Arrows show the movement of hanging wall
seen from foot wall. Green star is the rupture
starting point of the main shock.

Slip
Small
Large
Rupture starting point of the main shock
Epicenters of M>7.0 earthquakes on March 9 or later
Epicenters of M>5.0 aftershocks within one day
Slip distribution of the main shock (5m increment)

1)

Figure-3. 2. 1. 1: Slip Distribution Released by the JMA

57(b) Iwase National Highway Branch-Office
Figure-3.2.1.3: Acceleration Waveforms

100003.2.1.1. Characteristics of the observed groundmotions
1000

Peak response acceleration [cm/s2](1) Ground motion intensity-map and acceleration
waveforms
Figure 3.2.1.2 shows the map of SI values(spectrum intensity: an index for ground motion
intensity, representing the scale of shaking of an
ordinary structure) and the observations at theobservation stations having experienced SI values
over 70 cm/s. (corresponds to 6 upper of theJapanese seismic intensity scale). PGA denotes peak

100
K-NET Tsukidate NS
K-NET Hitachi NS
K-NET Hokota EW
K-NETMotegi EW
K-NET Sendai NS
MLIT KSN EW
K-NET Imaichi EW
MLIT OSK NS

10ground acceleration in the figure. The figure suggests

1
0.1

that strong ground motions were observed in a wide-

1.0

0.5

2.0

10.0

Natural Period [s]range of areas from the northern part of Miyagi(a) Observations in the Tohoku Earthquake

Prefecture to the southern part of Ibaraki Prefecture

10000

because the source region was very large.
Figure 3.2.1.3 shows the acceleration waveforms
observed during the main shock at the Osaki Branch-

1000

Peak response acceleration [cm/s2]

Office (Osaki City, Miyagi Prefecture) and the Iwase
National Highway Branch-Office (Sakuragawa City,
Ibaraki Prefecture) stations. In the waveform observedat the Osaki Branch-Office station, we found two
wave-phases having significantly large amplitude.
Those phases were caused by the two ruptures near
the hypocenter as shown in Figure-3.2.1.1.
On the other hand, we found no such multiplephases in the observations at the Iwase National

100
2011 off Tohoku（K-NET Sendai）
2011 off Tohoku (MLIT OSK)2008 Iwate-Miyagi(KiK-net Ichinoseki-nishi）
2007 off Mid-Niigata（K-NET Kashiwazaki）
2007 Noto（K-NET Anamizu）
2004 Mid-Niigata (JMA Kawaguchi)
2003 off Tokachi (MLIT Taikicho)
1995 Kobe (JR Takatori)

10

1

Highway Branch-Office station; the seismic wave

0.1

caused by the rupture in off Ibaraki Prefecture was

0.5

1.0

2.0

10.0

Natural period [s]dominant over those caused by the first two ruptures(b) Comparison with Past Major Earthquakes

near the hypocenter having attenuated their amplitude

Figure-3.2.1.4: Acceleration Response Spectra

while propagating.

(Damping ratio: 0.05)(2) Acceleration Response Spectrum
Earthquake in Figure-3.2.1.4 (b).

Figure-3.2.1.4 (a) shows the eight acceleration
response spectra (damping ratio: 0.05) of strong

We have obtained numerous records during the

motion records with large instrumental seismic

Tohoku Earthquake with various predominant periods,of the National

short (periods of less than 0.5 s), middle (periods from

Research Institute for Earth Science and Disaster

0.5 to 1 s) and long (periods of longer than 1 s),

Prevention and the MLIT Seismograph Network

corresponding to distance from the source region andduring the Tohoku Earthquake. Two of them aresoil conditions. When we look into the figure focusing

compared with acceleration response spectra ofon the natural periods of 1 to 2 s, which havestrong motion records obtained during recent major

significant effectson structures such as bridges andearthquakes since the 1995 Hyogo-ken Nanbu

low/middle rise buildings, we find that the spectra

intensity obtained by K-NET

3)58

開北橋Bridge
Kaihoku1978
off Miyagi
1978年宮城県沖地震

JRJR鷹取駅
Takatori

1995年兵庫県南部地震
1995 Kobe

大津水位観測所
Ohtsu
W. L. S.

2003年十勝沖地震
2003 off Tokachi

妙見堰Weir
Myoken

2004年新潟県中越地震
2004 Mid Niigata

K-NET柏崎
K-NET
Kashiwazaki

2007
off Mid Niigata
2007年新潟県中越沖地震

K-NET古川
K-NET
Furukawa

2011
off Tohoku
2011年東北地方太平洋沖

K-NET築館
K-NET
Tsukidate2011
off Tohoku
2011年東北地方太平洋沖

K-NET仙台
K-NET
Sendai2011
off Tohoku
2011年東北地方太平洋沖

開北橋Bridge
Kaihoku

2011年東北地方太平洋沖
2011
off Tohoku

K-NET大宮
K-NET
Ohmiya2011年東北地方太平洋沖
2011
off Tohoku

KiK-NET芳賀
K-NET
Haga

2011年東北地方太平洋沖
2011
off Tohoku
0

50

100
150
200
50-galduration(s)
[s]
50gal
継続時間

250

300

Figure-3. 2. 1. 5: Comparison of 50-gal Duration

obtained in the Tohoku Earthquake are smaller thanduration of 178 s, other observation stations in theor the same as those of the devastating 1995 Hyogo-

Tohoku and Kanto regions observed durations longer

ken Nanbu Earthquake (Takatori Station).

than 120 s; generally, the durations observed during

Note that, with regard to the observation by K-NET

the Tohoku Earthquake are longer than those

Tsukidate, which was the only observed record having

observed during the 2003 off Tokachi Earthquake,an intensity 7 according to the JMA announcement,

130s.

variousinvestigations

characteristicofsurfaceincludingsoils

amplificationbyaftershock

3.2.1.2. Research on Design Earthquake Motion forobservations have been conducted. Some of thean Interplate Earthquake

reports have suggested that the observation record,

Since the 1995 Hyogo-ken Nanbu Earthquakewith predominant periods in the spectrum with a(JMA magnitude MJ 7.3), the two-step design

period of 0.2 to 0.3 s, has been influenced by the local

method—using Level 1 earthquake motion and Level 2

geographical conditions and is unlikely to be a typicalearthquake motion—has generally been applied to the4)

observation for the surrounding neighborhood .

seismic design of civil engineering structures. In
designing a highway bridge, for example, two types of(3) Duration of the ground motions

Level 2 earthquake motions are applied; one is for a

One of the outstanding aspects of the groundlarge-scale interplate earthquake (Type I earthquake

motions caused by the Tohoku Earthquake is a long

motion) and the other is for an inland shallow

duration of ground motion resulting from the long-earthquake (Type II earthquake motion).

lasting rupture sequence occurring in the source

The Tohoku Earthquake provided, for the first time,5)

region. Figure-3.2.1.5 shows the comparison of theabundant records of Mw 9.0 class strong motions,

duration observed during the Tohoku Earthquake towhich would help in promoting the analysis of groundthose recorded in the major earthquakes in the past.

motion characteristics in a giant earthquake which had

The duration here is defined as the time between firstbeen underdeveloped so far because of the very low

and last moments that the ground motion amplitude

frequency(synthesized two horizontal components) exceeds 50

earthquakes. Taking account of the prediction that thegals while there are different ways of calculating theTokai, Tonankai, and Nankai Earthquakes, which are

duration.

allofinterplatetheoccurrence

earthquakes

like

of

such

the
6)

giant

TohokuEarthquake,will occur in the near future , we revised

Beside K-NET Furukawa having observed a long59

標準加速度応答スペクトル(gal) 2]
Peakresponse acceleration [cm/s

5000

5000

5000

3000

3000

3000

2000

2000

2000

1000

1000

1000

700

700

700

500

500

500

300

300

300

200

200

H14
TypeタイプⅠ
I (2002)
H24
TypeタイプⅠ
I (2012)タイプⅡType II100
0.1

0.2 0.3 0.5 1
2 3
固有周期
T (s)
Naturalperiod
[s]

100
0.1

5

(a) Type 1 Soil200

H14 タイプⅠType
I (2002)
H24 タイプⅠType
I (2012)
タイプⅡ
Type
II
0.2 0.3 0.5 12 3
固有周期
T (s)[s]Naturalperiod5

H14TypeタイプⅠ
I (2002)
H24
TypeタイプⅠ
I (2012)タイプⅡType II100
0.1

0.2 0.3 0.5 1
2 3
固有周期
T (s)
Naturalperiod[s](b) Type 2 Soil

5(c) Type 3 Soil

Figure-3.2.1.6: Comparison of Standard Acceleration Response Spectra
the Level 2 earthquake motion (Type I) presented inacceleration response spectra for Type I earthquake

the Specifications for Highway Bridges based on the

motionresults of the analyses on the strong motion records

response spectra for Type I and Type II earhtquake

obtained during the Tohoku Earthquake.

motions. The revised spectra for Type I earthquake

and

the

revisedstandard

acceleration

The research conducted for the above-describedmotion have peaks higher than those of the previous

revision of Level 2 earthquake motion (Type I),

spectra for Type I earthquake motion and larger thanpresented in the “Specifications for Highway Bridges

Type II earthquake motion in long period range.

7)

V-Seismic Design” , is introduced in the following as

The previous spectra for Type I earthquake motion

an example of analyses for the characteristics of the

had larger peaks for ground type III (weak groundground motion from the giant interplate earthquake.

among alluvial soil layers) is higher than that forground type I (sound diluvial soil or rock), while the(1) Revising the standard acceleration response

relationship is reversed for the revised spectra. This isspectraa result of the adoption of a trend found in the

The design earthquake motion specified in theSpecificationsforHighway Bridges

is

set

estimated acceleration response spectra that thebyspectrum peak becomes lower in the order of groundmultiplying a correction factor due to damping and atype I, type II, and type III; the trend was foundzone factor to the standard acceleration response

through formulating acceleration response spectra byspectrum specified for each ground type as shown inapplying the ground type factor for each ground typeFigure-3.2.1.6. The standard acceleration spectra forobtained by selectively using the strong ground

Level 2 earthquake motion (Type I) are formulated

motion records with a larger amplitude.

based on, with engineering judgments, the groundmotion inTokyo are during the 1923 Kanto

Earthquake

(Mw

7.9)

extimated

8) and 9)

attenuation relationshipsby(2) Revising the zone factor

enhanced

as Along with revising the standard acceleration

developed using recent

response spectra, weformulated, besides

thestrong motion records and an improved regression

conventional factors, new zone factor to be applied toanalysis method.

Level 2 earthquake motions (Type I) (Figure-3.2.1.7)

Figure-3.2.1.6 illustrates the previous standard

on the basis of the information on the source

60LegendFigure-3. 2. 1. 7: Zone factors for Level 2 Earthquake Motion (Type I), CIz
10) and 11)

having been used for designating thecontrast, we set Mw 9.0 as the upper limit for long

Areas for Intensified/Promoted Earthquake Disasterperiod motions, because the misfit becomes the least

Prevention Measures in 2002 and 2003.The zone

at the Mw of 8.7 to 8.9 as shown in Figure-3.2.1.8 (b)factor of 1.2 was set for the areas predicted to haveas an example of the acceleration response spectrum

stronger ground motions than those experienced inwith natural period of 3 s.

regions

the Tokyo area during the 1923 Kanto Earthquake
taking into account the coupling of earthquakes such(3) Acceleration Waveforms for Dynamic Analysis

as the Off the Pacific Coast of Tohoku Earthquake,

Acceleration waveforms for seismic design throughOff the Pacific Coast of Hokkaido Earthquake, and the

dynamic analyses were produced by a spectral fitting12) and

Tokai-Tonankai -Nankai-Hyuganada Earthquake

technique. Three waveforms were prepared for each13).

ground type using strong motion records from theNote that the attenuation relationship for short2003 off Tokachi and the Tohoku Earthquakes asperiod ground motion were found to have the least

original waveforms.

misfit (square-sum of the residual-errors) with the

Figure-3.2.1.9

observations during the Tohoku Earthquake at Mw of
14)shows,

asan

exampleforcomparison, the original acceleration waveform foras shown in Figure-3.2.1.(a) as an

one of three waveforms for ground type II and theexample of the acceleration response spectrum withrevised waveform; the original waveform (a) and thenatural period of 1 s. Thus, we set the upper limit ofrevised waveform (b) were obtained by spectral fitting

Mw 8.3 for calculating ground motion intensity by thefrom the strong motion records observed respectively

8.1 to 8.3

8)attenuation relationship for short period , and, inon the soil near Itajima-bashi Bridge, Uwajima City,

61

1000

Observed (original)
Observed (corrected)
Mw8.1
Mw9.0

[
] ([cm/s)2]
Peak最大加速度応答
response acceleration

Peak response acceleration [cm/s2]

10000

1000

100

10

100

10
Observed(original)
観測値（補正前）
Observed(corrected)
観測値（補正後）

Mw8.9
Mw9.0
1

10

100
Distance to source fault [km]

1000

10

(a) Peak Response Acceleration (Natural period: 1 s)

100

Distance to source fault [km]1000(b) Peak Response Acceleration (Natural period: 3 s)

Figure-3.2.1.8: Comparison of Estimated Acceleration Response Spectra by Attenuation Relationships to
8)

Observations during the Tohoku Earthquake

Acceleration [cm/s2] Acceleration [cm/s2]

Time [s]Time [s](a) Original Waveform(b) Revised Waveform

Figure-3. 2. 1. 9: Example of Acceleration Waveform of Level 2 Earthquake Motion (Type I) for Dynamic Analysis(one of three waveforms for ground type II)

Ehime Prefecture during the 1968 Hyuganada

Institute for Earth Science and Disaster Prevention,

Earthquake (MJ 7.5), and on the soil in the premisesWest Japan Railway Company, and the Ministry ofof Sendai River and National Highway Office duringLand, Infrastructure, Transportation and Tourism were

the Tohoku Earthquake. It is obvious that one of theused in this study. We would like to express ourremarkable aspects of the ground motions observed

appreciation to these organizations.

during the Tohoku Earthquake is that their duration islong; we decided to apply such a long ground motion

References

waveform to practical analyses because drastic

1) Japan Meteorological Agency. “On the 2011 Off

performance improvements in computers have madethe Pacific Coast of Tohoku Earthquake, the 28th

it practical to conduct dynamic analysis using an input

Report.” 2011.

motion with a long duration.

2) Webpage,

National

Infrastructure
Acknowledgements
Agency,Management.

for

Land

and

“Informationon

Seismograph Network Installed in River/Highway

The observation records obtained by the Japan
Meteorological

Institutethe

National

Facilities.”

Research

http://www.nilim.go.jp/japanese/database/nwdb/in62

dex.htm

tsunami source model for the 1707 Hoei

3) Website, National Resarch Institute for Earthearthquake and simulation of tsunami inundation

Science and Disaster Prevention. “Strong Groundof Ryujin Lake, Kyushu, Japan, J. Geophys. Res.,

Motion Observation Network (K-NET, KiK-net).”116, B02308, 2011

http://www.kyoshin.bosai.go.jp/kyoshin/14) Kataoka, S., and Kaneko, M. “Magnitude of the4) Yamanaka, H., Tsuno, S., Chimoto, K., Yamada,N.,

Fukomoto, S., and2011 Off the Pacific Coast of Tohoku Earthquake

Eto, K.“Estimation ofevaluatedfrom

attenuation

relationships.”site amplification from observation of aftershocks

Proceedings of the 8th Annual Meeting of Japanof the 2011 off the Pacific coast of Tohoku

Association for Earthquake Engineering, 2011:

earthquake and microtremor explorations in the406-407.

vicinity of K-NET Tsukidate station, Miyagi
prefecture, Japan.” Exploration Geophysics Vol.
64, No. 6, 2011: 389-399.
5) Kaneko, M., Kataoka, S.,

Sasaki, T., andTaminoto, S. “Characteristics of the Earthquake
and Ground Motions, Special Issue: Damage to
Coasts and Rivers in the Great East Japan
Earthquake and Status of Recovery.” Kasen, no.
782, 2011: 64-65.
6) The Headquarters for Earthquake Research
Promotion. “Long-term Evaluation of Subductionzone Earthquake.”
http://www.jishin.go.jp/main/p_hyoka02_kaiko.htm
7) Japan Road Association. “Specifications for
Highway Bridges and Commentary Part V:
Seismic Design.” Maruzen, 2012.
8) Kataoka, S., Satoh, T., Matsumoto, S. andKusakabe, T. “Attenuation relationships of groundmotion intensity using short period level as avariable.” Journal of JSCE, Ser. A, Vol. 62, No. 4.
2006: 740-757.
9) Kataoka, S., Matsumoto, S., Kusakabe, T. andToyama, N.

“Attenuation relationships andamplification map for ground motion in rather-longperiod range.” Journal of Japan Society of Civil
Engineering, Ser. A, Vol.64, No.4, 2008: 721-738.
10) Central Disaster Prevention Council: Materials forthe 4th meeting, 2002.
11) Central Disaster Prevention Council: Materials forthe 9th meeting, 2003.
12) Okamura, M., Matsuoka, H.,

Chida, N., andShimazaki, K. “Return Period of the Giant Nankai
Earthquake: Coming in Sight.” Fall Meeting ofSeismological Society of Japan, 2006: 16.
13) Furumura, T., Imai, K. and Maeda, T.: A revised63

3.2.2 Tsunami

The following shows the judgment criteria concerning

3.2.2.1 Coastline

the reliability of the traces.

(1) Tsunami Inundation Survey

A: High reliability. Clear traces, with the smallest margin

1) Definition of Heightof error in measurement.

Figure 3.2.2.1 shows the relationship between

B: Moderate reliability. Traces unclear, so interviews

tsunami height and inundation depth, inundation height

were conducted that made it possible to establish theand run-up height.

water level with some reliability, based on the

Tide Gauge
Tsunami Height
Stationsurrounding situation. Low margin of error in
Inundation
Heightmeasurement.
C: Low reliability. Other factors suggesting waves came

Sea Level
Without Tsunami

up to an extreme degree, or traces where theobservation point is located some distance from theRun-upHeightInundation
Depth

shore and there is a large margin of error in the

Figure 3.2.2.1 Relationship between Tsunami Heightmeasurement.

and Inundation Depth, Inundation Height, and Run-up

D: Minimal reliability. Unclear traces due to overlapping

Height at a Tide Gauge Station (from the Meteorologicalby high tides, typhoons, etc.

Agency website)3) Timing of Survey and Involved Groups2) Survey Method and Survey Items

The most important factor in field surveys concerning

The survey method, survey items and criteria fortsunami is the timing of the visit to the disaster-afflicted

determining the reliability of the traces have been taken

area. If the start of the survey is delayed, the traces offrom the website of the 2011 Tohoku Earthquake

the tsunami disappear and the recollections of

Tsunami Joint Survey Group.

eyewitnesses become vague. However, if it begins too

The measurement of tsunami height (including run-up

early, there is an increased risk that it could hamper

height, inundation height, and rises in the sea level insearch and rescue operations. Moreover, if eachports) in field surveys is usually carried out by means ofresearcher conducts independent field surveys, there is

the following method.

a tendency for them to be concentrated in areas in(i) Finding traces of the tsunami height (e.g. seawater

which there was immense damage and areas in whichmarks, debris, and verbal evidence).

the pattern of damage had particular characteristics.

(ii) Photographing the traces and surrounding area.

Accordingly, in order to obtain survey results effectively,(iii) Using GPS to confirm the position.

while minimizing the burden on the disaster-afflicted(iv)Measuring the height of the traces above theareas, the 2011 Tohoku Earthquake Tsunami Joint

shoreline and their distance from it. (Recording the time

Survey Group was formed and carried out field surveys

at which the shoreline was measured.)

while also coordinating such matters as the areas to be

Table 3.2.2.1 shows an example of the data sheet

surveyed, the timing of this, and the number of staff toused in the field survey.

be involved. Other participants in the 2011 Tohoku
Earthquake Tsunami Joint Survey Group included staff

Table 3.2.2.1 Example of data sheet
1.
SurveyLocations2.
Latitude&Longitude (GPS)

3.
SurveyTime

4.
Measured Value

5.
Reliability6.
HorizontalDistancehours
minutesm units

A-D

m units

7.
8.
Inundatio Topographn Height / y Incline
Run-upHeightDistinction°from universities and research institutes, as well as from9.
Height of
Tide Level
orBenchmark

10.
TsunamiHeightAfter
Correctionm unitsm units

private sector companies and government bodies.
Moreover, a wide range of academic societies wasinvolved, including the Japan Society of Civil Engineers
and the Japan Geoscience Union, so field surveys werecarried out with the cooperation of specialists in a variety
of fields, and the survey data were then consolidated.
These data include the survey results measured by

64

NILIM.

measurements taken by NILIM, distribution of the traceheights along the tsunami run-up direction was4) Survey Results

investigated on the southern Sendai Plain, theThe data concerning inundation height and run-up

Ishinomaki Plain, Rikuzentakata, and the Taro district ofheight consolidated by the 2011 Tohoku Earthquake

Miyako City, in which areas the topography of the

Tsunami Joint Survey Group have been plotted ontsunami run-up zone differed. Then the characteristics ofFigure 3.2.2.2.

the tsunami inundation flow were estimated from these
distribution results. In terms of trends in the run-up, it
was ascertained that the tsunami traces diminishedalong the run-up direction on the plains, where there
was an extensive run-up zone. In contrast, the tsunami
traces did not diminish, but actually rose in some cases
on areas where the run-up zone was confined to anarrower area (Rikuzentakata and the Taro district of
Miyako City). The details are shown below.
(i) Southern Sendai Plain
Figure 3.2.2.3 shows the tsunami trace height surveylines on the southern Sendai Plain. Moreover, Figures
3.2.2.4 - 3.2.2.19 show the trace height distribution for

Figure 3.2.2.2 Coastal Distribution of Traces (Results ofeach of these survey lines. From Figure 3.2.2.4 -Survey by the 2011 Tohoku Earthquake Tsunami Joint

3.2.2.15, we can see that the trace height diminishes

Survey Group [October 4, 2012])

along the tsunami run-up direction. Moreover, in figure

From Figure 3.2.2.2, we can see that the inundation

3.2.2.16 - 3.2.2.19, the trace heights did not diminish

height and the run-up height exceeded 10m on Miyagi

along the tsunami run-up direction. This is thought to be

Prefecture and Fukushima Prefecture. There were

because the plain becomes narrower from the Kasano

many places in this sector that suffered immense

Coast to Isohama Fishing Port and the hilly terrain

damage.

impeded tsunami run-up.

Based on the results above and the trace survey

65

L16
L15
L14

L2 L3
L4

L5 L6
L8
L7

L10

L12

Isohama Fishing Port

Nakahama Coast
Sakamoto River

Kasano Coast

Yoshidahama Beach

Torinoumi Brackish Lake

Right Bank of Abukuma River

Left Bank of Abukuma River

Kabasaki Coast

HirouraRight Bank of Natori River

Left Bank of Natori River

Arahama Coast

Sendai Coast
Left Bank of
Nanakita River

Behind Sendai Port

L1

L13

L11

L9

Figure 3.2.2.3 Tsunami Trace Height Survey Lines (Southern Sendai Plain)(L1: Behind Sendai Shinko Port, L2: Left Bank of the Nanakita River, L3: Sendai Coast, L4: Arahama Coast, L5: LeftBank of the Natori River, L6: Right Bank of the Natori River, L7: Hiroura, L8: Kabasaki Coast, L9: Left Bank of the
Abukuma River, L10: Right Bank of the Abukuma River, L11: Torinoumi Brackish Lake, L12: Yoshidahama Beach,
L13: Kasano Coast, L14: Sakamoto River, L15: Nakahama Coast, L16: Isohama Fishing Port)
6.0

Elevation (ｍ)[ from Tokyo Bay mean sea level]

Tsunami Trace

Ground

5.0

4.0
3.0
2.0

1.0
0.0

0

1000

2000

3000

4000

5000

6000

-1.0

Distance form Sea Wall（ｍ）

Figure 3.2.2.4 Trace Height Distribution (Behind Sendai
Shinko Port)

66

9.0

10.0

8.0

GroundElevation (ｍ)[ from Tokyo Bay mean sea level]

Elevation (ｍ)[ from Tokyo Bay mean sea level]

Tsunami Trace
7.0
6.0

5.0
4.0
3.0
2.0
1.0

Tsunami Trace

9.0

Ground

8.0
7.0
6.0
5.0
4.0

3.0
2.0
1.0

0.0

0.0
0

500

1000
1500
2000
2500
Distance form Sea Wall（ｍ）

3000

3500

0

500

1000
1500
2000
2500
Distance form Sea Wall（ｍ）

3000

3500

Figure 3.2.2.5 Trace Height Distribution (Left Bank of

Figure 3.2.2.8 Trace Height Distribution (Left Bank of

the Nanakita River)

the Natori River)
10.0

Elevation (ｍ)[ from Tokyo Bay mean sea level]

16.0

Elevation (ｍ)[ from Tokyo Bay mean sea level]

Tsunami Trace
14.0

Ground

12.0

10.0
8.0
6.0

4.0

Tsunami Trace

9.0

Ground

8.0
7.0
6.0
5.0
4.0

3.0
2.0
1.0
0.0

2.0

0

500

1000
1500
2000
Distance form Sea Wall（ｍ）

0.0
0

500

1000

1500
2000
2500
3000
Distance form Sea Wall（ｍ）

3500

3000

4000

Figure 3.2.2.9 Trace Height Distribution (Right Bank of

Figure 3.2.2.6 Trace Height Distribution (Sendai Coast)

the Natori River)

12.0

10.0
Tsunami Trace

Ground10.0

Elevation (ｍ)[ from Tokyo Bay mean sea level]

Elevation (ｍ)[ from Tokyo Bay mean sea level]

2500

8.0
6.0
4.0
2.0

Tsunami Trace

9.0

Ground

8.0
7.0
6.0
5.0
4.0

3.0
2.0
1.0

0.0

0.0
0

500

1000
1500
2000
2500
Distance form Sea Wall（ｍ）

3000

3500

0

Figure 3.2.2.7 Trace Height Distribution (Arahama

500

1000

1500
2000
2500
3000
Distance form Sea Wall（ｍ）

3500

4000

Figure 3.2.2.10 Trace Height Distribution (Hiroura)

Coast)

67

12.0

10.0

Ground10.0

Elevation (ｍ)[ from Tokyo Bay mean sea level]

Elevation (ｍ)[ from Tokyo Bay mean sea level]

Tsunami Trace

8.0
6.0
4.0
2.0

Tsunami Trace

9.0

Ground

8.0
7.0
6.0
5.0
4.0

3.0
2.0
1.0

0.0

0.0
0

500

1000

1500
2000
2500
3000
Distance form Sea Wall（ｍ）

3500

4000

0

1000

2000
3000
Distance form Sea Wall（ｍ）

4000

Figure 3.2.2.11 Trace Height Distribution (Kabasaki

Figure 3.2.2.14 Trace Height Distribution (Torinoumi

Coast)

Brackish Lake)

12.0
Tsunami Trace

9.0

Tsunami Trace

GroundElevation (ｍ)[ from Tokyo Bay mean sea level]

Elevation (ｍ)[ from Tokyo Bay mean sea level]

10.0

8.0
7.0
6.0
5.0
4.0

3.0
2.0

Ground

10.0
8.0
6.0
4.0
2.0

1.0
0.0

0.0
0

1000

2000
3000
Distance form Sea Wall（ｍ）

4000

0

500

1000
1500
2000
Distance form Sea Wall（ｍ）

2500

Figure 3.2.2.12 Trace Height Distribution (Left Bank of

Figure 3.2.2.15 Trace Height Distribution

the Abukuma River)(Yoshidahama Beach)

12.0

8.0
Tsunami Trace

Tsunami Trace

Ground10.0

Elevation (ｍ)[ from Tokyo Bay mean sea level]

Elevation (ｍ)[ from Tokyo Bay mean sea level]

3000

8.0
6.0
4.0
2.0
0.0

7.0

Ground

6.0

5.0
4.0
3.0

2.0
1.0
0.0

0

1000

2000
3000
Distance form Sea Wall（ｍ）

4000

0

500

1000
1500
Distance form Sea Wall（ｍ）

2000

2500

Figure 3.2.2.13 Trace Height Distribution (Right Bank of

Figure 3.2.2.16 Trace Height Distribution (Kasano

the Abukuma River)

Coast)

68

14.0

18.0
Tsunami Trace

Ground12.0

Elevation (ｍ)[ from Tokyo Bay mean sea level]

Elevation (ｍ)[ from Tokyo Bay mean sea level]

Tsunami Trace

10.0
8.0

6.0
4.0
2.0
0.0

16.0

Ground

14.0
12.0

10.0
8.0
6.0
4.0
2.0
0.0

0

500

1000
1500
Distance form Sea Wall（ｍ）

2000

2500

0

200

400
600
800
Distance form Sea Wall（ｍ）

1000

1200

Figure 3.2.2.17 Trace Height Distribution (Sakamoto

Figure 3.2.2.19 Trace Height Distribution (IsohamaRiver)

Fishing Port)(ii) Ishinomaki Plain
Figure 3.2.2.20 shows the tsunami trace heightsurvey lines on the Ishinomaki Plain. Moreover, Figures

14.0

Elevation (ｍ)[ from Tokyo Bay mean sea level]

Tsunami Trace

3.2.2.21 and 22 show the trace height distribution for

Ground12.0

each of these survey lines. From Figure 3.2.2.21 and

10.0

Figure 3.2.2.22, we can see that the trace height

8.0

diminishes along the tsunami run-up direction, in the

6.0

same way as on the Sendai Plain.
4.0
2.0
0.0
0

500

1000
1500
Distance form Sea Wall（ｍ）

2000

2500

Figure 3.2.2.18 Trace Height Distribution (Nakahama
Coast)

69

大曲測線
Omagari

浜市測線
HamaichiFigure 3.2.2.20 Tsunami Trace Height Survey Lines (Ishinomaki Plain)
9.0

9.0

Tsunami trace

8.0

GroundElevation (m)[ from Tokyo Bay mean sea level]

Elevation (m)[ from Tokyo Bay mean sea level]

10.0

7.0

6.0
5.0
4.0
3.0
2.0

1.0
0.0

8.0

Tsunami trace

7.0

Ground

6.0
5.0
4.0
3.0
2.0
1.0
0.0

0

500

1000
1500
Distance from sea wall （m）

2000

2500

0

Figure 3.2.2.21 Trace Height Distribution (Hamaichi)

500

1000
1500
2000
2500
Distance from sea wall （m）

3000

3500

Figure 3.2.2.22 Trace Height Distribution (Omagari)(iii) Rikuzentakata
Figure 3.2.2.23 shows the tsunami trace height70

survey lines in Rikuzentakata. Moreover, Figure

tsunami run-up direction, and the trace height continues

3.2.2.24 shows the trace height distribution for each of

to be parallel as same as observed on the southern

these survey lines. In terms of characteristics identified

Sendai Plain. This is thought to be because the plain isfrom the results of survey lines 1-3 in Figure 3.2.2.24,

narrow and the hilly terrain impeded tsunami run-up.

we cannot see any attenuation in trace height along the(Runup trace on the slope. A)(Accretions on wire fabric. A)(Inundation traces in theforests. A)(Inundation traces on the outer wall. A)(Tsunami-induced debris on roads. A)(Tsunami-induced debris on roads. A)(Tsunami-induced debris(Inundation traces at the gym. A)
on roads. A)(Inundation traces at private houses. A)(Inundation traces on the ceiling glass. B)

Survey Line 1(Tsunami-induced debris on power poles. A)(Roof tile removal plus
verbal evidence. A)

Survey Line 2(Tsunami-induced debris on slopes. A)(Tsunami-induced debris on slopes. B)(Breakage of ceiling panels. A)(Inudation trace on the window glass. A)(Inundation trace on the outer wall. A)(Accretions on the handrail. B)(Tsunami-induced debris on slopes. A)(Damage on houses. A)(Driftwood on balconies. A)(Accretions on houses. A)(Tsunami-induced debris
at the roadside station(Michino-eki). A)(Dropout of antenna. A)(Glass breakage in the hotel. A)(Inundation traces in theforests plus tsunami-induced
debris)

L3
Survey Line 3(Break of pine branches. A)

L2

L1(Tsunami-induced debris at the floodgate of the Kawahara River. A)

Run-up height: R
Inundation height: I
Add the reliability (A-D) to the bottom(Mud on the walls of private houses. A)(Tsunami-induced debris on trees. A)

2

Figure 3.2.2.23 Tsunami Trace Height Survey Lines (Rikuzentakata)
Survey L 2
20

18

18

Elevation (m)[ from Tokyo Bay mea sea level]

Elevation (m)[ from Tokyo Bay mea sea level]

Survey L 1
20

16
14
12
10

8

Tsunami Trace

6

Ground

4
2

0

16
14
12
10

8
6

Tsunami Trace

4

Ground

2

0
0

500

1000
1500
Distance from Seawall (m)

2000

2500

0

500

1000
1500
Distance from Seawall (m)

2000

2500

Survey L 3

Elevation (m)[ from Tokyo Bay mea sea level]

20
18
16
14
12
10

8
6

Tsunami Trace

4

Ground

2

0
0

500

1000
1500
Distance from Seawall (m)

2000

2500

Figure 3.2.2.24 Trace Height Distribution (Rikuzentakata)Diagrams plot the results of surveys by the 2011 Tohoku Earthquake Tsunami Joint Survey Group, Tohoku Regional
Development Bureau of MLIT, and NILIM.

71

(iv) Taro District of Miyako City

height in the tsunami run-up direction, and the trace

Figure 3.2.2.25 shows the tsunami trace heightheight continues to be parallel, in the same way as thesurvey lines in the Taro district of Miyako City. Moreover,survey lines on the southern Sendai Plain and in

Figure 3.2.2.26 shows the trace height distribution for

Rikuzentakata, or rises. This is thought to be because

each of these survey lines. In terms of characteristics

the plain is narrow and the hilly terrain impeded tsunami

identified from the results of survey lines 1-2 in Figure

run-up as in Rikuzentakata.

3.2.2.26 , one cannot see any attenuation in trace(Pillar curvature, A)

Run-up height: R
Inundation height: I
Add the reliability (A-D) to the bottom

Survey Line 2

Survey Line 1(Mud on walls, A)(Inundation traces at houses, A)(Tsunami-induced drifting wastes on slopes,
R12.5m (Trace of water level on walls, B)A)(Damages to walls of the hotel, A)
I15.7m (Inundation traces at the hotel, A)
I8.6 m(Inundation traces at storehouses, A)(Windows of the hotel, C)I8.6m (Inundation traces at houses, A)(Tsunami-induced drifting wastes
I7.7m (Inundation trace, A)on slopes, A)(Inundation traces at houses, A)(Tsunami-induced debris on stone steps, B)(Inundation traces at the post office, A)(Damages to houses)(Inundation traces on slopes, A)(Tsunami-induced debris, B)(Tsunami-induced drifting(Inundation traces at the facility
wastes on slopes, A)
for ice making and storage, A)

L2Inundation
affectedby theInundationheights
heightsarewere
affectedbylevee
breach ofratherthan distances
the degree
destructionof coastal
fromcoast.
diketheratherthan distances from thecoast.

L1
Data source• Tohoku Regional
Development Bureau• NILIM• Quick Estimation by the2011 Tohoku Earthquake
Tsunami Joint Survey Group(Inundation traces on slopes, A)

3

Figure 3.2.2.25 Tsunami Trace Height Survey Lines (Taro District of Miyako City)
Survey L 1

Survey L 2
18

Elevation (m)[ from Tokyo Bay mea sea level]

Elevation (m)[ from Tokyo Bay mea sea level]

14
12

10
8
6
Tsunami Trace

4

GroundSea Wall

2

0

16

14
12
10
8
6

Tsunami Trace

4

GroundSea Wall

2

0
0

100

200
300
400
500
Distance from Shoreline (m)

600

700

0

200

400
600
800
Distance from Shoreline (m)

1000

1200

Figure 3.2.2.26 Trace Height Distribution (Taro District of Miyako City)
Diagrams plot the results of surveys by the 2011 Tohoku Earthquake Tsunami Joint Survey Group, Tohoku Regional
Development Bureau of MLIT, and NILIM.

72

calculating tsunami inundation. The grid spacing for the
calculations was set at 1,350m, 450m, 150m, 50m, and
5) Summary

10m from the offshore area including the source area of

Based on the foregoing data, the following facts were

the tsunami, so that it became smaller the closer itsuggested.

came to the area concerned.

(i) On the plains, where there was a broad run-up zone,
the tsunami trace height diminished along theTable 3.2.2.2 Computational Conditions (Southern

direction of tsunami run-up.

Sendai Plain)
Item
Grid
spacing
calculations(ii) In places where the run-up zone was confined to anarrower area, in contrast to the plains, the tsunami
trace height did not diminish along the direction offor

Calculation time
Calculation time interval
Tide level condition

tsunami run-up, but actually rose in some cases (thisappears to be because the hilly terrain impeded
tsunami run-up before it was attenuated by friction

Cutoff depth of wave front
during runup on land
Roughness coefficient
Overflowboundary(breakwater, embankment,etc.)with the land surface and buildings, so the kinetic
energy of the flow was changed into potential energy).
(2) Numerical simulation of Tsunami Inundation
1) Method of Analysis

Content(Wave source - coast)
1,350m, 450m, 150m,
50m, 10m
3 hour
0.1 seconds
High
water
(T.P.
+0.76m)
-5
10 m
0.025
Overflow
calculated
using
the
Honma
formula.

In order to understand the attributes of the tsunami
Moreover, the tide level at the time the tsunami struckthat ran up on shore, the tsunami inundation was(T.P. -0.42m) and tsunami inundation assuming that thecalculated in cases where there was no seawall andseawalls

where there was a seawall, on the southern Sendai

were not destroyed were calculated

separately and, as a result of using inundation data

Plain, in Rikuzentakata, and in the Taro district offrom 177 points to calculate the geometric mean K and

Miyako City, and the inundation depths and flow

the geometric standard deviation κ proposed by Aida

velocities were compared.

3)(1977) , it was ascertained that generally good fitness

1)

Using the Fujii and Satake model ver.4.0 , which is(K=0.87, κ=1.34) could be obtained by setting the slip at

one of the fault plane models for the Great East Japan

1.2 times the level used in the Fujii and Satake model

Earthquake, the movement of the sea bottom wasver.4.0.

2)calculated using a technique following Okada (1992) ,The structural conditions of the seawall and otherand with this as the initial profile, the tsunami inundation

coastal structures were set on the basis of the three

was calculated by means of a two-dimensional shallow

cases shown in Figure 3.2.2.27. In Case 1, it waswater model based on a nonlinear long-wave equation.

assumed that there was no seawall, etc. In Case 2, it

However, of the parameters in the fault model, thewas assumed that the seawall, etc. was the same

slippage was adjusted to increase the fitness of theheight as before the Great East Japan Earthquake,

inundation situation in each sector. Moreover, in thespecifically 3.0-7.2m. In Case 3, it was assumed that

Great East Japan Earthquake, diastrophism caused

the seawall, etc. had a height of T.P. +4.0m, equivalentpronounced ground deformation, so based on the data

to the highest water level reached in the area

measured by the Geospatial Information Authority ofconcerned, which was obtained via calculations ofJapan, land subsidence was set uniformly at 0.5m fromtsunami inundation using the fault model for the 1933

the pre-disaster altitude data in the southern Sendai

Sanriku Earthquake developed by Aida (1977).

Plain, 0.7m in Rikuzentakata, and 0.5m in the Taro

Figure 3.2.2.28 shows changes in the water level

district of Miyako City.

over time at the point where the depth of the water was2) The simulation on the Southern Sendai Plain

10m, in front of the structure (the seaward side of theTable 3.2.2.2 shows the computational conditions for73seawall), and behind the structure (the landward side ofvelocity v at five-second intervals at three set points

the seawall), on a cross-shore transect at Sendai. The

within the inundation zone in Cases 1 and 2. The

maximum water level occurred immediately after the

diagrams

arrival of the first wave and increased in the order Case

inundation depth and flow velocity when the Froude

2, Case 3, and Case 1 at the 10m depth point and in

number is 0.5, 1, and 2. At Point (1) that is the point

front of the structure, with the order being reversed

closest to the sea on the seaward side, the flow velocity

behind the structure. While the water level on the

become high immediately after the tip of the tsunami

seaward side rises due to the seawall, it appears to fallarrives there and the inundation depth increases whileon the landward side.

the flow velocity remains broadly the same; the

also

show

relational

expressionsof

Figure 3.2.2.29 shows the planar distribution of theinundation depth then reaches a maximum when the

maximum inundation depth in each case. With regard

Froude number is less than 1, after which bothto the inundation range, the differences between cases

inundation depth and flow velocity decline. This kind of

are not clear, but the maximum inundation depth

counterclockwise change over time can also be seen at

declined in the order Case 2, Case 3, and Case 1, so a

Point (2), but at Point (1), it is not clear, due to the effecttendency for the maximum inundation depth toof the embankment of the Sendai-Tobu Road. In

decrease as the seawall height increases can be seen.

addition, at all three points, the inundation depth andIn addition, a little to the west of the center of theflow velocity are smaller in Case 2 than in Case 1,

inundation zone, the places where the maximum

demonstrating the effect of a seawall in reducing

inundation depth change substantially meander frominundation depth and flow velocity.

north to south, but this is due to the effects of the

Figure 3.2.2.32 shows the cumulative addition of theembankments built for the Sendai-Tobu Road and thearea of inundation, starting with the area with deeper

Joban Expressway.

inundation levels. Although the size of the total area of

Figure 3.2.2.30 shows the planar distribution of theinundation increases in the order Case 1, Case 3, andmaximum flow velocity in each case. Compared with

Case 2, the difference is comparatively small, while theCase 1, one can see a tendency for the maximum flow

area with an inundation depth of at least 5m in Case 1

velocity to decline in Cases 2 and 3, as the wave

is approximately double that in Case 2. Accordingly, itapproaches the Sendai-Tobu Road and the Joban

would appear that, in this region, a seawall has the

Expressway.

effect of reducing the area in which the inundation

The

diagramsinFigure3.2.2.31

show

the

depth is comparatively high.

relationship between inundation depth h and flow

74

Tagajo City
Case (i) No seawall, etc.

City
Case (ii) Seawall, etc. Tagajo
at current
heightSendai City

Natori City

Sendai City

the Natori River

Natori City

IwanumaCity

Sendai City

the Natori River

Natori City

IwanumaCity

Shibata
Town
the Abukuma River

ShibataTown

Watari Town

KakudaCity

the Abukuma River

KakudaCity
Yamamoto Town

the Abukuma River

Watari Town

KakudaCity

Yamamoto
Town

Marumori
Town

the Natori River

IwanumaCity

ShibataTown

Watari Town

TagajoCity
Case (iii) With a T.P. 4m
seawall

Yamamoto
Town

Marumori
Town

Marumori
Town

Figure 3.2.2.27 Structure Deployment in Each Case (indicated by red line)

Tsunami water levels (cm)

Tsunami water levels (cm)

Tsunami water levels (cm)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)

Case 1Case 2
Case 3Point
withwaterdepth
depth ofPt.1:Pt.1:
Point
with
water
of 10m
10m
Case 1Case 2
Case 3

Seawardsidesideofofthe
the seawall
Pt.2:Pt.2:
Seawardseawall

Tagajo City

Case 1Case 2
Case 3

Sendai City

Pt.2

Pt.3
Landwardsidesideofof thethe seawall
Pt.3:Pt.3:
Landward
seawallNatori City

Elapsed time since the earthquake occurrence (Min)

10m
10m

Pt.1

Figure 3.2.2.28 Time-series Data on Tsunami Water Levels (Using the Geospatial Information Authority of Japan's
Digital Map 25,000 (Map Image) as the background)75

Sendai City

Sendai City

Sendai City

Natori City

Natori City

Natori City

IwanumaCity

IwanumaCity

IwanumaCity

WatariTown

WatariTown

Yamamoto
Town

WatariTown

Inundation
depth (m)Inundation
depth (m)Inundation
depth (m)Under 0.5m
0.5m - 1.0m
1.0m - 2.0m
2.0m - 4.0m
4.0m - 6.0m
6.0m - 8.0m
8.0m - 10.0m
10.0m - 15.0m
Over 15.0m

Under 0.5m
0.5m - 1.0m
1.0m - 2.0m
2.0m - 4.0m
4.0m - 6.0m
6.0m - 8.0m
8.0m - 10.0m
10.0m - 15.0m
Over 15.0m

Under 0.5m
0.5m - 1.0m
1.0m - 2.0m
2.0m - 4.0m
4.0m - 6.0m
6.0m - 8.0m
8.0m - 10.0m
10.0m - 15.0m
Over 15.0m

Yamamoto
Town

Yamamoto
Town

Figure 3.2.2.29 Maximum Inundation Depth (Left: Case 1; Middle: Case 2; Right: Case 3)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)

Sendai City

Sendai City

Sendai City

Natori City

Natori City

Natori City

Iwanuma City

Iwanuma City

Iwanuma City

Shibata Town

Shibata Town

Watari Town

Shibata Town

Watari Town

Kakuda City

Velocity (m/s)

Yamamoto Town

Under 50 cm/s
50 cm/s
100 cm/s
200 cm/s
300 cm/s
400 cm/s
500 cm/s
600 cm/s
700 cm/s
800 cm/s
900 cm/s
1000 cm/s

Watari Town

Velocity (m/s)

Kakuda City

Under 50 cm/s
50 cm/s
100 cm/s
200 cm/s
300 cm/s
400 cm/s
500 cm/s
600 cm/s
700 cm/s
800 cm/s
900 cm/s
1000 cm/s

Yamamoto Town

Kakuda City

Velocity (m/s)

Yamamoto Town

Under 50 cm/s
50 cm/s
100 cm/s
200 cm/s
300 cm/s
400 cm/s
500 cm/s
600 cm/s
700 cm/s
800 cm/s
900 cm/s
1000 cm/s

Figure 3.2.2.30 Maximum Flow Velocity (Left: Case 1; Middle: Case 2; Right: Case 3)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)76

Natori City

Iwanuma City

Watari Town

1010

Fr=0.5③

10Fr=0.5

②

Fr=1

Fr=1
8

6

6

6

h(m)

4

4

Fr=2

Fr=2

2

Fr=2
2

2

0

0

0
0

2

4

6

8

10

0

2

4

v(m/s)

6

8

0

10

Fr=0.5

Fr=0.5

②

Fr=1

6

6

6

2

0
6
v(m/s)

8

10

Fr=2

Fr=2
2

4

Fr=1

4

4

Fr=2

0

10

h(m)

h(m)

h(m)

8

2

8

Fr=0.5

①

8

4

6

10

Fr=1

8

2

4
v(m/s)

100

2v(m/s)

10

③

Fr=1

h(m)

8

h(m)

8

4

Fr=0.5

①

0
0

2

4

6
v(m/s)

8

10

0

2

4

6

8

v(m/s)

Figure 3.2.2.31 Relationship Between Inundation Depth and Flow Velocity (Top: Case 1; Bottom: Case 2)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)

77

10

累加浸水面積(km2)

250
200
150
ケース１
Case 1100

Case 2
ケース２
Case 3ケース３

50
0Inundation
Depth
浸水深

Figure 3.2.2.32 Cumulative Inundation Area by Inundation Depth Zone
3) The simulation on Rikuzentakata

on the basis of the three cases shown in figure 3.2.2.33.

Table 3.2.2.3 shows the computational conditions for

In Case 1, it was assumed that there was no seawall,

calculating tsunami inundation. The grid spacing for theetc. In Case 2, it was assumed that the seawall, etc.

calculations was set at 3,240m, 1,080m, 360m, 120m,

kept the height it was at the time of the Great East

40m, and 10m from the offshore area including theJapan Earthquake, with a height of 4.95-6.15m. In

source area of the tsunami, so that it became smaller

Case 3, it was assumed that the seawall, etc. had athe closer it came to the area concerned.

height of T.P. +5.2m, equivalent to the highest waterlevel reached in the area concerned, which was

Table 3.2.2.3 Computational Conditions

obtained via calculations of tsunami inundation using(Rikuzentakata)the fault model for the 1933 Sanriku Earthquake

Item
Grid
spacing
calculationsfor

Calculation time
Calculation time interval
Tide level condition
Truncation depth of wave
front during runup on land
Roughness coefficient
Overflowboundary(breakwater, embankment,
etc.)

Content(Wave source - coast)
3,240m, 1,080m, 360m,
120m, 40m, 10m
3 hours
0.2 seconds
High
water
(T.P.
+0.65m)-5
10 m

developed by Aida (1977).
Figure 3.2.2.34 shows time-series data for the waterlevel at three points where the water depth was 10m.
After declining from the time of the earthquake until 30
minutes later, the water level sharply rises to T.P. +1315m. Moreover, unlike the southern Sendai Plain,
hardly any difference could be seen between cases interms of the water level at the point where the water

0.025
Overflow
calculated
using
the
Honma
formula.

reached a depth of 10m.
Figure 3.2.2.35 shows the planar distribution of the
maximum inundation depth in each case. The
maximum inundation depth is in excess of 10m over an

Moreover, based on the results of simulations carried

extensive area, but the differences between cases areout by the Iwate Prefecture Expert Committee on

not clear in relation to the inundation range. Moreover,Tsunami and Disaster Prevention Technology, the slip

as in Figure 3.2.2.36, which shows the difference inin the fault model was set at 1.3 times that in the Fujii

maximum inundation depth between Case 1 and Caseand Satake model ver.4.0, in order to increase the2, a tendency can be seen for the maximum inundation

reproducibility of the tsunami in the areas concerned.

depth to be lower on the landward side of the seawall in

The structural conditions of the seawall, etc. were set

case 2, while in Case 1 there is a tendency for it to be78

lower on the seaward side.

seawalls, the flow velocity during the wash andAs shown in Figure 3.2.2.37, the maximum flow

backwash of the first wave becomes enormous, and in

velocity is around 5m/s over an extensive area. When

Case 2, with an seawall, the inundation depth rises

the cases were compared in terms of maximum flow

quickly. At Points (5) and (6), located on the landward

velocity (Figure 3.2.2.38), in the same way as forside of the seawall, the same counterclockwise change

maximum inundation depth, while the velocity wasover time can be seen as on the southern Sendai Plain,higher on the landward side of the seawall in cases with

but the flow velocity is quite a bit lower at the pointa seawall, it was lower on the seaward side of thewhere the inundation depth is at its highest. This

seawall.

indicates that the tsunami that ran up on shore was aThediagramsinFigure3.2.2.39

show

the

standing wave, which is consistent with the fact that therelationship between inundation depth h and flow

trace heights in Rikuzentakata did not diminish in thevelocity v at five-second intervals at three set points

inland direction. It is surmised that the same

within the inundation zone in Cases 1 and 2. At Point

phenomenon occurred in sectors where the plain is(4), sandwiched between the primary and secondary

comparatively narrow, as on the Sanriku Coast.

5.4～8.8m
5.8～6.9m
4.9m
5.1m
5.4～5.7m
5.1m
5.5m

5.5m

6.15m
6.15m

5.5m

4.0m
6.5m

4.95m

※数値は現況高（T.P.+m）Values are heightof seawall

Figure 3.2.2.33 Structure Deployment in Each Case (Left: Case 1; Middle: Case 2; Right: Case 3)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)79

要谷 沖合水深10m地点 津波水位変動

Pt.1

20
検討ケース1Case 1

津波水位（T.P.+m）

15

検討ケース2
Case 2
検討ケース3
Case 3

10
5
0
-5
-10
0

30

60

90

120

150

180

地震発生経過時刻（分）minutes
気仙川 沖合水深10m地点 津波水位変動

Pt.2

20
検討ケース1Case 1

津波水位（T.P.+m）

15

検討ケース2
Case 2

Case 3
検討ケース3

10
5
0
-5
-10
0

30

60

90

120

150

180

地震発生経過時刻（分）minutes
沼田 沖合水深10m地点 津波水位変動

Pt.3

20
検討ケース1Case 1

津波水位（T.P.+m）

15

検討ケース2
Case 2
検討ケース3
Case 3

10
5
0

Pt.2

-5
-10
0

30

60

90

120

150

180

Pt.3

Pt.1

地震発生経過時刻（分）minutesFigure 3.2.2.34 Time-series Data on Tsunami Water Levels (Using the Geospatial Information Authority of Japan's
Digital Map 25,000 (Map Image) as the background)

Maximum
凡 例Inundation
Depth (m)最大浸水深(m)
Under 0.5 m
0.5 m - 1.0 m
1.0 m - 2.0 m
2.0 m - 4.0 m
4.0 m - 6.0 m
6.0 m - 8.0 m
8.0 m - 10.0 m
10.0 m - 15.0 m
Over 15.0 m

Figure 3.2.2.35 Maximum Inundation Depth (Left: Case 1; Middle: Case 2; Right: Case 3)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)80Figure 3.2.2.36 Difference in Maximum Inundation Depth (between Case 1 and Case 2)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)

Maximum Flow Velocity (m/s)
Under 0.5
0.5 – 1.0
1.0 – 1.5
1.5 – 2.0
2.0 – 2.5
2.5 – 3.0
3.0 – 3.5
3.5 – 4.0
4.0 – 4.5
4.5 – 5.0
5.0 – 5.5

5.5 -6.0
6.0 . 6.5
6.5 – 7.0
7.0 – 7.5
7.5 – 8.0
8.0 – 8.5
8.5 – 9.0
9.0 – 9.5
9.5 – 10.0
Over 10.0

Figure 3.2.2.37 Maximum Flow Velocity (Left: Case 1; Middle: Case 2; Right: Case 3)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)81Figure 3.2.2.38 Difference in Maximum Flow Velocity (between Case 1 and Case 2)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)

12

④

Fr=1

10

Fr=0.5

⑤

10

6

0
6

8

10

0
0

2

4

v(m/s)

12

④

6

8

Fr=0.5

Fr=1

10

h(m)

8
6
4

⑤

12

Fr=0.5

10

10

8

8

6

Fr=2

2

0
6
v(m/s)

4

8

10

6

8

10

Fr=0.5

Fr=1

6
4

Fr=2
2

0

4

⑥

Fr=1

Fr=2
2

2

2

v(m/s)

4

0

0

10

v(m/s)

h(m)

12

Fr=2

2

0
4

6
4

2

2

Fr=1

Fr=2

2

0

Fr=0.5

8

4

Fr=2

⑥

10

h(m)

h(m)

6
4

h(m)

Fr=1

8

8

h(m)

12

12

Fr=0.5

0

0

2

4

6
v(m/s)

8

10

0

2

4

6

8

10

v(m/s)

Figure 3.2.2.39 Relationship Between Inundation Depth and Flow Velocity (Top: Case 1; Bottom: Case 2)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)824) The simulation on the Taro District of Miyako Cityis the point at which the water depth is 10m, but at theTable 3.2.2.4 shows the computational conditions forthree points on land (Points (2)-(4)), in Cases 2 and 3,

calculating tsunami inundation. The grid spacing for thewhich assume the existence of a seawall, the time at

calculations was set at 3,240m, 1,080m, 360m, 120m,

which inundation starts is later and the maximum

40m, 20m, and 10m from the offshore area including theinundation depth is lower than in Case 1, whichsource area of the tsunami, so that it became smaller

assumes no seawall.

the closer it came to the area concerned.

According to figure 3.2.2.41, one can see that,compared with Case 1, in which the maximum

Table 3.2.2.4 Computational Conditions (Taro District ofinundation depth reaches at least 10m over an

Miyako City)

extensive area, the maximum inundation depth is lower

Item
Grid
spacing
calculationsfor

Calculation time
Calculation time interval
Tide level condition
Truncation depth of wave
front during runup on land
Roughness coefficient
Overflowboundary(breakwater, embankment,
etc.)

Content(Wave source - coast)
3,240m, 1,080m, 360m,
120m, 40m, 20m, 10m
3 hours
0.2 seconds
High water (T.P. +0.69m)-510 m

in almost all areas within the seawall in Cases 2 and 3,
which assume the existence of a seawall. This tendency
is also clear in figure 3.2.2.42, which compares
maximum inundation depth in Cases 1 and 2, and in thenorthwest of the inundation zone, which is located within
the secondary seawall, there are places where theinundation depth declines by at least 6m.

0.025
Overflow
calculated
using
the
Honma
formula.

Figure 3.2.2.43 shows the planar distribution of the
maximum flow velocity in each case. In Case 1, whichassumes that there is no seawall or similar structure, thearea where the velocity is at least 6m/s is extensive, with

Moreover, based on the results of simulations carriedvelocity reaching at least 8m/s in some parts. In Cases 2

out by the Iwate Prefecture Expert Committee on

and 3, which assume the existence of a seawall, while

Tsunami and Disaster Prevention Technology, the slip

there are places on the immediate landward side of thein the fault model was set at 2.9 times that in the Fujii

seawall where the velocity reaches at least 8m/s, it isand Satake model ver.4.0, in order to increase theless than 6m/s on the seaward side and a little way

fitness of the tsunami in the areas concerned.

further inland from the seawall. The same tendency can

As shown in the upper part of Figure 3.2.2.40, thealso be seen in Figure 3.2.2.44, which compares theconditions relating to structures such as seawalls were

maximum flow velocities in Case 1 and Case 2. The

set as follows: in Case 1, there was assumed to be no

decline in the maximum flow velocity in the cases where

seawall; in Case 2, there was assumed to be a seawall

the existence of a seawall was assumed is pronouncedof the same height as that in place at the time of thecompared with the situation on the southern Sendai

Great East Japan Earthquake (seawall height: T.P.

Plain and in Rikuzentakata; this is believed to be an+10.0m); and in Case 3, the seawall at the front line (theeffect resulting from the fact that the seawall in the Taroyellow line on the map in Figure 3.2.2.40) was assumed

district is comparatively high.

to have a height of T.P. +13.0m (the height at whichThus, it was concluded that a seawall leads to athere would have been no overflow from the 1933

reduction in the maximum inundation depth on its

Sanriku Earthquake).

landward side. However, it is necessary to bear in mind

Looking at time-series data for inundation depth at thethe fact that the maximum flow velocity will increase on

four points shown on the map in Figure 3.2.2.40, there is

the immediate landward side of the seawall.

hardly any difference between cases at Point (1), which

83

②
③

Case (i): No existing structure④

水深 10m 地点①

Case (ii): With existing structure (defense line 10m)
Case (iii): With structure (defense line 13m)

2000

計算ケース①
計算ケース②
計算ケース③

Point (1)1500

津波水位(cm)

500m

0

1000
500
0
-500
-1000
2000 040

Point (2)1500

浸水深(cm)

20

60
時間(分)

80

100

120
計算ケース①
計算ケース②
計算ケース③

1000

500

0

2000

0

20

40

60
時間(分)

80

100
計算ケース①
計算ケース②
計算ケース③

120

20

40

60
時間(分)

80

100
計算ケース①
計算ケース②
計算ケース③

120

20

40

60
時間(分)

80

100

120

Point (3)
浸水深(cm)

1500

1000

500

0

2000 0

Point (4)浸水深(cm)

1500

1000

500

0
0

Figure 3.2.2.40 Time Series Data for Tsunami Water Level(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)84

Figure 3.2.2.41 Maximum Inundation Depth (Left: Case 1; Middle: Case 2; Right: Case 3)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)

Case 2> Case 1

Case 2< Case 1

Figure 3.2.2.42 Difference in Maximum Inundation Depth (between Case 1 and Case 2)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)Figure 3.2.2.43 Maximum Flow Velocity (Left: Case 1; Middle: Case 2; Right: Case 3)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)85

Case 2
> Case 1

Case 2< Case 1

Figure 3.2.2.44 Difference in Maximum Flow Velocity (between Case 1 and Case 2)(Using the Geospatial Information Authority of Japan's Digital Map 25,000 (Map Image) as the background)5) Conclusion

pp.1018-1040, 1992

As a result of tsunami inundation calculations to3) Aida, I.: Simulations of Large Tsunamis Occurring

examine the attributes of the tsunami that ran up on

in the Past off the Coast of the Sanriku District,shore, it emerged that trends in changes over time in

Bulletin of the Earthquake Research Institute,inundation depth and flow velocity differ between the

University of Tokyo, No.52, pp.71-101, 1977

southern Sendai Plain and Rikuzentakata. Moreover, it
was concluded that even if a tsunami higher than thedesign assumptions overtopped the seawall, theseawall itself would have the effect of reducing theinundation depth. As the ability of a seawall to standfirm and achieve its intended purpose, even if it isovertopped by a tsunami, contributes to reducing thedamage in the area behind it, this demonstrates theimportance of giving consideration to building resilient
structures.
References
1) Ministry of Land, Infrastructure, Transport andTourism

National

Institute

for

Land

and

Infrastructure Management: Quick Report of theField Survey and Research on "The 2011 off the
Pacific coast of Tohoku Earthquake" (the Great
East Japan Earthquake), Technical Note of
National Institute for Land and InfrastructureManagement No.636; Technical Note of the
Building Department No.132, pp.4-43-45, 2011
2) Okada, Y.: Internal deformation due to shear andtensile faults in a half-space, Bulletin of the
Seismological Society of America, Vol.82, No.2,

86

3.2.2.2 Ports

coast from Miyako City to Ofunato City, and the coast(1) Tsunami Heightfrom Sendai City to Soma City. At Kamaishi Port in

In order to ensure prompt restoration, it is important

Kamaishi Bay, the trace of the tsunami height was

to investigate the status of damaged facilities and toabout 7-9m while in Ryoishi Bay it was about 16-17m,

find the causes of damage resulting from the Great

immediately north of Kamaishi Bay. This confirmed

East Japan Earthquake. NILIM conducted disasterthe tsunami reduction effect in the bay resulting fromsurveys at the request of MLIT and other bodies. All of

the breakwater at the mouth of the bay. Even within

the surveys were carried out jointly with the Port andneighboring regions, there were variations in the

Airport Research Institute.

tsunami height, due to the effects of existing

These disaster surveys consisted of tsunami

structures and topography.

surveys and earthquake surveys. The following is areport on the results of the tsunami surveys.
Hachinohe(Summary of Surveys)① March 16-19, 2011Kuji

1 staff member dispatched

MiyakoKamaishi
OfunatoKesennuma

to conduct disaster surveys at Kamaishi andOfunato ports② March 16-19, 2011

2 staff members dispatched

to conduct disaster surveys at Hachinohe andIshinomaki
SendaiKuji ports

Soma③ March 27-30, 2011

1 staff member dispatched

to conduct disaster surveys at Kamaishi and

OnahamaMiyako ports④ April 5-8, 2011 2 staff members dispatched to

Hitachinaka

conduct disaster surveys at Soma and Onahama

Tsunami Heightheight(m) height
Inundation

Kashimaports

Run-up height⑤ April 5-6, 2011 1 staff member dispatched to
conduct disaster surveys at Kashima and Ibaraki

Figure 3.2.2.45 Distribution of Traces of Tsunami

ports

Height (Triangles and Circles Indicate Inundation
1)

Heights and Run-up Heights, Respectively)
Figure 3.2.2.45 shows the distribution of traces oftsunami heights obtained from the field surveys (at aIn

Aomori,Iwate,

MiyagiandFukushima

total of 105 points). For details of tsunami heights andPrefectures, damage prediction was carried out for

their measurement conditions, please refer to theeach design tsunami. The following are the predicted

1)

report in the Urgent Survey . It should be noted thattsunami heights for the Meiji-Sanriku Earthquake inall of these tsunami heights are calculated from the1896, which often reached the maximum predictions.

astronomical tide level at the time of the tsunami

In Aomori Prefecture, the maximum inundation heightarrival, because the time when the largest wave of theof 4.0-6.0m was reached in the Shirogane district oftsunami appeared was not clear.

Hachinohe Port. In Iwate Prefecture, the maximum

Focusing on the inundation height (blank triangle inrun-up height of 16.8m was reached in the TaroFig.3.2.2.45), a massive tsunami in excess of 13m

district of Miyako City, while heights were recorded of

was observed along the coast from Kesennuma City

8.4m in the Tsugaruishi district of Miyako, City, 8.0m

to Onagawa Town and the maximum height was

inside Kamaishi Bay in Kamaishi City, and 7.0m insideobserved at Onagawa Port in Onagawa Town (18.4m).

Ofunato Bay in Ofunato City. In Miyagi Prefecture, aA tsunami of almost 10m was observed along the

maximum water level rise of 3.0m was recorded in87Ishinomaki City, and 2.3m inside Sendai Port inindicate the characteristics of the progressive waves.

Sendai City. In Fukushima Prefecture, a maximum

Resonant oscillation subsequently occurred in the

run-up height of 4.9m was reached at Soma Port inchannel.

Soma City, while a height of 4.0m was recorded at
Onahama Port in Onahama City. It should be notedthat the damage prediction survey for Miyagi

Minato Station

Prefecture was released in February 2011, before theoccurrence of Great East Japan Earthquake.

12 km Point

Each tsunami height shown in Figure 3.2.2.45 is

Kainan Tide Station

24 km Point
Legend● Submerged Doppler-type
Directional Wave Meter HF Radar

Komatsushima
Submerged Doppler-type
Directional Wave Meter

much higher than that estimated in the damage
prediction survey for the Meiji-Sanriku Earthquake. In
particular, great tsunami heights were observed along
the coast south of Iwate Prefecture.

GPS Wave Gauge
off Southwest
Wakayama

GPS Wave Gauge
off Tokushima
Kaiyo(2) HF Radar Observation of Tsunami Waves
High-frequency ocean surface radar (HF radar)systems are expected to play an important role intsunami observation, in combination with existing

Figure 3.2.2.46 Monitoring Points of HF Radar

offshore wave gauges. HF radar systems can detect

Systems (Stars) and Sea Surface Monitoring Systems

velocity fluctuations on the sea’s surface in two –(Circles) in Kii Channel, Japan3)

dimensions, as well as the subsequent resonances
due to topographic conditions in bays and channels.
Signals from the tsunami waves induced by the GreatJapan

Earthquake

and

from

Kainan Tide Station

subsequent

Water level (cm)Eastresonances were successfully detected as radial
velocity variability by the HF radar systems installed2),3),4)

by MLIT on the coast of the Kii Channel, Japan
numerical

studies,focusedRadial velocity (cm/s)

andGPS Wave Gauge off Tokushima Kaiyo
GPS Wave Gauge off Southwest Wakayama.

This confirmed the findings of a number of earlier
theoretical

Komatsushima Submerged Doppler-type
Directional Wave Meteron

detecting tsunami waves by HF radar.
The HF radar systems were installed at Saikazaki
and the Minato district of Wakayama City in

4 PM
6 PM
March 11, 2011

8 PM

10 PM

0 AM
2 AM
March 12, 2011

4 AM

12km Point from Minato Station
24km Point from Minato Station
4 PM
6 PM
March 11, 2011

8 PM

10 PM

0 AM
2 AM
March 12, 2011

4 AM

Wakayama Prefecture by MLIT’s Kinki Regional
Development Bureau and are operated continuously.

Figure 3.2.2.47 Detected Sea Surface Heights (Top)

Figure 3.2.2.46 shows the monitoring points of HF

and Radial Velocity (Bottom) from 16:00 on March 11,

radar systems and sea surface monitoring systems

2011 to 04:00 on March 12, 20113)

using offshore wave gauges. From 17:00 on March 11
to 00:00 on March 14, data acquisition was carried out

Indented coastlines are often seen along thefor 10 minutes of every 15 minutes. The surface

Japanese coast. HF radar has the advantage of

velocities were calculated for data recorded between

making it possible to ascertain the spatial distribution

17:00 and 22:38 on March 11.

of surface velocities. In reducing tsunami damage, it is

Figure 3.2.2.47 shows the detected sea surface

important to calculate the spatial distribution of theheights and the radial velocities. A profile of the radial

natural modes for resonant oscillation along the coast

velocities detected by HF radar installed in the Minato

in advance.

district shows that the first to the third tsunami waves

If HF radar could detect tsunami waves and the88subsequent resonances simultaneously and in a

Fields Induced by Tsunami Waves in the Kii

stable manner, it would be useful in making

Channel, Japan, Journal of JSCE, Ser. B2

preparations against tsunami. For this purpose, it is(Coastal Engineering), Vol.68, No.2, 2012 (innecessary (i) to speed up the calculation of the spatial

Japanese)

distribution of surface velocities, (ii) to extend the3) Satoshi

FUJII,

Hirofumi

Masafumi

HINATA,MIYATA,

Keita

observation area and increase its resolution, (iii) to

FURUKAWA,

Takashi

improve communications, and (iv) to improve methods

KOBAYASHI, Masahiro MIZUTANI, Takahiroof data storage and power supply.

KOKAI, Hiroshi NAGAMATSU and Nobuyoshi
KANATSU: Tsunami Observation Using HF

Acknowledgments

Radar in the Kii Channel, Japan, JOS Fall

In conducting disaster surveys, we received the full
supportoftheDevelopment

TohokuBureaus,

and

MLIT,

Kanto

Regional

as

as

well

Meeting in 2011, 2011 (in Japanese)
4) Hirofumi

the

HINATA,FURUKAWA,

SatoshiTomoyaKeita

KATAOKA

Masafumi

KOBAYASHI,

Masahiro

cooperation of the relevant local governments. In HF

MIYATA,

radar observation of tsunami, we made use of data

MIZUTANI, Takahiro KOKAI and Nobuyoshi

from the continuously operated HF radar systems

KANATSU: Propagating Tsunami Wave andinstalled by the Kinki Regional Development Bureau,

Subsequent

MLIT. We would like to take this opportunity to

Detected by HF Radar in The Kii Channel, Japan,

express our deep appreciation for their great

Estuarine, Coastal and Shelf Science 95, pp.268-

assistance.

273, Elsevier, 2011.

References

Useful reference websites

1) Shigeo TAKAHASHI, Kazuhiko TODA, Yoshiaki

Takashi

FUJII,

Resonant

Response

Signals

1) National Institute for Land and Infrastructure

KIKUCHI,

Takahiro

SUGANO,

YoshiakiManagement website: Information related to the

KURIYAMA,

Hiroyuki

YAMAZAKI,

TakashiGreat East Japan Earthquake (in Japanese)

NAGAO, Ken-ichiro SHIMOSAKO, Takashi NEGI,

http://www.ysk.nilim.go.jp/oshirase/uc.html

Jinkatsu SUGENO, Takashi TOMITA, Hiroyasu

http://www.nilim.go.jp/lab/bbg/saigai/h23tohoku/in

KAWAI, Yasuhiro NAKAGAWA, Atsushi NOZU,

dex.html

Osamu OKAMOTO, Kojiro SUZUKI, Yoshiyuki
MORIKAWA,

Taro

ARIKAWA,

2) Aomori Prefectural Government website: Aomori

Mitsuyasu

Prefecture Earthquake and Tsunami Damage

IWANAMI, Taka-aki MIZUTANI, Eiji KOHAMA,

Prediction Survey (in Japanese)

Toru YAMAJI, Kentaro KUMAGAI, Daisuke

http://www.bousai.pref.aomori.jp/kansoku/higaiso

TATSUMI,utei/higaisoutei_top.htm

MakotoIZUMIYAMA,

KatsumiWASHIZAKI,
SEKI,

TakuyaGyeong-Seon3) Iwate Prefectural Government website: Iwate

YEOM, Masahiro TAKENOBU, Hiroaki KASHIMA,

Prefecture Earthquake and Tsunami Simulation

Masayuki BANNO, Yusuke FUKUNAGA, Jyun-

and Damage Prediction Survey (in Japanese)ichiro SAKUNAKA and Yuji WATANABE: Urgent

http://www.pref.iwate.jp/~hp010801/tsunami/yoso

Survey for 2011 Great East Japan Earthquake

kuzu_index.htm

and Tsunami Disaster in Ports and Coasts,

4) Miyagi Prefectural Government website: Miyagi

Technical Note of PARI, No.1231, 200p., 2011 (inPrefecture Fourth Earthquake Damage Prediction

Japanese)

Survey (in Japanese)

2) Hirofumi HINATA, Ryotaro FUJI, Satoshi FUJII,
Yuiti

FUJITA,

Hiroshi

HANADO,

http://www.pref.miyagi.jp/kikitaisaku/jishin_chishiki

Tomoya/H22_disaster_prevention_council_bukai/index.ht

KATAOKA, Masahiro MIZUTANI and Tomoyukim

TAKAHASHI: HF Radar Observation of Velocity

5) Fukushima
89

Prefectural

Government

website:Summary of Fukushima Prefecture Tsunami
Damage Prediction Survey (in Japanese)
http://wwwcms.pref.fukushima.jp/pcp_portal/Portal
Servlet?DISPLAY_ID=DIRECT&NEXT_DISPLAY_ID=U000004&CONTENTS_ID=19543

90

3.2.2.3 Rivers

estuaries on the Sendai Plain, and the results of
1)

At the request of the Ministry's Tohoku Regional

calculations of tsunami runup in this area , the status

Development Bureau, NILIM conducted field surveys

of runup in river channels before the tsunami runupof the Kitakami, Naruse, Natori and Abukuma rivers,

reached the land behind levees along those rivers

aimed at gaining a general understanding of thewas ascertained. Moreover, the configuration of

status of damage, with the objective of obtaining

scouring (formation of pools by erosion during

information that would contribute to disaster recovery

flooding) in flood channels at the edge of the foot ofefforts. This chapter summarizes the water levels andlevee slopes is unclear, even in areas where the waterflow direction based on information gained at the time

overflowed from areas behind the levee, and itof the field surveys, with the addition of various data

appears that there was marked erosion of the slope at

obtained by organization including the Tohoku

the top near the crest of the levee. Accordingly, thisRegional Development Bureau and the Geospatial

would appear to suggest that the water level in the

Information Authority of Japan, such as tsunami runup

river channels rose before it did in the areas behind

traces and image data.

the levees.
Figure 3.3.2.48 shows time-series data for water(1) General Overview of Tsunami Runup in Riverlevels at the time of the tsunami runup, which were

Channelsrecorded at two water level gauging stations on theBased on images of the runup situation at the timeShin-Kitakami River. Between the two gauging

of the first tsunami wave in the vicinity of rivers withstations, the trace water level is lower than the levee

7.0

Water level T.P.(m)Fukuchi 8.57kp【Upper Iino River】：H.W.L.
Earthquake occurrence 14:46

6.0

5.0
4.0

3.0
2.0
1.0

0.0
-1.0

-2.0
14:30

Iino River 14.94kp【Fukuchi】：H.W.L.

15:00

15:30

16:00

16:30

17:00

17:30

18:00

18:30

19:00

Time
19:30

Figure 3.2.2.48 Results of Observation of Changes of Water Level Over Time During the Tsunami Runup on the Kitakami River
7.00
6.50

Name of survey line
3.20

Altitude (m)

6.00

3.25

5.50

3.26
3.27

5.00

3.28

4.50

3.29

4.00

3.30

3.50

3.31
3.32

2011/3/11 16:28

2011/3/11 16:27

2011/3/11 16:26

2011/3/11 16:25

2011/3/11 16:24

2011/3/11 16:23

2011/3/11 16:22

2011/3/11 16:21

2011/3/11 16:20

2011/3/11 16:19

2011/3/11 16:18

2011/3/11 16:17

2011/3/11 16:16

2011/3/11 16:15

2011/3/11 16:14

2011/3/11 16:13

2011/3/11 16:12

2011/3/11 16:11

2011/3/11 16:10

2011/3/11 16:09

2011/3/11 16:08

2011/3/11 16:07

2011/3/11 16:06

3.00

3.33
3.34
3.35

Figure 3.2.2.49 Water Level Changes During the Tsunami Runup Interpreted Via Image Analysis of CCTV Images (Naruse River, 3.4kp)

91

Image at around 15:48 on March 11, 2012 (Viewing the Upstream)

Lower Iino River, at 14.3k of the rightbank of Kitakami River(a) Image extracted from the CCTV image (arrow shows the tsunami wavefront) (b) Result of PIV analysis of a planar projection of theimage on the left
Figure 3.2.2.50 Velocity Distribution on the Water's Surface Calculated Using PIV Analysis of a Planar Projection of a CCTV Image(Kitakami River, 14.3kp)
height (see Figure 3.3.2.51), while at the Fukuchi

floodgate (Kitakami River, 8.6kp), it was not possible

gauging station, located downstream, a rapid rise into calculate the surface velocity because there was a

the water level of approximately 3m in two minutes

lot of vegetation growing between the camera and theoccurred at the time of the tsunami runup during theriver, the camera was located a long way from thefirst wave. This appears to show a fluctuation

river, and the resolution was poor. Using the images

corresponding to the bore-type tsunami runup seenfrom the CCTV camera installed on the downstream

on video footage from a CCTV camera installedside of the Iinogawa Bridge (Kitakami River, 14.3kp),

alongside the river, which captured images of thelocated 5.7km further upstream than the Fukuchi

tsunami runup. Pass points were set for the images

floodgate, it was ascertained that the surface velocity

captured by a CCTV camera on the upstream side ofof the tsunami as it traveled up the right-hand side of

Naruse Bridge (left bank of the Naruse River, 3.4kp),

the river channel was around 5m/s (Figure 3.3.2.50).

and Figure 3.3.2.49 shows the results of having

However, as shown in Figure 3.3.2.50(a), there wasinterpreted fluctuations in the water's surface based

more disturbance on the surface of the water, and theon an analysis of these images. There are several

precision of the calculation was deemed to be low. In

survey lines on the images, from which it is possible to

Figure 3.3.2.48, the wave height dwindles as thesee the same rapid rise in the water level as observed

tsunami travels upstream, but the time when the wateron the Shin-Kitakami River.

level was at its highest was later at Fukuchi gauging

The speed at which the tsunami traveled upstream

station, on the estuary side, than it was at thewas approximately 8m/s, which was calculated as a

Iinogawa

quotient of the time lag between the peak water level

something that should be borne in mind when drawing

during the first wave being recorded at the two

the longitudinal profile of the maximum water level

gauging stations

resulting from tsunami runup.

and the longitudinal distance

upstreamgauging

station,

which

is

between the stations (6.37km). Moreover, the surface
velocity at the time of the tsunami runup was(2) Results of Tsunami Trace Water Level Surveys inmeasured using PIV analysis of the CCTV images

the River Channel and Behind the Levee

when the runup of the first wave occurred; with a

Figure 3.3.2.51 shows the tsunami trace water

maximum velocity of 5m/s, it was even slower thanlevels recorded on the Abukuma, Natori, Naruse, andthe propagation velocity. With regard to the images

Shin-Kitakami rivers. In the trace surveys, there werefrom the CCTV camera installed on the Fukuchi

sectors where the water reached not only the slopes
92

of levees, but also bridges, floodgates, and evenstructures and foothills behind the levees; the traces(3) Effects on Tsunami Runup of Levee Alignment

found in these sectors were limited to structures

and Shape, and Higher Ground, Including Mounds

higher than the aforementioned river levees, so there

and Spurs

are few data. Moreover, it is surmised that even some

Photographs 3.2.2.1 show the direction of flow ofof these structures were submerged, and there are

the tsunami runup in aerial photographs taken of thealso data corresponding to the height (runup height) at

lower reaches of the Shin-Kitakami, Naruse, Natori,

which the tsunami washed up on foothills. Accordingly,

and Abukuma rivers (blue arrows on the photographs),

based on the results of observations during fieldmerged with the runup status categories (see Figure

surveys, Figure 3.3.2.51 shows the results of a rough3.3.2.52). The direction of flow of the tsunami runup

estimate of the distribution of the maximum water

was estimated from such data as the direction inlevel as the curves marked "General trend in the water

which telegraph poles fell, as interpreted from aerial

level change".

photographs, as well as the direction in which

2)

Based on a combination of the distance between

vegetation had fallen and the direction in which thethe water levels behind the levee and on the river sidepaving of levee crests had been detached or washedof it, taking the levee crest as the benchmark, it isaway, as confirmed during field surveys. In addition,

possible to broadly classify the status of tsunami

the arrows on the levees show the direction in which

runup in the river as it travels upstream from thethe water overflowed, either into the river or into theestuary, as shown in Figure 3.3.2.52. The part closest

area behind the levee, but readers should bear into the estuary is the "levee submersion sector", inmind that this is not necessarily the direction of flow inwhich the highest water level reached surpasses thethe strict sense.

crest both behind and in front of the levee, while theBased on these photographs and the trace waterarea upstream is the "levee overflow sector", wherelevels shown in Figure 3.3.2.51, the tsunami runup

the water level behind the levee is lower than thesituation can be summarized as follows.

height of the crest and water from the river in front of
the levee flows over the top of it. Furthermore, even ina) If the levee runs more or less perpendicular to thethe levee submersion sector, there are times - bothstrandline in a broadly straight line

before and after reaching the maximum water level -Typical examples of this are the right bank of thewhen water might overflow from either in front of theNatori River and the left bank of the Naruse River. In

levee or behind it. Upstream of this section is thethe levee submersion sector, traces could be seen on"below-levee runup sector", where the runup on both

both sides of the river levee. Near 1kp on the left banksides of the levee is lower than the height of the leveeof the Naruse River, the paving of the levee crest had

crest.

been washed away on the river side in adjoining

At the observation points at the Watari Bridge, oversections and there appears to be a possibility that

the Abukuma River, the trace water level on the rightflows in a single direction that topped the leveebank side is much higher than that on the left bankoccurredside. With regard these data, the plants caught in the(Photograph 3.2.2.2).

for

a

time

throughout

one

sectionrailings of the Watari Bridge are believed to be traces

Going further upstream from that sector, theresulting from the tsunami runup, and are believed tomaximum water level gradually decreases on bothbe highly reliable as traces indicating the pointsides of the levee, but this occurs to a greater degree

reached by the tsunami. At this location, the riveron the side behind the levee than on the river side, sochannel bends to the left, facing downstream, and it

this sector is the levee overflow sector, where water

appears that the water level was higher because thisflowed over the levee from the river side, and the area

corresponded to the outer bank from the perspective

further upstream again is the below-levee runupof the tsunami runup.

sector.
93

A typical example of this is the area approximatelyb) If there are areas of high ground, such as mounds

1km from the estuary on the right bank of theor spurs, adjacent to the type of river levee referred to

Abukuma River (area downstream of the bend). In thisin a)area, even in the levee submersion sector, slopes

Typical examples of this are the left bank of thecollapsed and pools were formed by erosion during

Natori River and the right bank of the Shin-Kitakami

flooding at the foot of the slopes, due to waterRiver. In the case of the Natori River, this is located at

overflowing from the river side, as will be described in

the road embankment on the Yuriage Bridge, while in

3.3.3(1). Moreover, on the metal handrail above thethe case of the Shin-Kitakami River, such points areparapet on the levee crest, one could see deformation

found where spurs approach the levee (at the 1.2-

surmised to have resulted from the buildup of

1.8km points on the left bank and at the 3.8km point

vegetation and the collision of debris picked up by theon the right bank; in both cases, the spur does nottsunami, which suggested that water overflowed fromcome right up to the levee and there is a waterway

the river side. Furthermore, a section of the parapet

between them) (indicated by means of the graycollapsed and was washed into the area behind thearrows on Photographs 3.2.2.1(a) and (c)).

levee. Based on the situation above, it was surmised

In areas of high ground, it appears that the tsunamithat there were cases in which water from the riverthat traveled up the area behind the levee became

flowed over the levee in sections where the levee isswollen and raised the water level, and flowed overaligned diagonally to the strandline, so that the slope

the levee into the river. Consequently, although theon the river side faces the estuary. Chapter 3.3.3(1)areas downstream of the high ground constitute thebelow examines the status of damage in this section.

levee submersion sector, the disparity with a) caused
the water flowing toward the river in the downstreamd) Sections where the outer bank (from thepart of the high ground to flow over the levee.

perspective of the tsunami runup) of the levee bends

In the case of the Shin-Kitakami River, the area

A typical example of this is the bend on the right

upstream of the spur area was the levee overflow

bank of the Abukuma River. As stated in (2), results

sector in which water flowed over the levee into thesuggestive of an increase in the water level on thearea behind. On the right bank, a levee breach ofouter bank were obtained from the trace survey at theapproximately 400m occurred in this sector. A

Watari Bridge, which is located on the bend in thephotograph has been taken of the situation upstream

river.

of the spur area, where it is surmised that tsunami
inundation occurred after traveling along the waterway(4) Tsunami Wavefront Propagation Interpreted from3)

adjacent to the levee .

Aerial Images

In the case of the Natori River, the water level of the

A Japan Coast Guard helicopter was used to taketsunami runup was much lower upstream of the road.

photographs of the runup situation resulting from the

The tsunami did not top the road embankment nearfirst tsunami wave, focusing on the area from thethe river levee, but traveled upstream around the road

Natori River estuary to the Abukuma River estuary.

embankment, which gradually decreases in height as

Figure 3.3.2.53 shows the places where the position

it runs away from the river levee; it appears that thisof the tsunami wavefront (the boundary between thewas because the wave height decreased due to thearea covered with water due to tsunami runup and theeffects of the increase in the tsunami runup distancearea not covered with water) and its movement could

due to traveling around the road embankment, as well

be confirmed from those images, and the dotted lines

as the effects of current diffusion.

show places where the time spent photographingthem was shorter than in the places indicated by solidc) If the levee runs diagonally to the strandline so thatlines. Photographs 3.2.2.3 show the results ofthe slope on the river side faces the estuary

recording (at intervals ranging from every few seconds
94

to every few dozen seconds) the position of the
wavefront interpreted at each point; at points where it
was possible to spend enough time photographing thearea, the propagation distance L and the time taken to
travel through that sector T were sought, and theaverage propagation velocity was calculated by
dividing L by T. The results were used to confirm thereproducibility of the tsunami simulation carried out by
the Coast Division.
References
1) ResearchCommittee

on

River

TsunamiCountermeasures website:
http://www.mlit.go.jp/river/shinngikai_blog/kasents
unamitaisaku/index.html, 2011
2) Geospatial

Information

Authority

of

Japan

website:http://www.gsi.go.jp/BOUSAI/ h23_tohoku.html
3) Ministry of Land, Infrastructure, Transport andTourism Tohoku Regional Development Bureau
website:http://www.thr.mlit.go.jp/
Bumon/B00097/K00360/taiheiyouokijishinn/kennt
oukai/shiryou2_1.html
Useful reference websites
1) ResearchCommittee

Countermeasures,

on

River

River

TsunamiRunup

TsunamiSimulation Results, Materials Distributed at the
2nd Meeting
http://www.mlit.go.jp/river/shinngikai_blog/kasents
unamitaisaku/index.html
2) Geospatial

Information

AuthorityofJapan,

Information Concerning Disasters
http://www.gsi.go.jp/BOUSAI/ h23_tohoku.html
3) Ministry of Land, Infrastructure, Transport andTourism Tohoku Regional Development Bureau,
Materials from the Research Committee on
Reconstruction Technology for the Levees of theKitakami River, etc.
http://www.thr.mlit.go.jp/
Bumon/B00097/K00360/taiheiyouokijishinn/kennt
oukai/shiryou2_1.html

95

14

Existing levee height (Left bank)

Existing levee height (Right bank)

Foot of slope on the left bank

Foot of slope on the right bankRiver channel along the left bankRiver channel along the right bank

Left bank behind the levee

Right bank behind the levee

Altitude (m)Approximate values based on the traces on
attaching portions of a bridge which were
found by NILM during field surveys

12
Right bankConnection Connection toto hillside hillside

Part of hillside overhung

10

Connection to hillside

Right bank

Right bank

Left bank

Left bankFigure 3.3.2.51(b) Part of8

hillside

Right bank

General trend in thewater level change
inside the river
channelResults of a Traceoverhung
Water Level Survey

6of the Naruse River

Right bank

Right bank
Left bank(data provided by

4

Left bankthe Tohoku
Regional

Levee height

Left bank2

Right bank: General trend
in the water level change
behind the levee

Development
Bureau)

0
(1) 0
(2)

Kitakami Weir

Left bank

Left bank: General trend
in the water level change
behind the levee

Left bank

Right bank

Right bank

1

2

3

4

5

6

Shin-Kitakami Bridge

78

9 10 11 12 13 14 15 16 17

Longitudinal distance (m)Figure 3.2.2.51(a) Results of a Trace Water Level Survey of the Shin-Kitakami River (data provided by the Tohoku Regional Development Bureau)

14

Existing levee height (Left bank)

Existing levee height (Right bank)

Foot of slope on the left bank

Foot of slope on the right bank

Separation levee heightRiver channel along the left bankRiver channel along the right bank

Left bank behind the levee

Right bank behind the levee

Altitude (m)1210Senseki Line

Road embankmenton the old bridge

8
6

Right bank
Right bank

Left bank4

Right bank

Left bank
Levee height2
Left bank

0
(1.0)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

Longitudinal distance (m)Figure 3.2.2.51(b) Results of a Trace Water Level Survey of the Naruse River (data provided by the Tohoku Regional Development Bureau)

96

Existing levee height (Left bank)

Existing levee height (Right bank)

Foot of slope on the left bank

Foot of slope on the right bank

Below the parapet on the right bankRiver channel along the left bankRiver channel along the right bank

Left bank behind the levee

Right bank behind the levee

Trace water level behind the levee on the left bank (T.P.)

Trace water level behind the levee on the right bank (T.P.)

14

Altitude (m)1210
Yuriage Bridge

Natorigawa Bridge

Right bank

8

Left bank

Levee height

Right bank
Left bank6

Right bank4

Left bank: General trend in the water levelchange behind the levee

Right bank: General trend in
the water level change
behind the levee

2
Left bank

0
(1.0)

0.0

1.0

2.0

3.0

4.0

5.0

Longitudinal distance (m)6.0

Figure 3.2.2.51(c) Results of a Trace Water Level Survey of the Natori River (data provided by the Tohoku Regional Development Bureau)

14

Existing levee height (Left bank)

Existing levee height (Right bank)

Foot of slope on the left bank

Foot of slope on the right bank

Right bank without the parapet (Pavement height of levee crests)

River channel along the left bankRiver channel along the right bank

Left bank behind the levee

Right bank behind the levee

Trace water level behind the levee on the left bank (T.P.)

Trace water level behind the levee on the right bank (T.P.)

12
Altitude (m)10Section of theparapet collapsed at
the levee crest on theright bankPartialcollapse

Watari Bridge
Right bank

8

Left bankLeveeheight6
Left bank4
Left bank: General trend in the waterlevel change behind the levee

Right bank

Right bank: General trend in the waterlevel change behind the levee

2

0
(1.0)

0.0

1.0

2.0

3.0

4.0

Longitudinal distance (m)

5.0

6.0

7.0

Figure 3.2.2.51(d) Results of a Trace Water Level Survey of the Abukuma River (data provided by the Tohoku Regional Development Bureau)97Levee submersion
sector

The direction in which
the water overflowed
had variety

Levee overflow sector

Levee
body

Levee
body

Levee
body

Riverside

Below-levee runup sector

Side behind the leveeRiverside

Side behind the leveeSide behind the leveeRiverside

Figure 3.2.2.52 Three Status Categories of Tsunami Runup into Rivers

High ground(Spurs)Levee submersion
sectorSpurs plus
roadembankment

Levee
submersion
sectorUninvestigatedLevee
overflow
sectorHigh ground(Spurs)Below-levee
runup sector
Senseki Line

Shin-Kitakami
BridgeRoad embankmenton the old bridgeLeveeoverflow
sectorPhoto 3.2.2.1(a) Status of Tsunami Runup into the Shin-Kitakami River

Photo 3.2.2.1(b) Status of Tsunami Runup into the Naruse River

Levee submersion
sectorLevee
submersion
sectorLevee overflow
sectorHigh ground(Road
embankment)

Yuriage Bridge

Below-levee
runup sector

Watari Bridge

Levee overflow
sectorBelow-levee
runup sector

Natorigawa Bridge

Photo 3.2.2.1(d) Status of Tsunami Runup into the Abukuma River

Source: Aerial photographs are images taken by the Geospatial
Information Authority of Japan

Photo 3.2.2.1(c) Status of Tsunami Runup into the Natori River

98

Riverside

InlandNatori River

Hiroura 1
Hiroura 2
Hiroura 3
Sendai Airport 1
Sendai Airport 2
Teizan Channel 1
Teizan Channel 2

Natori City

Iwanuma City

Oshiwake Area
Sendai Bay

Photo 3.2.2.2 Detachment of Asphalt Paving at the Crest of the

Watari District

Abukuma River

Levee (near the left bank of the Naruse River, 1kp)
Figure 3.2.2.53 Areas Where the Status of Tsunami Propagation was Checked
Using Images Taken by a Japan Coast Guard Helicopter
Source: Background created using Kashmir 3D http://www.kashmir3d.com/

Natori River

Hiroura 1

L=307m
T=76.2s
V=4.0m/s

Hiroura 2

Hiroura 3

L=130m
T=21.6s
V=6.0m/s

L=23m
T=3.6s
V=6.4m/s

Sendai Airport 1

Sendai Airport 2

L=1,534m
T=474s
V=3.3m/s

L=1,364m
T=386s
V=3.5m/s

Teizan Channel 1

Teizan Channel 2

L=48m
T=11.4s
V=4.2m/s

Oshiwake Area

Abukuma River
Source: Aerial photographs are images
taken by the Geospatial Information
Authority of Japan

Photo 3.2.2.3 Status of Tsunami Propagation at Each Point on Figure 3.3.2.53
99

3.2.3 Soil Liquefaction(1) Committee to Study Countermeasures against Soil
Liquefaction
The Tohoku Earthquake generated soil liquefaction
phenomena over wide areas and caused enormous
damage to houses and residential areas as well as toinfrastructure

facilities.

The

Ministry

of

Land,

Infrastructure, Transport and Tourism organized the“Committee to Study Countermeasures against Soil
Liquefaction” in May 2012, and advanced reviews onthetechnologicalmatters

commontoeachinfrastructure facility such as the grasp of damage
conditions and the verification of the liquefaction
1)

judgment method .
The organization of the committee is shown in Fig.
3.2.3.1;

specifically,

theliquefaction

occurrence

situations in the Kanto area were grasped by fieldsurveys and it was confirmed that the liquefactions
occurred mainly in the reclaimed lands in at least 96
communities.
Based on the comparison and analysis of the actualliquefaction events and the result of the liquefaction
judgment

using

representative

the

FL

liquefaction

method,which

judgment

isa(a) the 2011 Tohoku Earthquake

method,verification was performed on this method and future
problems for its improvement was brought up.
2)

In the following sections (2)-(4), the results

obtained regarding the validity of the FL method andthe applicability of the effective stress analysis aredescribed through the analysis of the strong motion
records from the Tohoku Earthquake performed by
NILIM with cooperation from the Public Works
Research

Institute(Incorporated

administrative

agency). Refer to 3.3.9.2 (6) about the liquefaction
analysis conducted in the architecture field.

Port

Reflect in technical issues
common to these fields

AirportRailroad

Housing &building

River

Road

Sewer

Housing land

Governmentbuilding

Promote study on technical standards and countermeasures in each field

Establish the “Committee to Study Countermeasures against Soil Liquefaction” and discuss investigations
on technical issues common to infrastructures
Results from
Coordination
investigations&
National Institute for Land and Infrastructure Management
cooperation
Geographical Survey InstitutePublic Works Research InstituteJapan Society for Civil Engineers
Building Research InstituteJapanese Geotechnical Society
Port and Airport Research InstituteArchitectural Institute of Japan
Kanto Regional Development Bureau

Figure 3.2.3.1 The organization of the Committee to Study(b) the 1987 off east Chiba earthquake

Countermeasures against Soil Liquefaction

Figure 3.2.3.2 Estimated distribution of peak groundacceleration
100

(2)

Estimationof

distribution

of

peak

groundAgency, K-NET of the National Research Institute foracceleration and validity examination of estimation ofEarth Science and Disaster Prevention (Independent

the FL method

administrative cooperation) and the Ministry of Land,

Since plenty of characteristic ground motions with

Infrastructure, Transport and Tourism were used. Aslong durations have been observed and suchfor the off east Chiba earthquake, public data of thecharacteristics

Architectural Institute of Japan were used.

might

affectthepossibility

3)ofliquefaction, the validity of the FL method was

It was confirmed from the calculation result by theexamined based on the strong motion records and the

FL using this PGA distribution that while the effect ofsurvey of the damage situations.

duration was observed in a part, the liquefaction

The FL method adopts “liquefaction resistant ratio

outbreak was not found at the sites of FL>1.0, andFL” that is the ratio of “dynamic shear strength ratio R”

hence there was no overlooking of the events in theto “shear stress ratio during an earthquake L”, namely,

judgment by the FL method.

2)(FL=R/L) as an index, and judges that the soil layer ofFL less than 1.0 is to liquefy. Since L is calculated(3) Examination of the modification factor based onfrom peak ground acceleration (PGA), distribution ofearthquake motion properties

addition, for a comparison with ground motion with athe dynamic shear strength ratio R is expressed as R

short duration, we estimated distribution of PGA due= cw*RL. Here, RL is the cyclic triaxial stress ratio

to the 1987 off east Chiba earthquake (Japandefined as the ratio (cyclic shear stress/effective

Meteorological Agency magnitude 6.7) in a similar

confining pressure) necessary to produce 5% of axial

manner (Fig.-3.2.3.2). Here, as for the Tohoku

strain at 20 cycles in the cyclic triaxial test. In addition,

Earthquake, public data by the Japan Meteorologicalcw is the modification factor based on earthquake

地震動特性による補正係数
cW properties c
Modification factor
based on earthquake motionw

In the liquefaction judgment using the FL method,

Modification factor based on earthquake motion properties cw

PGA due to the Tohoku Earthquake was estimated. In

Type II earthquake motion

Type I earthquake motion
Northridge Eq. (M6.7)
Kobe Eq. (M7.3)
Off Kushiro (M7.5)
Off SW Hokkaido (M7.8)
Off Tokachi (M7.9)
Off Miyagi (M7.4)
Mid Sea of Japan (M7.7)
Off E Chiba (M6.7)

2.5

TypeタイプⅡの地震動
II earthquake motion

2

1.5

Type
I earthquake motion
タイプⅠの地震動

1

Average(all)
全体平均

0.5

Average(Tohoku)
東北平均
Average(Kanto)
関東平均
Maximum
最大
Minimum
最小

0

0

0.2

0.4

0.6

0.8

繰返し三軸強度比
RL RL
Cyclictriaxial strength ratio

Cyclic triaxial strength ratio RL
4)(a) Specifications for Highway Bridges, V:Seismic Design (b) Strong motion records of the Tohoku Earthquake
Figure 3.2.3.3 Comparison of the modification factor based on earthquake motion characteristics, cw

101

(gal)
500.0

Strongphase 1 Strong
phase 2主要動２
主要動１
Observedmotion at the crown
天端地震計観測波

0.0

Observedmotion at the crown-500.0
天端地震計観測波
Analyticalmotion at the crown
天端解析結果

(gal)
500.0

DB042.001-surf 31.5s-41.5s*-373.5Strongphase 1 0.0
主要動１-500.0

31.5
0.0

33.5
2.0

35.5
4.0

37.5
6.0

39.5
41.5
8.0
10.0
(sec)
DB042_001-surf 79.5s-89.5s

Time
[s]
時間 (s)

(gal)
500.0

Strongphase 2 0.0
主要動２-500.0
0.0
79.5

2.0
81.5

4.0
83.5

6.0
85.5

8.0
87.5

10.0
89.5
(sec)

Time
[s]
時間 (s)

Figure 3.2.3.4 Comparison between the effective stress analysis result and the observation record (acceleration

Excess pore waterpressure [kPa]time history)
100
80
60
40
20
0
-20

Observed
Simulated
0

50

100

150
Time [s]

200

250

300

Figure 3.2.3.5 Comparison between the effective stress analysis result and the observation record (excess porewater pressure)motion properties; cw=1 corresponds to ground motion(4) Reproducible examination by the earthquake

equivalent to 20 cycles and cw greater than or lessresponse analysis of the ground6)

than 1 corresponds to either more than or less than 20

It is necessary to consider the influence of thecycles, respectively.

liquefaction due to rise in excess pore water pressure

We calculated cw from 32 acceleration waveforms
recordedduringtheTohokuEarthquake

for the seismic performance evaluation of levees.

andThere are, however, few examples where theconducted the comparison with and the verification ofacceleration waveform and the excess pore watercw prescribed in Specifications for Highway Bridges

pressure were observed at the same time and at the

4)

Part V: Seismic Design . The factor cw was calculatedsame site during actual earthquakes, and hence there

5)

in a similar manner to Azuma and Tamura (1997)

are few examples for which we compared the excess

based on the damage accumulation theory.

pore water pressure estimated by the earthquake

The analytical results are shown in Fig. 3.2.3.3.

response analysis (effective stress analysis) with theAccording to the comparison with Fig. 3.2.3.3 (a),observed record.

figure (b) shows that the cw values are nearly equal to

Time history records of acceleration at the crown

1 for the range RL < 0.4, i.e. soil with low liquefaction

and base ground and excess pore water pressure at astrength, although they are less than 1 for the rangeliquefiable layer of a levee near Naruse River mouth

RL > 0.4. These values are consistent with thewere obtained during the Tohoku Earthquake. One-

existing results.

dimensional effective stress analysis was conducted

7)

using the acceleration time history record at the base102

ground and the soil survey results at the site obtained

Tourism, news release document: On the study

during installation of the seismographs. The analyticalresults of "Committee to Study Countermeasures

time histories of acceleration at the crown and excess

against Soil Liquefaction," August 31, 2011

pore water pressure at the liquefiable layer were

(Available

compared with the observed records in Figures

http://www.mlit.go.jp/report/press/kanbo08_hh_00

3.2.3.4 and 3.2.3.5.

0154.html)

at

The vibration properties such as the phase of the3) Architectural Institute of Japan: Digitized strong-

acceleration waveforms tended to behave in a similar

motion earthquake records in Japan, Vol. 1: The offmanner to the record, while the short period

eastcomponents were small.

December 17, 1987, 1992

coast

4) Japan

It could be concluded that the excess pore water

of

Road

Chiba

prefecture

Association:

earthquake,

Specifications

forpressure was estimated well as a whole, but the

Highway Bridges and Commentary Part V:

dissipation properties of the water pressure were not

Seismic Design, 2002
5) Azuma T. and Tamura, K.: Evaluation method ofreproduced satisfactorily.

soil resistance against liquefaction considering
cyclic loading effect of earthquake ground(5) Ongoing actions

motions, Civil Engineering Journal, Vol. 39, No. 9,

We are proceeding with examination of dynamic

pp.50-55, 1997

analysis techniques of the ground using the strong
motion records obtained this time in order to improve6) Matsuoka, K., Kataoka, S., Nagaya, K. andthe estimation precision of deformation of the ground,

Kaneko, M.: Earthquake response analyses of aand to contribute to the rationalization of liquefaction

levee using strong motion record during the 2011

measures in turn.

off the Pacific Coast of Tohoku Earthquake,
Journal of Japan Society of Civil Engineers, Ser.
A1

Acknowledgements(StructuralEngineering&

Earthquake

Engineering (SE/EE)), Vol.68, No. 4, pp.I_104-

This study was discussed in the MLIT “Committee

I_110, 2012

to Study Countermeasures against Soil Liquefaction”
and conducted under cooperation with the Soil

7) Yoshida, N. and Towhata, I.: YUSAYUSA-2

Mechanics and Dynamics Research Team, Geology

SIMMDL-2, Theory and Practice(Version 2.10),

and Geotechnical Engineering Research Group,

2005

PublicWorks

Research

Institute(Independentadministrative cooperation).. The observation records
obtained by the Japan Meteorological Agency,
Architectural Institute of Japan, National ResearchInstitute for Earth Science and Disaster Prevention,and the Ministry of Land, Infrastructure, Transport andTourism were used in this study. We would like toexpress our appreciation to these organizations.
References
1) Ministry of Land, Infrastructure, Transport andTourism, news
formationofrelease document: On“Committee

to

the

Study

Countermeasures against Soil Liquefaction,” May
12, 2011.
2) Ministry of Land, Infrastructure, Transport and103

3.3 Technical Support for Restoration/
Reconstruction Measures
3.3.1 Sediment Disasters

12 through April 6).

3.3.1.1 Overview of sediment disasters

unleashed sediment movements (see 3.3.1.3(2)-3).

As a result, about 1,000 locations were extracted as
those where the March 11 earthquake might have

After the Great East Japan Earthquake on March

The extracted slope failure locations were put on an

11, 2011, landslides and slope failures occurred

estimated seismic intensity map published by thewidely in the Tohoku and Kanto regions. A March 12-

Japan Meteorological Agency (Figure 3.3.1.1). While29

multiplewe must note that small-scale slope failures arelandslides and slope failures in Fukushima, Tochigi

difficult to detect, that there are some areas where

and Ibaraki Prefectures.

accumulated snow or clouds made it difficult tohelicopter-based

surveyconfirmed

A total of 141 sediment disasters were reported asconfirm conditions and that sediment movements

caused by the March 11 Great East Japanfailing to become visible cannot be detected, the map

Earthquake,

Naganoindicates that the incidence of slope failures was not

Prefecture earthquake and the March 15 easternso high despite the seismic intensity of upper 5 or

Shizuoka Prefecture earthquake, including 13 debris

more observed in a wide sphere. In contrast, the 2008

flows, 29 landslides, 97 steep slope failures and two

Iwate-Miyagi Inland Earthquake caused about 3,000

snow avalanches. These disasters killed a total of 19

slope failures mainly around the border between thepeople (as of August 6, 2012, by the Ministry of Land,

two prefectures. The sediment disasters stemming

Infrastructure, Transport and Tourism). Particularly atfrom the Great East Japan Earthquake featured asuch locations as Fukushima Prefecture’s Shirakawa

point that the incidence of sediment disasters was not

City and Tochigi Prefecture’s Karasuyama City, thenecessarily proportionate to seismic intensity levels.

the

March

12

northern

Great East Japan Earthquake triggered large-scalelandslides,

wreaking

havoc.

earthquake

withepicenterits

Furthermore,atanFukushima

Prefecture’s Hamadori on April 11 caused slope
failures mainly in Iwaki City. No large-scale landslide
dam was formed through the series of earthquakes.
No major changes were observed at landslide dams
formedthroughthe2008

Iwate-Miyagi

InlandEarthquake and the 2004 Niigata Chuetsu Earthquake.
The National Institute for Land and InfrastructureManagement conducted a March 12-29 helicopterbased survey in the Tohoku region and decipheredsatellite images of the Tohoku and Kanto regions to
widely ascertain sediment disasters caused by theGreat East Japan Earthquake. The satellite image
interpretation covered a total of about 40,000 square
kilometers including areas where seismic intensities of
5 or more on the Japanese scale of 7 were posted
upon the March 11 earthquake. Subject to theanalysis were optical images taken by the PRISM and
AVNIR-2 sensors on the Daichi Advanced Land
Observing Satellite (ALOS) on March 12 and April 10
after the earthquake and post-earthquake highresolution optical satellite images (taken from March104

Table 3.3.1.1. shows relations between recent
Seismic intensityof 7Seismic intensityof upper 6
Seismic intensityof lower 6
Seismic intensityof upper 5
Seismic intensityof lower 5
Seismic intensity
of 4major earthquakes and sediment disasters. Although
the recent earthquakes include only one ocean-trench
earthquake, the table indicates that the incidence ofslope failures is higher for an inland earthquake than

Epicenter

for an ocean-trench earthquake. The indication might

Collapsehave been linked to distances from epicenters,
earthquake

vibration

frequencies,

earthquake

deflections, earthquake durations, etc. Furthermore,
the indication might have complex relations withearthquake

vibration

characteristics,

geologicalcharacteristics as a predisposing cause, slope
directions, geographical characteristics, etc. In the
future, we plan to sort out and analyze factors
contributing to slope failures upon earthquakes.

Figure 3.3.1.1 Estimated Seismic Intensity Map(Japan Meteorological Agency) and Distribution of
Slope Failures Detected through Satellite Images

Table 3.3.1.1. Relations between Recent Major Earthquakes and Sediment Disasters

Major
earthquakes

Date

Earthquake
category

Southern Hyogo(Hanshin Awaji
Great
Earthquake)
Niigata Chuetsu

5:46 January 17,
1995

Inland

17:50 October 23,
2004

Iwate-Miyagi
Inland
Great
East
Japan
Earthquake

Magnitude

Maximum acceleration

7.3

Northsouth
(gal)
818.0

Eastwest
(gal)
617.0

Up
/down
(gal)
332.0

3component
synthesis-

Inland6.8

1716.0

850.0

564.0

8:43 June 14, 2008

Inland7.2

1143.01433.0

14:46
2011

Ocean
trench9.0

2700.01268.0March

11,

Observatory

Maximumseismic
intensity

Kobe
MarineObservatory

7

1750.0NIGO21
Tokamachi

7

3866.04022.0

TWTH25
KansaiUpper 6

1880.02933.0

MYG004
Tsukidate7* Data for the Niigata Chuetsu and later earthquakes are from K-net.
Major
earthquakes

Slope failures detected throughsatellite images & aerial photos
Number Slope
Failuredensityof slope failure
failures location (number/
km2)
surveyPre-failure precipitation
Accumulated
precipitation in a
week
beforefailureEpicenter Horizontal
depth (km) distance toslope
Number of People
People killed
failurekilled or or missing
sediment
location
disasters*1 missing
due
to
(km)
due
to earthquake

Disaster incidence

Accumulated
Amedasprecipitation in a observatory
month
beforefailure105

37 mmKobe

sediment (Total)
disasters
28
40
6,437

375 mm

Koide

225

4

67

10

5-10

293 mmKomanoyu

48

18

23

10

11

77 mm

Komanoyu

114

19

18,131*2

24

area
(km2)
Southern
770
120
6.4
0 mm
Hyogo
(Hanshin
Awaji Great
Earthquake)
Niigata878
20
43.9
132 mmChuetsu
Iwate-Miyagi
3,014
590
5.1
3 mm
InlandGreat East
172
590
0.29
12 mm
Japan
Earthquake*1:Slope failures, landslides, debris flows*2: Fire and Disaster Management Agency, 9/28/2012

16

30

About 150

3.3.1.2 On-site Surveys and Local Responses to

The Miyamachi dangerous steep slope location is at

Sediment Disasters

the center of Mito City. At an upper portion of the

The National Institute for Land and Infrastructure

slope is Mito Kyodo General Hospital. At the lower

Management conducted the following on-site surveys

portion are many houses. The slope is about 15

in response to requests from prefectural governments

meters high. Slope failure prevention facilities haveor regional development bureaus.

been developed since 1971.

[1] On-site survey of damage to steep slope failure

The Great East Japan Earthquake on March 11,

prevention facilities in Miyamachi, Mito City, Ibaraki

2011, caused changes in the slope and facilities,

Prefecture

prompting the Mito municipal government to issue an(ResearchCenterfor

DisasterManagement)

evacuation order for residents (58 people from 30[2] On-site survey of Miyagi Prefecture’s coastal

households) at the lower portion of the slope at 17:50

region (Erosion and Sediment Control Division)

on March 13.

[3] On-site survey of a sediment disaster in Tabito,
Iwaki City, Fukushima Prefecture, caused by anearthquake

with

the

epicenterin2) Disaster situation

Hamadori,

At the hospital site at the upper portion of the slope,

Fukushima Prefecture (Erosion and Sediment Control

cracks were seen for the entire area subject to slope

Division, Public Works Research Institute’s volcano

failure prevention measures. The maximum crack sizeand debris flow team)was 10 centimeters and the maximum crack depth

Results of the on-site surveys have been reported

was about 30 centimeters. Some cracks reachedto survey requestors and published. The results ofbuilding wall borders (under construction) (Photos

these surveys follow:

3.3.1.1, 3.3.1.2, 3.3.1.3, 3.3.1.4 and 3.3.1.5).
Of a facility consisting of a gravity retaining wall and(1) On-site survey of damage to steep slope failurea three-stage block pitching work (Photo 3.3.1.6), theprevention facilities in Miyamachi, Mito City, Ibaraki

top of the slope slipped off forward, distorting thePrefecture

lower block pitching work. No distortion was seen at

The Great East Japan Earthquake on March 11,

the bottom retaining wall (Photo 3.3.1.7).

2011, caused changes in the slope and failure
prevention facilities at a location designated as
dangerous due to possible steep slope failures in Mito
City, Ibaraki Prefecture. The National Institute for Landand Infrastructure Management conducted an on-site
survey there at the request of Ibaraki Prefecture.
1) General situation

106

Photo 3.3.1.1 A crack along a building

Photo 3.3.1.3 A crack is seen in a parking area

Photo 3.3.1.4 The slope’s lower portion as seen fromits top (broken cribwork pieces are scattered)Photo 3.3.1.2 A crack is seen

Photo 3.3.1.5 Broken cribwork pieces that dropped to
the lower portion of the slope107

structural cribwork damage was seen, indicating thatthe cribwork contributed to preventing slope failures.

Photo 3.3.1.8 Earth falls on the right side of thecribwork (Onagawa)
Photo 3.3.1.6 Retaining wall, cribwork, block pitchingwork

Photo 3.3.1.7 Retaining wall, cribwork (no anomaly

Photo 3.3.1.9 Earth falls on the right side of theseen on retaining wall)

cribwork (Ishinomaki)(2) On-site survey of Miyagi Prefecture’s coastal

2) Tsunami’s effects on steep slope failure prevention

regionfacilities

On April 8, 2011, the National Institute for Land and

The retaining wall in Ishinomaki City’s Yoshinocho

Infrastructure Management conducted an on-sitearea (under a soil conservation project) belonged to asurvey of Miyagi Prefecture’s coastal region that was

tsunami-flooded area. But no leg portion erosion was

heavily damaged by the tsunami accompanying thedetected. Nevertheless, there was a 3 centimeter dip

Great East Japan Earthquake.

slip at a construction joint that might have beencaused by the earthquake (Photos 3.3.1.10 and

1) Steep slope failure prevention facilities’ effects on

3.3.1.11).

failures upon earthquake
Earth and rock falls that might have been caused by
the series of earthquakes were confirmed at cribwork
sides in Onagawa Town’s Kawajiri area (Photo3.3.1.8) and Ishinomaki City’s Yoshinocho area (undera soil conservation project) (Photo 3.3.1.9). But no108

Photo 3.3.1.10 A dip slip of the retaining wall
Photo 3.3.1.13 A crack at a cribwork construction joint
The bulging stone guard of a standby retaining wallat the lower portion of the south slope of Mt. Horikiri inOnagawa Town buckled at the upstream slope side
due to the tsunami (Photo 3.3.1.14). Many scratchmarks were seen on the surface of the concrete
retaining wall, indicating that a substantial flow velocity
and debris exerted heavy pressures on the wall in theinitial phase of the tsunami flooding (Photo 3.3.1.15).
Photo 3.3.1.11 A dip slip of the retaining wall(zoomed)Meanwhile, the leg portion soil of the cribwork in
Onagawa Town’s Kawajiri was washed away by thetsunami, leaving the cribwork suspended (Photo3.3.1.13). There was a crack caused by a 3-4
centimeter strike slip at a construction joint (Photo3.3.1.13).
Photo 3.3.1.14 Stone guard buckling

Photo 3.3.1.12 Cribwork leg portion washed away
(Kawajiri area)

Photo 3.3.1.15 Scratch marks on the retaining wall109

erosion and the stability of the entire cribwork may
have to be confirmed and assessed.

In the tsunami-flooded inside of the cribwork,
sprayed materials were broken away or washed away
at many points (Photo 3.3.1.16). But the lath remained3) Situation of the project for conserving a slope foralmost undamaged (Photo 3.3.1.17). We suspected

specific uses at Mt. Horikiri in Onagawa Town

that the cribwork’s functions had not declined so much

The project for conserving a slope for specific uses

(but the lath’s rusting after the seawater flooding wascoordinates steep slope failure prevention and othera matter of concern).

public works programs to secure the stability of the
slope

and

createaregional

infrastructuredevelopment space for the purpose of regional
invigoration. Japan’s first project for conserving asteep slope for specific uses was completed at Mt.
Horikiri in Onagawa Town in FY 1997. On the hilldeveloped through the project are a town hospital, aregional welfare center and a health-care facility forthe elderly. Evacuation steps have been developed forthe hill that has been designated as a site for
evacuation from tsunami or storm waves.
The height of the cut at the project site is given as
Photo 3.3.1.16 Sprayed materials are broken away

16 meters elevation (13 meters in the initial planningfrom the lathstage). But the elevation slightly rises toward thecenter of the hill (Photo 3.3.1.18).

Photo 3.3.1.17 A zoomed lath inside the cribwork
In an area like Onagawa Town where the tsunami
ran over a narrowing inner bay, the leg portion of thecribwork might have been eroded. The degree of such110

Photo 3.3.1.19 The south side wallof the elderly welfare center

Photo 3.3.1.18 An overview of the Mt. Horikiri slope for specific uses
The elderly welfare center (Photo 3.3.1.20) on thesteep slope failure danger zones that could besouth side of the hill is at the lowest site of the hill. On

exposed to tsunamis.

a slope from the center to Kumano Shrine on themountain side was a trace of a flood of nearly 3
meters. A flood of around 1 meter was indicated at the
town hospital on a higher site.
Several cars were suspended at the south wall of
the elderly welfare center (Photo 3.3.1.19). Trash wassuspended on steel bars and the hedge (Photo3.3.1.21) on the east (sea) side of the hill. But thesteel bars and hedge were not damaged so greatly.
There was no trace of debris flowing into the innerhospital and parking area. (This was also confirmed
through a helicopter-based observation on March 12).
Therefore, we suspect that the hill flooding started

Photo 3.3.1.20 A flood trace (at the top of the pole) atat the elderly welfare center on the slightly lower south

the elderly welfare centerside. The flooding speed might have been high in theinitial phase and declined to almost zero when theflood at the elderly welfare center reached 1 to 2
meters. The flood height might have risen gradually.
Left undamaged were two steel stairways (Photo3.3.1.22) built on the sea side for evacuation fromtsunamis.
The abovementioned points confirm that theconservation of slopes for specific uses through suchmeasures as the construction of stairways or
pathways for evacuation and of key facilities on hills
developed with upper slope portions cut are useful at

111

At around 17:16 on April 11, 2011, an earthquakewith a magnitude of 7.0 occurred with the epicenter
traced to Fukushima Prefecture’s Hamadori. The
epicenter depth was estimated to be 5 kilometers. The
maximum seismic intensity of lower 6 was observed in
Fukushima Prefecture’s Iwaki City and Ibaraki
Prefecture’s Hokota City. The earthquake caused
slope failures and landslides mainly in Iwaki. The
National

Institute

for

Land

and

InfrastructureManagement and the Public Works ResearchInstitute’s volcano and debris flow team conducted an
on-site survey of a slope failure in Tabito, Iwaki City,
Photo 3.3.1.21 Steel bars and hedge on the east side

Fukushima Prefecture, on April 13, 2011, at theof the hill

request of the Tohoku Regional Development Bureau.
The survey results are reported as follows:
1) Slope failure data
Figure 3.3.1.2 gives an overview of the slope failure.
Photo 3.3.1.23 indicates the whole picture of the
failure.
Point D

L = About 100m
θ = About 30 degrees

About 50m wide
Point C

About 40m wide

Photo 3.3.1.22 A steel stairway for evacuation fromtsunamis

L = About 60m
θ = About 30 degrees
Point B
L = About 100m
θ = About 20 degrees

About 50m wide
About 2m depth of water← Inflow from the
Point A

About 70m long About 40m wide upper lateral

About 2m wide
About 5m in depth

About 10m wide

→The lower mainstream

About 1min depth
About 1m wide

Figure 3.3.1.2 An overview of the slope failure2) Overview of slope failure
Photo 3.3.1.23 A whole picture of the slope failure

In the failure, a rockslide occurred on a dip slopewith an inclination of about 30 degrees at a ridge(3) A Sediment disaster in Tabito, Iwaki City,(Photo 3.3.1.24). Soil mass collapsed downward overFukushima Prefecture, caused by an earthquake with

about 150 meters from the upper limit of the failure.

the epicenter in Hamadori, Fukushima Prefecture

The point 150 meters down from the upper failure limit112

is a joint between the ridge and a valley on the left
side of the slope (the point is called “the joint”
hereinafter) (Photo 3.3.1.25). The failure/slide might
have occurred as the earthquake shook the entire
ridge where the earthquake vibration was released.
Part of the collapsed soil mass was suspended on aterrace of a milder slope with an inclination of about
15 degrees at the joint. On the surface of the soil
mass are stubs lined up in an orderly manner (Photo3.3.1.26).

Therefore,themovement

patternissuspected as a slide.
Photo 3.3.1.26 Stubs lined up on the terrace
Sediment that flowed down from the terrace wasscattered on the slope and reached a house at thelower portion of the slope (Photo 3.3.1.27). The
sediment mainly included block-shaped rock pieces
measuring 20 to 50 centimeters (Photo 3.3.1.28).
Although the clayish matrix was somewhat wet, thesediment was not as wet as usual debris flow
sediment. The slide might have been a dry sedimentflow (there was no trace of mud water flowing down
Photo 3.3.1.24 An upper portion of the collapse (anfrom the disaster-affected house).

exposed rock is seen at the center)

Sediment includes stubs. Stub roots were relatively
fresh. The situation was different from the so-called
dangerous situation where the shear resistancedeclines as stubs rot in some 10 years after felling.
Root lengths (depths) were as short as 30 to 50
centimeters (Photo 3.3.1.29), indicating that thesurface soil of the slope was thin. Some stubs wereleft untouched at points close to the top of thecollapsed slope (Photo 3.3.1.30), indicating that theslide was not attributable to the water-caused
destabilization of the surface soil at the lower portionof stub roots. The slope failure or slide might have

Photo 3.3.1.25 The left side valley and the joint

been attributable to the earthquake vibration.

113

Photo 3.3.1.27 Sediment reaching a house (seenfrom the terrace at the center of the slope failure)

Photo 3.3.1.29 A stub with shorter roots

Photo 3.3.1.28 Collapsed sediment at the terrace
Based

on

laser

measurement

results,

total

collapsed sediment was estimated at about 25,000
cubic meters (including about 22,000 cubic meters incollapsed sediment left after the failure and about
3,000 cubic meters in sediment blocking up the river
channel). No sediment flowed into the mainstream.
Photo 3.3.1.30 Stubs left close to the top (seen fromthe top)3) Situation of sediment surrounding collapsed area
While there were no cracks or any other indicationsof destabilization on the slope surrounding thecollapsed area, some unstable sediment was seen. At
the right side of the collapsed area’s top was a blockmeasuring 5 meters wide, 10 meters long and 1 meter
thick (Photo 3.3.1.31). Seen on the strip roads at bothsides of the collapsed slope were many cracks normal
to the collapse direction (Photo 3.3.1.32).
On both sides of the collapsed slope were sediment114

upthrusts (1 to 2 meters high) similar to natural banks.
4) Situation of landslide dam

Sediment suspended on the slope has an inclination

Sediment blocked up the river channel including aof some 20 degrees and is relatively porous,

channel consolidation work (measuring about 3

indicating that the sediment is unlikely to flow.

meters deep and 3 meters wide) over an area
measuring 50 meters wide (in the transverse
direction) and 30 meters long (Photo 3.3.1.33).
Sediment volume is estimated at about 3,000 cubic
meters. The flood at the house on the right bank side
was estimated at around 1 meter. The flood volume
was estimated at about 5,600 cubic meters (about 40
m in width (transversal direction) x about 70 m indepth (traverse direction) x about 2 m in depth) (Photo3.3.1.34). The sediment-blocked site was alreadyopened with a cross-section measuring 1 meter deep
and 1 meter wide (at the riverbed) (Photo 3.3.1.35).
Photo 3.3.1.31 A block left on the right side of the top

about 50m
about 30m

Photo 3.3.1.32 A crack seen on a strip road at the left
side of the slope

Photo 3.3.1.33 A blocked river channel seen from thecenter of the collapsed slope

about 40m

about 70m

Photo 3.3.1.34 Situation of a flood pond

115

City, Miyagi Prefecture.
As a result, sediment disasters occurred, including
the Hanokidaira landslide.
In a bid to confirm slope failures, landslides,
landslide dams and other large sediment disasters
caused by the earthquake, the National Institute forLand and Infrastructure Management implemented
the visual interpretation of optical images including
Daichi ALOS PRISM and AVNIR-2 images provided
by the Japan Aerospace Exploration Agency (JAXA).
The survey results are as follows:
Photo 3.3.1.35 A cross section of the blocked river(2) Extracting sediment disaster locations throughvisual interpretation of satellite images1)channel1) Target area and data used for visual interpretation(4) Conclusions of on-site surveys

Table 3.3.1.2 summarizes the data used for the[1] Steep slope failure prevention facilities were notvisual interpretations. Table 3.3.1.3 outlines the ALOS

damaged so much by the earthquake vibration,

optical sensors.

although a stone guard at the upper portion of a

- Decipherment coverage and image situation

retaining wall buckled due to the tsunami. It was

In locations where the seismic intensity of upper 5

confirmed that these facilities demonstrated theiror more is posted, the incidence of slope failures andslope failure prevention functions.

other sediment disasters is likely to be higher.

[2] In areas vulnerable to tsunamis, it is effective to

Therefore, our satellite image interpretation covered

develop evacuation pathways when steep slope

all locations with seismic intensity levels at lower 6 or

failure prevention facilities are constructed.

more and most of the locations with seismic intensity[3] Collapses centered on ridge slopes, graded slopes

levels at upper 5 or more (an area stretching someand100 kilometers from east to west and about 450

fills,

meeting

generally

known

trendsofearthquake-caused slope failures.

kilometers from north to south) in an estimated[4] There was a case where an inland epicentral

seismic intensity map published by the Japanaftershock with less seismic intensity (acceleration)

Meteorological Agency (Figure 3.3.1.3).

than the principal earthquake caused collapses.
[5] Earthquake-caused slope failures can be frequentat mountain ridges and failure scales can beincreased. Therefore, attention must be paid to
disasters at locations that are not viewed as ordinary
sediment disaster danger zones.
3.3.1.3 Survey of Large-scale Collapses Using Optical
Satellite Images(1) Overview of survey
The Great East Japan Earthquake with theepicenter off the Tohoku region unleashed tsunamisthat devastated coastal regions. In inland regions as
well, high seismic intensity levels were observed
widely, including the intensity of 7 posted in Kurihara

116

High-resolution optical satellite images

Figure 3.3.1.3 Locations with Seismic Intensity ofUpper 5 or More, interpretation Coverage and Typesof Satellite Images

Image nameSensorname

GroundTable 3.3.1.2 List of Deciphered Data
ALOS panALOS stereo set (pair)
sharpen images
imagesALOS
AVNIR-2
images・ALOS
AVNIR-2

・ALOS AVNIR-2
・ALOS PRISM
viewing nadir

10 m

2.5 m

・ALOS AVNIR-2
・ALOS PRISM viewing
nadir
・ALOS PRISM viewing
forward (or backward)
2.5 m

High-resolution
optical satellite
images・GeoEye-1,
IKONOS,WorldView-1, etc.

About 1 m or lessresolution
Table 3.3.1.3 Overview of ALOS Optical Sensors
Sensor name

AVNIR-2

PRISM viewing nadir

・PRISM viewing forward
・PRISM viewing backward

Official name

Advanced Visible
and Near Infrared
Radiometer type 2
sensorPanchromatic Remotesensing Instrument for
Stereo Mapping sensor

Panchromatic Remotesensing Instrument for
Stereo Mapping sensor

Ground

10 m

2.5 m

2.5 m

resolution

117

Observation

70 km

70 km

35 km

Color image

Black-and-white images

Black-and-white images

width
Note

The priority order of interpretation images is fromcoloring to prevent landslide dams or natural dams

high-resolution optical satellite images (GeoEye-1,

from being overlooked or to find collapses along rivers

IKONOS and Worldview-1) to ALOS stereo pairaccurately.

images, ALOS pan-sharpen images and ALOS

Rather than ALOS pan-sharpen images alone,

AVNIR-2 images in order by resolution.

ALOS stereo pair images combining pan-sharpen andHigh-resolution optical satellite images were taken

forward-viewed images allowed us to find land rises

for the Tohoku region’s coastal areas and central

and falls at collapsed locations and detect collapses

Sendai after the Great East Japan Earthquake, whilemore accurately.

no such images for inland mountainous areas weretaken after the earthquake (red dot-lines in Figure3) Interpretation results

3.3.1.3).

The interpretation of satellite images was conducted

Among optical satellite sensors, only the ALOS

just after the earthquake and after an increase in post-

AVNIR-2 covered all mountainous locations withearthquake high-resolution optical satellite images.

seismic intensity levels of upper 5 or more subject toIn the interpretation just after the earthquake, about

the interpretation.

200 locations with potential sediment movements

While our interpretation covered a wide area

were extracted, confirming that large collapses

including most of the locations with seismic intensity

forming landslide dams did not occur although therelevels of upper 5 or more, the ALOS AVNIR-2

were the Hanokidaira landslide and other small slope

sensor’s observation width of 70 kilometers and its

failures that had been figured out through helicopter-

nadir-viewed images taken on March 12 and 14

based and other surveys just after the earthquake.

allowed us to figure out an outline of disasters for

The second interpretation improved the accuracy as

most of the coverage at an early stage. As ALOS

an increase in the scope and number of high-images continued to be taken later, we deciphered

resolution optical satellite images allowed us tonadir-viewed images that were expected to feature thecompare clearer and better-resolution images. The

best resolution.

accuracy improvement enabled us to discriminate
collapse-free bare locations (including locations for2) General information about interpretations

felling before the earthquake) and find new collapsed

Less than one-meter resolution images from high-locations. As a result of the second interpretation, we

resolution satellites can be enlarged to indicate

extracted

granulated rocks stemming from slope failures,

sediment movements. Collapsed locations detectedmaking it easier for us to decide whether specificthrough the first and second interpretation arelocations are collapsed or not. More than 2.5-meter

indicated in Figure 3.3.1.4.

resolution images cannot allow us to find granulated
rocks stemming from slope failures. Therefore, lessthan one-meter resolution images are required forfinding small collapses measuring around 50 meters.
Collapsed locations emerging in satellite images
have different colors depending on sunlight. Shadedcollapses can be overlooked. Images of steep valleys
and other shaded locations must be adjusted for

118

about

1,000

locationswithpotentialwas useful for deciding whether any location wascollapsed or not.
[2] About 1,000 collapsed locations extracted throughthe satellite image interpretation represented relatively
large collapses and include large collapsed locations
where no damage was caused. Therefore, theirdistribution differs from the distribution of sedimentdisasters covering small damage-causing collapses in
the number of collapsed locations and positions.
[3] Although a very wide area was subjected to thesatellite image interpretation, the survey allowed us topromptly figure out the space distribution of large
collapses.
The ALOS AVNIR-2 images used mainly for theinterpretation limited extracted collapses to relatively
large ones because of their low ground resolution at
10 meters. We thus failed to detect small collapses.
But we have achieved the purpose of promptly
confirming any collapses large enough to form
landslide dams over a very wide area of high seismic
intensity locations after a giant earthquake like the
Figure 3.3.1.4 Collapsed Location Detection Results

Great East Japan Earthquake.

(3) Satellite Image Survey Conclusions

survey may overlook collapses with flight routes

Over a wide area, particularly, a helicopter-based
We deciphered a wide range of satellite images forlimited, leaving some locations free from observation.

a sediment disaster survey involving the Great East

Therefore, optical satellite images allowing us toJapan Earthquake. According to the survey, thevisually cover the entire area were very useful.

availability and challenges of satellite remote sensing[4] Locations with higher collapse densities were nottechnology for a prompt survey to specify thenecessarily those with higher seismic intensity levels

distribution of sediment disasters are summarized as

posted upon the principal earthquake.

follows:[1] The resolution of 2.5 meters for ALOS pansharpen images allowed us to detect the space
distribution of large collapses measuring more than 50
meters. In order to detect small collapses measuring
less than 50 meters, however, ultra-high-resolution
images with 1 meter or less resolution are required todetect granulated rocks stemming from slope failures
and to discriminate felling and quarry locations fromcollapsed locations.
Large-scale collapses measuring 20 to 30 times
more than the resolution can be extracted more surely.
Smaller collapses are difficult to detect and can beoverlooked.
The stereoscopic vision using stereo pair images

119

3.3.1.4 Assessing Danger of Slope Failures throughearthquake. Finally, we compared and considered theEarthquakes

results of the discriminant’s application to the nine

In order to assess the danger of mountain slope

earthquakes for the verification of its applicability,

failures through earthquakes, the National Institute foranalyzed the applicability and introduced our future

Land and Infrastructure Management built on data forresearch policy.

collapses

throughthe

1995

Southern

Hyogo

Prefecture Earthquake to develop a “discriminant for(1) Applying the discriminant to the Great East Japanassessing the danger of slope failures throughEarthquake

earthquakes”

1) Overview of the discriminant(hereinafterreferred

to

as

“the

2)

discriminant”) . The discriminant is a practical method

The discriminant is an assessment equation derived

that allows us to simply assess the danger offromcollapses even at locations free from earthquake-approach plots an independent variable as shown incaused slope failures by using general available data

Figure 3.3.1.5 to derive a border between a group ofsuch as the inclination, the average curvature factor

variable values for collapse cases and that of values

and the maximum acceleration. But the discriminant

for non-collapse cases and predict possible collapses.

was developed to assess the danger of relatively

A mesh with higher discrimination scores determinedsmall surface slope failures in the Mt. Rokko granite

through the discriminant is interpreted as indicating aarea. The problems with the discriminant are whether

greater vulnerability to collapses. A mesh with lower

it can accurately assess the danger of relatively large

scores may represent a smaller vulnerability tocollapses in areas with complex geological conditions

collapses. The discriminant derived from data ofand whether it is available for an ocean-trenchcollapses in the 1995 Southern Hyogo Prefectureearthquake.

Earthquake is given as follows, using the inclination

We have applied the discriminant to not only theadiscrimination

analysis

approach.

The

and average curvature as predisposed data and theSouthern Hyogo Prefecture Earthquake but also

maximum acceleration as incentive data2):seven others -- the Kozu Island Earthquake, the

F＝0.075I－8.92C＋0.006A－3.228

Niigata Chuetsu Earthquake, the Northern Kagoshima

In the equation, F stands for the discrimination･･･（1）

Miyagiscore, I for the inclination (degrees), C for the average

Peninsulacurvature, and A for the maximum acceleration

Prefecture Chuetsu-oki(cm/s2). The results of the discriminant’s assessment

Earthquake and the Iwate-Miyagi Inland Earthquake --of the Mt. Rokko area are shown in Figure 3.3.1.6.

in a bid to confirm its accuracy. As a result, weBlack triangles in the figure indicate actual collapses.

successfully assessed the danger of collapses for the

Generally, earthquake-caused collapses are moreother seven earthquakes as accurately as for the Mt.

probable as the inclination is greater (but the

Rokko area.

inclination of 60 degrees or more indicates a lower

Prefecture

Earthquake,theNorthern

Prefecture

Earthquake,

the

Noto

Earthquake, the Niigata

collapse probability for reasons such as firmer-rock

In an attempt to verify the discriminant’s applicability
to an ocean-trench earthquake and assess its

slopes),astheaveragecurvatureissmaller

accuracy quantitatively, we applied the discriminant to(indicating a convex slope geographically) and as thethe Kurikoma area where the Great East Japan

maximum acceleration is higher3). Equation (1)Earthquake on March 11, 2011, caused many slope

reflects such trend.

failures. We also compared the results of this2) Methodology

application with those of the discriminant’s application
to the same area regarding the Iwate-Miyagi Inland

Of the data used for calculating the discrimination

Earthquake. Through these procedures, we assessedscore with Equation (1), the inclination and average

the reasonability of the discriminant’s application tocurvature as predisposed data are computed from thethe Great East Japan Earthquake as an ocean-trench

10-meter mesh data of the basic map information

120

図from the Geospatial Information Authority of Japan.
Collapses by the Tohoku
Earthquake
Observation points (Tohoku
Earthquake)

An attenuation model is used to compute themaximum acceleration based on the fault model

LegendEvaluation coverage

Watershed boundary (Except
the Isawa River Basin)
Composite value of three components

published by the National Research Institute for Earth
Science and Disaster Prevention. The attenuation
model is given as follows4):
log10 A＝0.42Mw－log10 (R＋0.025・100.42Mw)－0.0033R＋1.22･･･(2)In the equation, Mw stands for the moment
Iwai Rivermagnitude and R for the distance (in kilometers) froma fault.
Sanhasama Rivera1p+a2q+a0
for the discrimination score
at Point (p・q)

Nihasama River

Linear L

Ichihasama River

Frequency
distribution

for the distanceGroup A

Centroid of Group A

Group A

Point (p・q)
Independent variables X2

Group B

Figure 3.3.1.7 Distribution of Great East Japan
Earthquake Acceleration Data and Collapses in theGroup B

Kurikoma Area

Centroid of Group B

Independent variables X1

Figure 3.3.1.5 Concept of Discrimination Analysis

Legend: Degree of danger by theaverage curvature factor
Danger of relatively small collapses
Danger of somewhat relatively small collapses−
Danger of somewhat relatively large collapses
Danger of relatively large collapses
LegendDiscriminationscore

Ichihasama RiverHigh− Legend −Watershed area

Collapsed location
polygonSlope failures due to the Southern Hyogo
Prefecture Earthquake

Low

Examination coverage

Figure 3.3.1.6 Results from Application of theDiscriminant to the Mt. Rokko Area

Figure 3.3.1.8 Discrimination Assessment Results for
the Kurikoma Area

121

expanded collapses, and estimated these collapses
3) Collapsed location decipherment results
Figure3.3.1.7

combinestheas caused by the Great East Japan Earthquake. For

distributionofreference, the Iwate-Miyagi Inland Earthquake caused

acceleration estimates derived from the attenuationa total of approximately 2,060 collapses in the area.

model with that of collapsed locations detected
through the decipherment of aerial photos for the4) Discriminant application results

Kurikoma area. In the decipherment of aerial photos,

We selected a 10/10 km zone (100 square

we used data from the aerial photos taken by thekilometers) from the Kurikoma area for the application

Geospatial Information Authority of Japan from May toof the discriminant and combined the distribution of

October 2011 after the earthquake and compareddiscrimination scores computed through Equation (1)these data with aerial photos taken in December 2010

and that of actual collapses in Figure 3.3.1.8. Figure

to confirm new and expanded collapses. As a result,3.3.1.8 shows that red zones where collapses were

we detected a total of approximately 330 collapses,indicated by the discriminant as more probableincluding about 300 new collapses and about 20

roughly match actual collapses (red points).

Table 3.3.1.4 Kurikoma Area Decipherment Results and Their Comparison with Results for Other Earthquakes
Southern
Hyogo
Prefecture
Correct
prediction
rate
Missedprediction
failure rate

Northern
Kagoshima
Prefecture

Kozu
IslandNorthern
MiyagiPrefecture

Niigata
Chuetsu

Noto
Peninsula

Niigata
Chuetsuoki

IwateMiyagi
Inland

Great
East
Japan

64.3

49.0

68.9

57.2

74.2

84.4

78.7

69.0

50.2

20.8

48.7

30.0

35.0

11.3

24.1

18.3

25.1

41.3

Prediction

Collapse

Correct prediction rate(A+D)/(A+B+C+D)
B/(A+B)

Collapse

No collapse

Missed prediction rate

A

B

Incorrect prediction
C/(A+C)

Actual

rate

No
C

D
Threat score
Collapse incidence rate (%) – Iwate Earthquake2011 Ocean-trench type: Tohoku
Earthquake
2008 Inland type: Iwate Earthquake

Noto Peninsula Earthquake

Ocean-trench type:
Collapsed
Inland type: Noncollapsed
Ocean-trench type:Non-collapsed

The number of meshes non-collapsed

The number of meshes collapsed

Discrimination score

Inland type: Collapsed

A/(A+B+C)

Niigata Prefecture Chuetsu-oki
Earthquake

Southern Hyogo Prefecture Earthquake

Missed prediction rate

Collapse incidence rate (%) – Tohoku Earthquake

collapse

Northern Miyagi Prefecture Earthquake
Niigata Chuetsu Earthquake

Iwate-Miyagi Inland Earthquake

High

Kozu Island Earthquake

Northern Kagoshima Prefecture
Earthquake

Tohoku Earthquake (This time)
Accuracy

Low

Correct prediction rate

Figure 3.3.1.10 Relative Assessment of Discrimination
Results for the Kurikoma Area
In a bid to quantitatively assess the accuracy, we

Discrimination scorecomputed the correct prediction and missed prediction
Figure 3.3.1.9 Collapse Incidence Rate by Score

rate. The correct prediction rate represents the rate ofRange

meshes where collapse and non-collapse cases were122

predicted correctly. The missed prediction rate is thewere set for 240 municipalities in 17 prefectures inrate of meshes where collapses actually occurred

April 2011 just after the Great East Japan Earthquake.

despite non-collapse case predictions (Table 3.3.1.4).

As for sediment disasters that occurred between

A mesh where a collapse occurred is defined as a

March 11 and October 31, 2011, after the Great East

mesh located at the head of the collapsed location

Japan Earthquake, precipitation data have been

polygon data, as is the case with the assessment

collected for verifying the effectiveness of the tentative

method for other earthquakes.

standards (Figure 3.3.1.11). We would like to try to

As a result, as shown by Figure 3.3.1.9, we can see

improve the accuracy of approaches for assessing thethe trend that the collapse incidence rate for each

danger of slope failures through earthquakes, whilescore range increases as the discrimination scorecollecting new data.

rises. But this trend is unclear when compared to thediscrimination results for the Iwate-Miyagi InlandThe

correct

prediction

ratecomputed at 50.2% with the missed prediction rate at
41.3%, indicating a roughly lower accuracy ascomparedtoaccuracies

indicatedfor

CL (normal)
CL (tentative)
Snake CurvewasHourly rainfall (mm/h)

Earthquake.

otherearthquakes as shown in Figure 3.3.1.10. The low

Accident occurrence

rate of collapse incidences caused by the Great East
Japan Earthquake in the area might be related to thisSoil water index (mm)discrimination result.

Figure 3.3.1.11 Image of Disaster Detection under
Tentative Standards for Sediment Disaster Warnings(2) Conclusion
In this study, the discriminant based on slope

Acknowledgement

failures in the Mt. Rokko area caused by the Southern
Hyogo Prefecture Earthquake was applied to the

In compiling this section, we used the estimatedKurikoma area where many failures were caused byseismic intensity map by the Japan Meteorologicalthe Great East Japan Earthquake as an ocean-trench

Agency. For the survey of collapses using satellite

earthquake. The application results indicated lower

images, we received ALOS optical images from theaccuracy than ones for earlier inland earthquakes,

Japan Aerospace Exploration Agency (JAXA) underbeing possibly influenced by the low rate of collapse

our joint study with JAXA. We here make a mostincidences. The discriminant's applicability to thecordial acknowledgement to these agencies.

slope failure danger assessment for ocean-trench
References

earthquakes should await further study.
At present, the National Institute for Land and1) Mizuno, M., Sato, T., Hayashi, S., Nishi, M.,

Infrastructure Management is studying an approach to

Katsura, S. and Nakagawa, K.: Investigation ofquantitatively assess post-earthquake loosening ofLandslides

Causedbyslopes from the viewpoint of post-earthquake slope

Earthquake

Using

Opticalfailure danger assessment. For sediment disaster

International

warnings

Engineering Vol. 4, No. 2 , pp.48-56, 2011

operatedbytheMinistry

of

Land,

Journal

the
of

2011

TohokuSatellite

Images,ErosionControl

Infrastructure, Transport and Tourism and the Japan2) Uchida, T., Kataoka, S., Iwao, T., Matsuo, O.,

Meteorological Agency, 50-80% of the normal

Terada, H., Nakano, Y., Sugiura, N., Osanai, N.:standard is tentatively used for locations posting

A Study on Methodology for Assessing theseismic intensity levels at upper 5 or more, withPotential of Slope Failures during Earthquakes,

consideration given to slopes’ loosening caused by

National Institute for Land and Infrastructureearthquake vibrations. In fact, tentative standards

Management paper No. 204, pp.91, 2004

1233) Nakamura, H., Tsuchiya, S., Inouye, K., Ishikawa,
Y.: Earthquakes and Sediment Control, pp.190,
20004) Fukushima, Y., Tanaka, T.: Revised Attenuation
Relation of Peak Horizontal Acceleration by Usinga New Data Base, Collection of Speech Papers
for the Seismological Society of Japan, p.116,
1992

124

3.3.2 Sewage

In order to specify factors behind sewage treatment
plant and pipe damage caused by the Great East

(1) Damage Survey and Local Responses
sewageJapan Earthquake, the National Institute for Land andtreatment plants and relevant facilities on the coast of

Infrastructure Management conducted a questionnaire

the Tohoku and Kanto regions. A total of 120 sewage

survey of disaster-hit local governments (of which

treatment plants and 112 pumping stations received

69% gave valid responses). Figure 3.3.2.1 indicatesdamage including function injuries and breakdowns. A

factor-by-factor breakdowns of damage to individual

total of 642 kilometers sewer pipe conduits in 132

sewage treatment plant facilities (one plant wasmunicipalities were damaged due mainly to ground

divided into 23 facilities) and to sewer pipe conduits.

Thetsunamidevastatingly

damagedserviceAt sewage treatment plants, the tsunami accounted

disruptions including service suspensions lasting forfor 54% of the damage, followed by earthquake

some one month.

motion for 41% and ground liquefaction for 4%. Of

liquefaction,bringing

about

sewageAs the Great East Japan Earthquake brought aboutdamage to sewer pipe conduits, ground liquefaction

greater damage than assumed for in the rules foraccounted for about 90%. Of the percentage,

mutual support among local governments, the Ministryliquefaction of backfill soil for sewer pipe conduits,of Land, Infrastructure, Transport and Tourism

which has been a problem since the Niigata Chuetsu

undertook coordination regarding sewage services.

Earthquake, was responsible for 66 percentage points,

The ministry gave top priority to measures against

becoming the largest factor behind the pipe damage.

untreated sewage releases and urban overflow

Surrounding ground liquefaction accounted for 25

streams and established a sewage disaster recovery

percentage points, far larger in the past.

headquarters at the Tohoku Regional Development

Sewage treatment plants in coastal cities are built

Bureau for liaison and coordination with relevant

relatively close to the sea due to the adoption of theorganizations. The National Institute for Land andgravity flow system and the necessity of releases toInfrastructure Management sent a tec-force the day

public waters. Because of their proximity to the sea,

after

recoverythe tsunami injured constructed structures with its

headquarters. A total of 18 officials from the institutestrong wave power and flooded electrical andwere sent for technical guidance and other operations

mechanical equipment. But existing anti-earthquake

over one month.

guidelines

theearthquaketolaunchtheforsewagefacilities

includednodescriptions about anti-tsunami measures. Therefore,a panel to be discussed later has considered asewage facility design concept giving considerations
to anti-tsunami measures, based on the damage
realities. While many sewer pipe facilities lacking antiearthquake measures were damaged, surrounding
ground liquefaction led sediment to flow into lateralsewer pipe conduits to clog up them or affect flows,
though with main sewer pipes damaged little. Given
these findings, anti-earthquake guidelines have been
expandedtorequiretraditionalanti-liquefaction

measures for backfill soil liquefaction zones and for
Photo 3.3.2.1 Sewage Disaster Recovery

lateral sewer pipes that had been exempted from

Headquarters (Tohoku Regional Development

such measures and were damaged by surrounding

Bureau)ground liquefaction.

(2) Overview of damage

125

Factors behind sewage facility damage
Earthquake

1%
41%
54%

Factor-by-factor breakdowns ofdamage (Treatment plant facilities)

4%

Groundliquefaction

88
35%

106
42%

TsunamiWave pressure bytsunamiDebris by tsunami
Flooding by tsunami

Others59
23%

Factors behind sewer pipe conduit damage

4% 5%

0%

Earthquake motion

25%

Factor-by-factor breakdowns ofdamage (Pumping station
facilities)

Liquefaction of backfill
soil

66%

Surrounding groundliquefaction
Tsunami (There remain
unsurveyed points)

72
33%

86
39%

OthersWave pressure bytsunamiDebris by tsunami
Flooding by tsunami

Figure 3.3.2.1 Factors behind Sewage Facility
Damage6328%(3) Tsunami damage to sewage treatment plants andpumping stations
Tsunami damage factors include wave pressure,

Figure 3.3.2.2 Factor-by-factor Breakdowns of

castaways and flooding. Figure 3.3.2.2 indicates

Damage to Sewage Treatment Plants and Pumping

factor-by-factor breakdowns of damage to sewage

Stations

treatment plants and pumping stations (divided into 23
facilities). Each of flooding, wave pressure andcastaways accounts for a large share of damage. At
sewagetreatment

plants,particularly,

flooding

accounted for a larger share at 42%, followed by 35%
for wave pressure. Mechanical energy might havebeen coupled with wetting and submerging to inflatedamage. Representative damage is shown in Photo3.3.2.2(a) Wave pressure-caused damage to a sea-side wall126

suspended. Some large plants took more than one
year for recovering normal functions or ending service
suspensions. Given that the Higashinada sewage
treatment plant in Kobe took about100 days to restore
normal functions after the Southern Hyogo Prefecture
Earthquake, service suspension periods for theseplants after the Great East Japan Earthquake wereComplete damage (Including partial
damage)longer.

(b) Castaways’ direct damage to a building

Seismic damage

31.4% 15.7%

Complete damage (Including partial
damage)Photo 3.3.2.2 Representative Tsunami-caused

14.8%
Civil engineering
Construction
Mechanical

Tsunami damage 19.9% 20.2%0%(c) Flooding-caused damage to interior equipment

38.1%

Seismic damage

47.1%

29.6%

Electrical

30.3%

50%

100%

5.9% 38.2%

8.8%
Civil engineering
Construction
Mechanical

Tsunami damage

40.5% 0.0% 39.2%

20.3%

Electrical

Damage to Sewage Treatment Plants and Pumping0%

Stations

20%

40%

60%

80% 100%

Figure 3.3.2.3 Relative Comparison of Earthquakeand Tsunami-caused Damage

We here would like to analyze the characteristics oftsunami-caused damage to sewage treatment plant120

facilities (23 facilities) and pumping station facilities
The number of sewage treatment(five facilities) based on information from thequestionnaire survey. In a comparison of earthquake
motion-and tsunami-caused

damage,tsunami-caused damage tended to focus on electricalequipment both at sewage treatment plants andpumpingequipment

stations(Figurebreakdowns

3.3.2.3).

stemming

Electrical
from

100
80

Service suspension

60

emergency responding

40

Partial suspension

20
0

the

submersion or washout of control panels in switchdayrooms or water treatment facilities accounted for mostFigure 3.3.2.4 Service Suspensions at Sewageof the damage to electric equipment. Figures 3.3.2.4-5

Treatment Plants

indicates that tsunami-damaged sewage treatment
plants took more time for their restoration than otherdamaged plants that recovered normal functions
roughly in one month, for which services were

127

100
80

Depth of tsunami-caused floods

The number of sewage treatment

120

Without
tsunamiWith tsunami

60
40
20
0

day

88%

8.5m～9.0m
8.0m～8.5m
7.5m～8.0m
7.0m～7.5m
6.5m～7.0m
6.0m～6.5m
5.5m～6.0m
5.0m～5.5m
4.5m～5.0m
4.0m～4.5m
3.5m～4.0m
3.0m～3.5m
2.5m～3.0m
2.0m～2.5m
1.5m～2.0m
1.0m～1.5m
0.5m～1.0m
0m～0.5m

12%100%

Total service suspension

100%
100%
100%

Partial suspension

50%

No functional problems

50%
100%
67%

25%

8%

80%

100%

100%

Figure 3.3.2.5 Comparison of Tsunami-caused and

0%

20%

40%

60%

Damage rate

Other Damage to Sewage Treatment Plants

Figure 3.3.2.6 Relationship between Depths of
The relationship between the depths of tsunami-

Tsunami-caused Floods and Degrees of Service

caused floods and damage to equipment within

Suspensions (sewage treatment plants)

sewage treatment plants (Figures 3.3.2.6-7) showsthat plant service suspensions were limited to partial
Depth of tsunami-caused floods

suspensions for cases where the depths were lower.
More than a half of the sewage treatment plants were
subjected to total service suspensions for cases
where the flood depths exceeded 1 to 1.5 meter. This
trend could be useful for considering the scope of antitsunami measures and specific approaches. Facilities
where there were no functional problems even withhigh flood depths of 8.5 to 9 meters are civil

100%

8.5m～9.0m
8.0m～8.5m
7.5m～8.0m
7.0m～7.5m
6.5m～7.0m
6.0m～6.5m
5.5m～6.0m
5.0m～5.5m
4.5m～5.0m
4.0m～4.5m
3.5m～4.0m
3.0m～3.5m
2.5m～3.0m
2.0m～2.5m
1.5m～2.0m
1.0m～1.5m
0.5m～1.0m
0m～0.5m

75%
80%
100%
100%
100%
29%

57%

equipment

discharge/outlet

atconduits.

inlet
The

and
rate

75%
40%

40%

Total service suspension

22%

Partial suspension

25%
20%

No functional problems

100%
75%

25%

80%
0%

20%

20%

40%

60%

80%

100%

Damage rate

effluent
of

14%

100%
44%
100%

33%

engineering facilities that have no electrical ormechanical

25%
20%

Figure 3.3.2.7 Relationship between Depths of

total

Tsunami-caused Floods and Degrees of Service

suspensions was higher for pumping stations evenSuspensions (pumping stations)with lower flood depths. The relationship between thedepths of tsunami-caused floods and the types ofdamaged facilities (Figures 3.3.2.8-9) shows that
Depth of tsunami-caused floods

facilities damaged by floods of up to 4 meters weremainly mechanical and electrical facilities. Higher
depths led to complex damage (affecting civilengineering, construction, mechanical and electricalfacilities). Anti-tsunami measures may thus berequired for mechanical and electrical facilities forcases where flood depths are up to 4 meters. For
cases where flood depths are higher than 4 meters,

8.5m～9.0m
8.0m～8.5m
7.5m～8.0m
7.0m～7.5m
6.5m～7.0m
6.0m～6.5m
5.5m～6.0m
5.0m～5.5m
4.5m～5.0m
4.0m～4.5m
3.5m～4.0m
3.0m～3.5m
2.5m～3.0m
2.0m～2.5m
1.5m～2.0m
1.0m～1.5m
0.5m～1.0m
0m～0.5m

15%
30%

12%
21%

39%
27%

21%

25%

25%
33%
25%
43%

Civil engineering0%

anti-tsunami measures may be required for all types

33%

25%
13%
20%
25%
29%

25%

29%
21%
30%

21%

20%

33%
50%
29%

17%

29%
29%

60%

MechanicalElectrical

21%
33%

70%
40%

Construction

0%
80%

100%

Damage rateof facilities. At pumping stations, meanwhile, thedamage rate was high for mechanical and electricalFigure 3.3.2.8 Relationship between Depths offacilities irrespective of the flood depths.

Tsunami-caused Floods and Degrees of Damage byType of Facilities (sewage treatment plants)

128

Depth of tsunami-caused floods

8.5m～9.0m
8.0m～8.5m
7.5m～8.0m
7.0m～7.5m
6.5m～7.0m
6.0m～6.5m
5.5m～6.0m
5.0m～5.5m
4.5m～5.0m
4.0m～4.5m
3.5m～4.0m
3.0m～3.5m
2.5m～3.0m
2.0m～2.5m
1.5m～2.0m
1.0m～1.5m
0.5m～1.0m
0m～0.5m

50%
50%
38%
50%
25%
22%
21%
17%
27%
21%
9% 9%
13%

earthquake-caused liquefaction of backfill soil by

50%

25%
22%
14%
27%

compacting backfill soil around sewer pipe conduits at

50%
38%
50%

25%

25%
33%
43%
27%

40%
100%
17%
29%
45%
50%
38%

a degree of 90% or more. In regions affected by theGreat East Japan Earthquake, no cases have been

25%
22%
21%
30%
33%

confirmed for the implementation of this anti-

Civil engineering

33%
36%
50%
50%

Constructionliquefaction measure. But road consruction guidelines

Mechanicalin Miyagi and Fukushima Prefectures include theElectrical“compaction degree of 90% for roadbed” ((hereinafterreferred to as the road standard), indicating that thecompaction degree under the road standard has been

0%

20%

40%

60%

80%

100%

secured (Figure 3.3.2.11).

Damage rate

Figure 3.3.2.9 Relationship between Depths ofAnti-liquefaction
measures
液状化対策

Road
construction
道路土工

Tsunami-caused Floods and Degrees of Damage byType of Facilities (pumping stations)

路 盤
Subbase
90％以上
90% or more

路 床Roadbed(4) Anti-liquefaction measures for sewer pipe facilities
85% or more
85％以上(90%以上)

and their effects

路 体(90% or more)

Anti-liquefaction measures for sewer pipe facilities

Sewer

下水道管
pipe

are described in “Commentary on the Sewage
SystemEarthquake

90％程度以上
About 90% or

more

90% or more

About 90% or90％程度以上

85% or more
(90% or more)

more

Filled-up ground

1) Anti-liquefaction measures for sewer pipe facilities

TreatmentThis construction

Pavement
舗 装

About 90% or90％程度以上
more

conduit

Failed to beobserved aroundthe sewer pipes

ResistanceCountermeasure Guidelines -- FY 2006 Edition.”*In case of controlling compaction of embankment using RI meter in parentheses

There are three anti-liquefaction measures for sewer

Figure 3.3.2.11 Compaction Standards

pipe conduits -- compaction of backfill soil, backfillingwith crushed stones and solidfication of backfill soil --At some of the sewer pipe conduits at locations

indicated in Figure 3.3.2.10 as proposed urgently by asubjected to compaction under the road standard,

panel on anti-earthquake technologies for sewage

however, damage including roadbed anomalies andfacilities, which was created just after the Niigata

loosening was confirmed. This may be because the

Chuetsu Earthquake (FY 2004).

road standard has been set for the roadbed and filledup ground and failed to be observed for the sewer

Compaction of backfill soil

Backfilling with crushedstones and the likepipe conduit space and backfill soil below the filled-up

Solidification of backfill soil

ground. Therefore, tougher construction controls may
be required for anti-liquefaction measures for sewer
pipe

conduits.

Furthermore,

there

are

many

compaction-related problems, including the generalabsence of space for compaction machines for backfill
soil on both lateral sides of sewer pipes, the possibility
Compaction
degree of 90%
or moreCrushedstoneof over-compaction on the upper side of polyvinyl

Solidification

chlorideFigure 3.3.2.10 Three Backfilling Measures for Sewer

(PVC)

pipes

duringconstruction,anddifficulties in securing the compaction degree of 90%

Pipe Conduits

depending on soil quality problems.

2) Compaction of backfill soil

3) Backfilling with crushed stones

This measure is designed to hold down theThis measure uses crushed stones as a backfilling129

material. Ribbed PVC pipes that can resist crushedstones are mainly used for small-diameter sewer pipe
conduits. When ribbed PVC pipes are installed, soil isreplaced with crushed stones only around the pipes ina conventional way. Under the anti-liquefaction
measure, however, it is important to replace soil withcrushed stones beyond groundwater levels (or for theentire backfill).
In the disaster-hit region, the measure has beenused only for some districts of Kurihara City thatlogged a seismic intensity of 7. The district has asewer pipe conduit that includes locations subject tothe conventional backfilling and the anti-liquefaction
measure. Upon the Great East Japan Earthquake, a

Photo 3.3.2.3 Conventional construction (without any

location subject to the conventional backfilling saw aanti-liquefaction measure)major road surface anomaly making vehicle traffic
impossible (Photo 3.3.2.3). At locations subjected tothe anti-liquefaction measure, damage was limited toa slight surface subsidence (Photos 3.3.2.4-5),
confirming the effect of the anti-liquefaction measure.
But slight damage including loosening and roadsurface anomalies was seen for a sewer pipe conduit(about 20 meters) subjected to the anti-liquefaction
measure, prompting us to investigate the causes ofsuch damage. In the investigation, we reviewed
relevant construction documents and interviewed
people in charge of the conduit construction. As aresult, we suspected that there were problems withcrushed stones and sheet pile removal during

Photo 3.3.2.4 Construction subjected to the anti-

construction. Although the anti-earthquake guidelines

liquefaction measure (no damage)recommend a 10% particle diameter (D10) at 1
millimeter or more for a highly permeable material, theD10 for the crushed stones used at the location was
600 micrometers or more. Many fine particles were
included in the crushed stones used there. Therefore,
we suspected that the excess pore water pressure
reduction effect upon the liquefaction declined,leading to the damage. When sheet piles were
removed, voids might have emerged in the groundand backfill, loosening the compacted backfill, as
indicated by the people in charge of the construction.

Photo 3.3.2.5 Construction subjected to the antiliquefaction measure (slight damage)1304) Solidfication of backfill soil

quality survey and a damage analysis conducted for(a) Analysis on Damage Causes in Kurihara

the damaged portions to find damage causes. In the

The earthquake damaged 54 meters out of a totalsoil quality survey, we conducted standard penetration

2,500 meters of sewer pipe conduits subjected toand uniaxial compressive strength tests at a damaged

cement-based solidification of backfill soil in Kurihara.

location and an undamaged one. A calcium oxide

The damaged part was in Uguisuzawa, where soil

analysis was also implemented to estimate theimproved when a cement fixation agent was used for

cement mixing ratio. As a result, the uniaxial

restoring a sewer pipe conduit damaged by the Iwate-compressive strength test found the average uniaxial

Miyagi Inland Earthquake. The damage was limited tocompressive strength per cross section surface

loosening and joint disconnections at a sewer pipe

slipping below the standard levels (50 to 100

conduit subjected to backfill soil solidification, notkilopascals) at both locations, as shown in Table

going so far as to block sewage flow. At some

3.3.2.1. Particularly, no compressive strength was

manholes subjected to backfill soil solidfication,

seen for deeper soil. N-values at the two locations

however, 4-to-11-centimeter uplifts were found. These

were similar. The cement mixing ratio was confirmed

uplifts were similar to the 5-to-10-centimeter uplifts

as close to the level for premixed concrete (50seen in portions that were not subjected to any anti-

kilograms per cubic meter) (Table 3.3.2.2).

liquefaction measure (Photos 3.3.2.6-7).

Interviews with people in charge of construction
implementing the anti-liquefaction measure found that
cement and soil were mixed and churned (by abackhoe three times) at the construction site and thatthe mixture was left untouched for around one day
after churning. Portions for backfill soil solidification
were limited to those where troubles were found. The
solidification failed to cover the entire span or thewhole manhole circumference. As a result, thedamage focused on portions that the solidification
failed to cover.
The above results lead us to suspect that while the

Photo 3.3.2.6 Conventional construction (without any

cement mixing ratio was sufficient, appropriate

anti-liquefaction measure)strength failed to be secured due to backfilling
procedure problems.
A technical study committee on anti-earthquake
measures for sewage systems, created after the
Niigata Chuetsu-oki Earthquake, proposed notes forbackfillingusing

cement-basedsolidification.

A

comparison of these notes, on-site soil quality test
results

andbackfilling

conditions

indicates

thefollowing causes for the failure:・Solidification was limited to problematic parts, failingto produce sufficient effects.
・While cement and soil were mixed and churned
Photo 3.3.2.7 A portion subjected to the anti-

three times by a backhoe at the construction site,liquefaction measure (damaged part)insufficient churning resulted in mixed strengths.
・ The

We here would like to discuss the results of a soil

churnedcement-soil

mixturewas

left

untouched (for about one day), failing to achieve131sufficient strength.

surface compaction around pipes was insufficient.

・ Weak strengths in deep portions indicate that

Table 3.3.2.1 Uniaxial Compressive Strength Test Results in Kurihara City
DamagedTested depth
1.8～2.75 ｍ
2.75～3.35 ｍ
Average per
cross section

Undamaged

Tested depth

Hole No. 1
76 kpa12.6 kpa

Hole No. 2
68 kpa12.2 kpa

44.3kpa

40.1kpa

1.5～2.3 ｍ
2.6～3.54 ｍ
Average per
cross section

Hole No. 3
42.5 kpa
12.6 kpa

Hole No. 4
18.4 kpa
11.4 kpa

27.6kpa

14.9kpa

Average by
depth
51.2 kpa
12.2 kpa
31.7kpa

Table 3.3.2.2 Soil Quality Survey Results in Kurihara City
Survey namePenetration
test(JGS1443)

DamagedHole No. 1

Undamaged

Hole No. 2

Upper
portion: 5
Lower
portion: 5Hole No. 3

Hole No. 4

Upper
portion: 6
Lower
portion: 8Upper portion: 4
Lower portion: 13

Upper portion: 7
Lower portion: 8Upper portion:
Upper portion:
Estimated cement volume=－
Estimated cement volume=
Calcium oxide
38.7kg/m3
69.4kg/m3
analysisLower portion:
Lower portion:(JISR5202)－
Estimated cement volume=－
Estimated cement volume=
43.9kg/m3
34.5kg/m3*Upper portion: Tests were conducted at depths of 1.8 to 2.75 meters below ground level for holes at damaged sites
and 1.5 to 2.3 meters below ground level for holes at undamaged sites.
*Lower portion: Tests were conducted at depths of 2.75 to 3.35 meters below ground level for holes at damaged sites
and 2.6 to 3.54 meters below ground level for holes at undamaged sites.
*Calcium oxide analysis results include a cement content (%) on a dried basis measured through the analysis and acement content estimated based on a dry density of soil obtained through the soil quality survey.
－

Table 3.3.2.3 Solidification and Disaster Recovery Distances by Fiscal Year
Sewagetreatment
districtFiscal Year forconstruction

Omagari Minami District

Solidification
distance (m)Omagari Kita District

Total

Solidification
distance (m)Disasterrecovery
distance(m)

Damagerate (%)

Solidification
distance (m)Disasterrecovery
distance(m)

Damagerate (%)

-

2,742

8

0.29

2,742

9

0.29

Disasterrecovery
distance(m)

Damagerate (%)-

FY 2004

0

FY 2005

3,238

243

7.49

2,453

52

2.12

5,690

294

5.18

FY 2006

3,104

0

0.00

2,095

0

0.00

5,201

0

0.00

FY 2007

3,769

41

1.10

2,114

0

0.00

5,883

41

0.71

FY 2008

2,256

0

0.00

0

-

-

2,256

0

0.00

FY 2009

632

0

0.00

0

-

-

632

0

0.00

Total

12,999

284

2.18

9,405

60

0.64

22,404344

1.54

Solidification
distance (fromFY 2005)

12,999

284

2.18

6,663

52

0.78

19,662336

1.71(b) Damage in Higashi Matsushima City

damage rate came to 5.2% at locations subjected to

Higashi Matsushima City has implemented thethe solidification in FY 2005 and 0.0 to 0.7% at thosecement-based backfill solidification as an anti-

subjected to the solidification between FY 2006 andliquefaction measure since FY 2005 (Table 3.3.2.3). A

2009. Damage thus focused on locations solidified indetailed analysis of damaged locations found that the

FY 2005. In interviews, people in charge of the132solidification said that solidification management

Nationalguidance was insufficient in FY 2005 when the anti-

Management, the director of the Water Quality Control

earthquake

some

Department took part in the committee as a special

improvements including checks on advanced cement

member. At the National Institute for Land andmixing and proper instructions were implemented in

Infrastructure Management, sewage researchers andand after FY 2006. In these improvements inthe Wastewater System Division took the leadershipsolidification management, considerations were given

in operating the committee’s secretariat to coordinate

to the following points:

topics for consideration at the committee, analyze- Checks on on-site cement mixing (implemented on

factors behind disaster damage and give technicalall cement used for mixing)

considerations to recovery measures.

project

startedandthat- A uniaxial compressive strength test was conductedInstitute

for

Land

and

Infrastructure

The committee compiled and published technicalfor each soil sample (at three points for each

proposals

solidification location) to determine the cement volume

technical challenges involving emergency responses,

for mixing.

stopgap recovery and full-fledged recovery. Table

andrecoveryguidelines

addressing

3.3.2.5 shows the chronology of the committee’s(5) Recovery measuresdeliberations. As the committee’s final report, the1) Study committee for earthquake and tsunami

Ministry of Land, Infrastructure, Transport andcountermeasure techniques in sewage systems

Tourism released the “Report of Study committee for

In order to implement stopgap recovery of sewage

earthquake and tsunami countermeasure techniques

facilitiesJapan

in sewage systems -- An Overview of sewage

Earthquake and full-fledged recovery for disastersystems damage by the Great East Japan Earthquake

prevention purposes, the Japan Sewage Works

and Desirable Future Earthquake and Tsunami

Association and the Ministry of Land, Infrastructure,

Countermeasures Based on the Present Situation” on

Transport and Tourism created a Study committee for

May 18, 2012.

damaged

by

the

Great

East

earthquake and tsunami countermeasure techniques

In damaged areas, full-fledged recovery is going onin sewage systems including academic experts listed

based on these proposals.

in Table 3.3.2.4, on April 12, one month after theearthquake.
The committee also included administrative sector
members and special members from the ministry and
the Japan Sewage Works Association. From the133Table 3.3.2.4 Members of the Study committee for earthquake and tsunami countermeasure techniques insewage systems
Chairman: Masanori Hamada, Professor, Department of Civil and Environmental
Engineering, Faculty of Science and Engineering, Waseda University
Academic expert members:
Fumihiko Imamura, Professor, Disaster Control Research Center, Graduate School ofEngineering, Tohoku University
Tatsuo Omura, Professor, Department of Civil and Environmental Engineering, Graduate
School of Engineering, Tohoku University
Itsuki Nakabayashi, Professor, Graduate School of Political Science and Economics,
Meiji University
Mitsunobu Nomura, Director, Technology & Strategy Department, Japan Sewage Works
AgencyKoji Fujima, Professor, Department of Civil and Environmental Engineering, School of
Systems Engineering, National Defense Academy of Japan
Yasutaka Fujimoto, Associate Professor, Department of Electrical and Computer
Engineering, Yokohama National University
Osamu Matsuo, Director, Utilization Promotion Department, Advanced Construction
Technology Center
Susumu Yasuda, Professor, Division of Architectural, Civil and Environmental
Engineering, School of Science and Engineering, Tokyo Denki University
Table 3.3.2.5 Chronology of Deliberations at the Study committee for earthquake and tsunami countermeasuretechniques in sewage systems
Date
April 12, 2011

Committee meeting,etc.
1st meeting

April 15

Releasinganemergency technicalproposal on sewage
facility recovery (1stproposal)

May 24

2nd meeting

June 13

Releasing desirable
gradualstopgap
recovery measures(2nd proposal)

July 19
August 11

3rd meeting
Releasing desirable
recovery of sewage
facilities damagedby the Great East
Japan Earthquake(3rd proposal)

Topics/technical support
・Damage to sewage facilities and recovery/support
・Technical challenges regarding recovery
The proposal compiled approaches on securing public health, on
emergency anti-flood measures for the flood season and on recovering
sewage facilities, and was sent by the Ministry of Land, Infrastructure,
Transport and Tourism to the governments of disaster-damaged
prefectures and designated major cities as a notice from the Planning
Officer of the Sewerage Works Division at the ministry’s Sewerage andWastewater Management Department.
・Damage and recovery conditions
・Desirable gradual stopgap recovery measures
・Desirable measures to promptly secure public healthThe proposal compiled basic guidelines to gradually improve the quality of
released water by implementing stopgap recovery measures according to
the periods of time before full-fledged recovery, and was sent by the
Ministry of Land, Infrastructure, Transport and Tourism to the governmentsof disaster-damaged prefectures and designated major cities as a noticefrom the Planning Officer of the Sewerage Works Division at the ministry’s
Sewerage and Wastewater Management Department.
・Desirable full-fledged recovery of disaster-damaged sewage facilities
The proposal compiled basic policies on the full-fledged recovery of
sewage facilities, policies on anti-tsunami measures in the full-fledged
recovery, policies on measures addressing ground changes throughliquefaction in the full-fledged recovery and other matters of concern, andwas sent by the Ministry of Land, Infrastructure, Transport and Tourism to
the governments of disaster-damaged prefectures and designated major
cities as a notice from the Planning Officer of the Sewerage Works Division134

October 17

4th meeting

December 15

5th meeting

February 24,
2012

6th meeting

March 6

Releasingapproachesonsewagefacility
designs taking antitsunami measures
into account (4thproposal)
7th meeting

March 22

May 18

Releasing the reportby the TechnicalStudy Committee on
AntiEarthquake/Tsunami
Measuresfor
Sewage Facilities

at the ministry’s Sewerage and Wastewater Management Department.
・Recovery responses just after the Great East Japan Earthquake anddesirable BCPs
・ Recovery responses and challenges after the Great East Japan
Earthquake
・ Wide-area support conditions regarding the Great East Japan
Earthquake
・Reports on specific general ground liquefaction damage cases, etc.
・Overview of sewage facility damage through the Great East Japan
Earthquake
・Time schedules for recovering sewage facilities
・Approaches on sewage facility designs taking anti-tsunami measures
into account・Overview of sewage facility damage
・Approaches on sewage facility designs taking anti-tsunami measures
into account・Desirable guidelines for sewage facilities, etc.
Based on damage through the Great East Japan Earthquake, the proposal
compiled approaches to be applied to sewage facilities in areas where
massive earthquakes are expected to cause large-scale tsunamis. It wassent by the Ministry of Land, Infrastructure, Transport and Tourism to thegovernments of disaster-damaged prefectures and designated major cities
as a notice from the Planning Officer of the Sewerage Works Division at
the ministry’s Sewerage and Wastewater Management Department.
・Disaster prevention and reduction targets for improving earthquake andtsunami protection
・ Draft final report by the Technical Study Committee on AntiEarthquake/Tsunami Measures for Sewage Facilities
The committee compiled and published the “Report by the Technical Study
Committee on Anti-Earthquake/Tsunami Measures for Sewage Facilities -An Overview of Sewage Facility Damage by the Great East Japan
Earthquake and Desirable Future Anti-Earthquake/Tsunami Measures
Based on the Present Situation.”

Following are new viewpoints for future anti-

scattered and promoting sewage BCPs thatearthquake/tsunami measures as indicated by theassume sewage spills from sewer pipe bridges andcommittee’s final report:

the submersion of switchboards for manhole pumps.
・Anti-tsunami measures for sewage treatment plants(a) Anti-earthquake measures for sewer pipe facilities

and・Anti-liquefaction measures for the backfill shouldmeasures including the adoption of concrete caps

include the consideration of construction work

for waterproof purposes for facilities and equipment

management problems and their solutions and theandexpansion of manuals and the like to improve

preventing gas holders and the like from flowing out,

technical understanding on construction methods.

and the adoption of facility structures giving

・ Anti-liquefaction

measuresforthegroundpumping stations

for

their

shouldearly recovery,

cover

gradualmeasuresfor

considerations to tsunami loads and directions.

surrounding sewer pipes should include thedevelopmentoftechnologies

forpreventing(c) New reconstruction efforts
・The full-fledged recovery of sewage facilities should

manhole shifts and sediment inflow through joints.

positively introduce technologies suitable for hopeful(b) Anti-tsunami measures for sewer pipes, sewage

reconstruction in the 21st century and systems thattreatment plants and pumping stations

can contribute to regional communities.

・ Anti-tsunami measures for sewer pipes should・A reconstruction scheme study panel should be

include preventing manhole caps from being

created to conduct a feasibility study on model

135

projects in Kesennuma and Sendai Cities, based on

development

not only technical knowledge but also the viewpoint

earthquake/tsunami measures.

measurestopromoteanti-

of contributions to reconstruction/town-building andthe distribution of renewable resources and energy.

b) Disaster prevention targets to improve antiearthquake/tsunami performances
・Short-, medium- and long-term targets should be(d) Present conditions and challenges of antiearthquake/tsunami measuresestablished according to the necessity and urgency

・ While promoting anti-earthquake measures forof sewage facility functions upon earthquakes or

sewage facilities including the enhancement oftsunamis in order to gradually enhance anti-

these facilities’ quakeproof performances andearthquake/tsunami

systematic measures, many local governments

facilities.

・ A questionnaire survey indicates that few antitsunami measures have been implemented.
additiontoexisting

should include the enhancement of tsunami-proof
performances for the backflow prevention functions

・Urgent challenges include launching anti-tsunami
inof・ Short-term targets for anti-tsunami measures

have failed to make smooth progress.

measuresperformances

promotingof pipe facilities and the pumping functions ofthepumping stations and sewage treatment plants

enhancement of existing facilities’ quakeproof

whose stoppage would result in massive damage,performances.

as well as the development of evacuation and otherfacilities required for securing human lives.

(e)

Basic

approaches

onpromotinganti-earthquake/tsunami measuresc) Disaster reduction targets to improve anti-a) Basic approaches

earthquake/tsunami performances

・ Basic approaches include the “prevention of・ Anti-earthquake/tsunami measures

should bedisasters” through the enhancement of structural

based

the

enhancement

anti-earthquake/tsunami performances and theearthquake/tsunami

performances“reduction of disasters” to minimize impacts on

facilities under disaster prevention targets. In order

citizens’ daily life.

to secure immediate tentative responses to achieve

on

of
of

antisewage

・A priority order should be specified for measures

minimum objectives when disasters come before

according to the necessity and urgency of sewage

such measures are completed, however, short- andfacility functions. Most feasible measures should be

medium-term

followed by less feasible ones to gradually enhancebasically through the preparation of sewage systemsewage facilities’ anti-earthquake performances.

BCPs according to the gradual improvements of・New anti-tsunami technical standards should betargets

shouldbeestablishedfacilities.

considered. Under the anti-tsunami community

・ Short-term targets for anti-tsunami measuresbuilding law, anti-tsunami measures should beshould include the early preparation of sewage

implemented

inundation

system BCPs, the stockpiling of portable pumps

assumptions” that prefectural governors establish

and power generators for regular training and floodand publish with the maximum projected tsunami

damage reduction, and the establishment of

taken into account.

channels for their procurement upon disasters.

based

on

“tsunami・ The preparation of sewage facility BCPs tominimize social impacts of damage to sewage(f) Challenges and desirable concept of guidelines forfacilities and achieve their prompt recovery should

anti-earthquake measures for sewage facilities

be launched. Software measures including the・Anti-liquefaction measures for branch pipes andpreparation of disaster assistance rules should be

how to prevent manholes’ lateral shifts should be

expandedconsidered. Guidelines should be expanded andandcombinedwithhardware136

enhanced to include key points of construction work20, 2011, created the Study Committee on Sewage

management for the three backfilling measures andSystem BCP Manual (for earthquakes and tsunamis) ,new backfill materials.

comprising academic experts and others as listed in・Detailed facility design methods for anti-tsunami

Table 3.3.2.6.

measures should be considered along with how toTable

3.3.2.7

indicatesthechronologyof

set a priority order for facilities subject to anti-deliberations at the committee. As its final report, thetsunami measures.

“Study Committee on Sewage System BCP Manual(for earthquakes and tsunamis)”, was published by the2) Study Committee on Sewage System BCP Manual

Ministry of Land, Infrastructure, Transport and(for earthquakes and tsunamis)

Tourism on April 2, 2012. In not only disaster-In order to share experiences and lessons from thedamaged areas but also other areas, sewage system

Great East Japan Earthquake and recover sewage

BCPs are being worked out based on this manual.

functions upon disasters for maintaining regional

Figure 3.3.2.12 indicates the flow of sewage systempublic health environments, the Ministry of Land,

BCP preparation procedures given in the committee’s

Infrastructure, Transport and Tourism on December

final report.

Table 3.3.2.6 Members of the Study Committee on Sewage System BCP Manual (for earthquakes andtsunamis)＜Experts＞
Chairman: Itsuki Nakabayashi, Professor, Graduate School of Political Science andEconomics, Meiji University
Koji Fujima, Professor, Department of Civil and Environmental Engineering,
School of Systems Engineering, National Defense Academy of Japan
Yoshiyuki Tsuji, Chief Researcher, Science and Safety Research Division,
Mitsubishi Research Institute, Inc.
＜Administration experts＞
Keiji Sugawara, Chief, Sewage Division, Civil Engineering Department, Miyagi
Prefecture Government
Shozo Shibuya, Deputy Director and Director, Sewage Department, Construction
Bureau, Sendai City Government
Toshiyuki Nagamine, Director, Urban Environment Department, Urayasu City
Government
Shigeyuki Horoiwa, Chief, Planning Division, Planning and Coordination Department,
Bureau of Sewerage, Tokyo Metropolitan Government
Satoshi Yamamoto, Director, Western Area Management Office, Construction Bureau,
Osaka City Government
Keisuke Hata, Director, Sewage and River Department, Construction Bureau, Kobe
City Government＜Relevant organizations＞
Yasuhiro Shinoda, Director, Japan Sewer Collection System Maintenance Association
Go Saeki, Executive Director and Technology Department Chief, Japan Sewage Works
Association
Ichiro Kobayashi, Managing Director, Japan Sewage Treatment Plant Constructors
Association

137

Table 3.3.2.7 Chronology of Deliberations at the Study Committee on Sewage System BCP Manual (forearthquakes and tsunamis)
Date
December 20,

Topics/technical support

Meeting
1st meeting

2011

・Conditions and challenges of recovery responses after theGreat East Japan Earthquake
・Desirable sewage system BCPs based on the Great East
Japan Earthquake caseFebruary 1,

2nd meeting・Direction of manual revision
・ Tsunami damage caused by the Great East Japan2012

Earthquake and projection methods
・Damage projections covered by sewage system BCPs
・Notes on reporting recovery response cases and preparing
sewage system BCPs
February 29

3rd meeting

・Revised manual draft138

[Development example] Chapter 1

Development and Operation System (§6 in
Chapter 2)[Development example] Chapter 2

Organization of fundamental items (§7 in Chapter 2)･ Securement of a handling post in a time of disaster･ Securement of emergency contact with important affiliates･ Confirmation of stock of daily goods and holding materials
and equipment[Development example] Chapter 6
Establishment of earthquake scale and damage
projections (§8 &9 in Chapter 2)

Selection of priority works (§10 in Chapter 2)

 Establishment of earthquake scale and the like･ Earthquake scale: Seismic intensity of 6
･ Tsunami: the maximum projected class･ Date and time of occurrence: During office hours and nights and holidays
 Damage projection･ Sewer pipe: (ex.) ○% of function stoppage in total length･ Lifeline: (ex.) ○days blackout at governmental offices and treatment

 Selection of priority operations (alternatives) in the event of an
occurrence
1) Handling operation against disasters
Safety confirmation of officials, liaison and coordination with
relevant administrative sections and private firms, emergency
checkup, emergency investigation, appeal for assistance,collection and dispatch of information about disaster condition,
resolution of flood and overflow stream etc.
2) Routine operation
Operation control of non-devastated treatment plants and so on

facilities･ Treatment facility: (ex.) Function stoppage due to a lack of anti-earthquake
measures to sedimentation tanks･ Officials: (ex.) ○% of officials who would be possible to gather in ○hours

Figuring out acceptable downtime (§11 in Chapter 2)
Consider social impacts and the like in case of a delay incompleting a priority operation (alternative) and figure out therough time (acceptable downtime) to complete

Determination of target time to respond (§12 in
Chapter 2)

Examination of

measures forTarget time by which the priority operation can be completed
challenges
almost certainly. Considering current resource restrictions,determine “the target time to respond” taking into account the
Reflect the
preliminary measures that have been conducted by the time of measurescompletion to prepare sewage facility BCPs in addition to the
conducted
target time by which the priority operation can be completed
almost certainly (current available response time)

Select the work
considering “target
time for response”[Development example] Chapter 3 - 5
Plan for training, maintenanceand improvement (§23 & 24 in
Chapter 5)
Those showing secure
implementation of the emergency
response plan, training to establish
the sewage facility BCPs and theirmaintenance and improvement

Training of
response
procedureEmergency response plan (§14
in Chapter 3)
Those showing the response
procedures through time after thedisaster occurrence based on resource
restrictions.

Reflecting
themeasures
implemented

Plan for preliminary measures(§15-22 in Chapter 4)Those showing measures to prompt“target time for response” and“current available response time”
e.g.
Maintenance of sewerage ledger
Securing materials and equipment(stockpiling and procurement)
Coordination with relating
administrative sections etc

Reviewing the response
procedures for challenges
Examining the measures for challenges

Figure 3.3.2.12 Flow of Sewage System BCP Preparation Procedures

139

3)

Committee

toreviewcountermeasuresongovernments and special members from the Ministryradioactive material pollution in sewage systemsof Land, Infrastructure, Transport and Tourism and the

In order to appropriately maintain the functions ofJapan Sewage Works Association. At the National

sewage facilities indispensable as part of lifelines, theInstitute for Land and Infrastructure Management,

Sewerage and Wastewater Management Department

sewage researchers and the Wastewater Systemat the Ministry of Land, Infrastructure, Transport andDivision took the leadership in operating the panel’s

Tourism

reviewsecretariat to conduct a fact-finding survey and acountermeasures on radioactive material pollution intechnical analysis on the behaviors of radioactive

sewage systems” comprising academic experts andsubstances.

createdthe“Committee

toothers as listed in Table 3.3.2.8. The panel accurately

The panel accumulated deliberations as indicated ingrasped the conditions of damage caused by

Table 3.3.2.9. As its interim report, the Ministry ofradioactive substances and compiled opinions from

Land, Infrastructure, Transport and Tourism publishedexperts in various fields on future responses thatthe “Interim Compilation of Deliberations at the

sewage facility managers should take based on

Committee to review countermeasures on radioactive

notifications and the like from the Nuclear Emergency

material pollution in sewage systems” on November

Response Headquarters.

25, 2011. The report made the following key points on

The panel includes not only the abovementioned

measures against radioactive substances at sewage

academic experts but also members from local

facilities:

Table 3.3.2.8 Panel Members (in random order with honorifics omitted) (as of May 28, 2012)
Chairman

Tetsuya Kusuda

Professor,

FacultyofEnvironmental

Engineering,Member

Hideo Kimura

Senior Researcher, Waste Safety Research Group,

University of Kitakyushu

Nuclear Safety Research Center, Japan Atomic Energy
Agency〃Hiroyasu Satoh

Associate

Professor,

Graduate

Schoolof

Frontier

Sciences, University of Tokyo〃

Yutaka Suzuki

Leader, Materials and Resources Research Group,
Public Works Research Institute〃

Masaki Takaoka

Professor, Graduate School of Engineering, Kyoto〃

Hiroyuki Fujimoto

Director for Technical Development and International

University

Office Chief, Japan Sewage Works Agency〃

Yuichi Moriguchi

Professor, Department of Urban Engineering, Graduate
School of Engineering, University of Tokyo〃

Shinsuke Morisawa

Professor, Center for iPS Cell Research and Application,
Kyoto University〃

Hirokuni Yamanishi

Associate Professor, No. 3 Research Office, Kinki
University Atomic Energy Research InstituteSpecial member

Mitsuhiro Kurozumi

Director, Planning and Coordination Department, Bureauof Sewerage, Tokyo Metropolitan Government〃

Shinichi Nagasawa

Chief, Sewage Division, Civil Engineering Department,
Fukushima Prefecture Government140

Former member

Hitoshi Nakazawa

Director for Technical Development and International
Office Chief, Japan Sewage Works Agency〃

Nobuyuki Sugiura

Director, Research Center for Radiation Emergency
Medicine, National Institute of Radiological Sciences

Former special member Masayuki Matsuura

Director, River-Basin Sewage Headquarters, Bureau of
Sewerage, Tokyo Metropolitan Government〃

Yoshihiro Narita

Chief, Sewage Division, Civil Engineering Department,
Fukushima Prefecture Government

Table 3.3.2.9 Chronology of Panel Deliberations
Date
June 17, 2011

Meeting

Topics

1st meeting

Figuring out radioactive substances found in sewage
sludge, future topics, etc.

July 25

2nd meeting

Environments

aroundsewagetreatment

plants,radioactive substances’ behaviors at sewage treatment
plants, etc.
August 29

3rd meetingRadioactive substances’ behaviors, how to store highly
radioactive sewage, etc.

October 4・ Guideline for methods for disposal of incinerated

4th meeting

sewage ash with radioactivity density readings ranging
from above 8,000 becquerels per kilogram to 100,000
Bq/kg

・Interim compilation draft, etc.
November 16・ Interim compilation draft, surveys under the third

5th meeting

supplementary budget for FY 2011, etc.
May 28, 2012

・ Report on fact-finding surveys under the third

6th meeting

supplementary budget for FY 2011, etc.
(a) Challenges and responses regarding sewage

information service

sludge with radioactive substances foundA questionnaire survey of local governments on

Radioactive substances have been widely detected

sewage sludge storage and radioactivity monitoringin environments mainly in the Kanto and Tohoku

conditions, how to secure the safety of residents

regions. At a wide range of sewage treatment plants,

surrounding storages, desirable information service

radioactive substances have been detected in sewage

and other problems has been conducted, confirming

sludge. But radioactivity density readings have beenthat sludge containers have been enclosed to prevent

declining and are expected to decline in the future. But

sludge from scattering and covered with liner sheets

the effective utilization or disposal of sewage sludge

to prevent rain water from permeating into sludge,

has been suspended, leading sewage sludge stocks

securing safety appropriately. But the survey has

to increase. Measures are urgently required to securefound that sludge smells and other problems havefacilities for accepting and storing sludge and to

been emerging as sludge has been stored long.

reduce sludge volume.

Radioactivity monitoring has been done with sludge
radionuclide analyses and steady air radiation(b)

Situation

includingregardingradioactive

storedsewagesludgemeasurement at borders with sewage treatment plant

substancesandrelevantsites, securing safety for residents surrounding these141plants. Radioactivity density readings have been well

90 Bq/L for Cesium 137, their percentage shares’

informed to citizens through websites and briefings.

combination at 1 or less). No radioactive substances

Efforts meeting regional characteristics (including

were detected in exhaust gas from sludge incineration

residents’ participation in radiation measurement)

facilities.

have also been made. The panel’s interim compilationofdeliberations

proposed

specific

Tests using incinerated sewage sludge ash andappropriate

melted slag to elute radioactive substances confirmed

information provision measures in an orderly mannerthat little such substance was eluted even uponbased on actual information service cases.

water’s contact with the ash and slag.
These results indicated that radioactive cesium(c) Radioactive substances’ behaviors related toshifted mainly to sludge and that appropriate sludge

sewage facilities

disposal would be the most important (Figure

A survey on radioactive substances’ flow into

3.3.2.13).

sewage treatment plants has been conducted,
confirming that massive radioactive substances flew(d) Storing sewage sludge containing massive

into combined sewage systems upon rainfall. An

radioactive substances

analysis of radioactive substances’ behaviors within

Based on an approach on immediate handling of

sewage treatment plants indicated that radioactive

water and sewage treatment by-products found to

substances are accumulated mainly in air ration tanks

include radioactive substances, as notified by theat these plants and enriched through sludge

Nuclear Emergency Response Headquarters on June

condensation, dehydration and other processes.

16, the panel considered specific future measures forRadioactive substances, though circulating withinstoring sewage sludge including massive radioactive

sewage systems through returned water, have tended

substances and for prolonging storage duration.

to decline through a fall in their inflow into the systems

The panel concluded that flexible containers canand sludge removal. Radioactivity density readings forusually be used for storing sewage sludge and that if

dehydrated sludge have tended to decline over a longcontainers are required to be piled up high at a small

time.

storage site, flexible containers may be put into 20-

Radioactive substances have not been detected infeet containers or 200-liter drum cans may be usedmost of the released water. Even when radioactive

instead of flexible containers.

substances were found in released water, theirdensity readings slipped far below the maximum
allowable density in water (60 Bq/L for Cesium 134,

Cs is mainly accumulated in air ration tanks → Declining over along timeCs

Circulating part of Cs
through returned waterand the like

Cs

Primary
sedimentation
tank

Cs

SludgeInflow water
Returned water

Cs inflow due torainfall and thelike →
Declining over along time

Air ration
Cs tank Cs
Cs Cs

Not detected in most cases
Below the maximum allowabledensity in water when detected

Final
sedimentationtank

combination at 1 or lessReleased water

Cs

Exhaust gas
Cs is condensed through sludge treatment process
Condensed sludge

Condensation
tank

Cs
Cs Cs

Dehydration
machineDensity in water･ Cs-134: 60 Bq/L, Cs-137: 90 Bq/L･ Their percentage shares’
Cs is not detected inexhaust gases fromincinerators, etc. nor emitted
in the environment

Incineration Incineratied ash
facility
Cs
Cs Treatment and the like
Melted slag Cs
facility
With a tendency of Cs in
incinerated ash and melted slag
*Cs: Radioactive cesium not easily eluted

Dehydrated sludge

Cs
CsCs

Figure 3.3.2.13 Image of Radioactive Cesium’s Behaviors in Sewage Treatment Processes

142

Dehydrated sludge

Effective radiation level [μSv/h]of radioactive wastes and their surface radiation levels

Plain view frame format

Flexible container accumulation (2m×50m×2m)

and rates should be recorded and managed rationallyon a lot basis.

Isolation distance from the surface of dehydrated sludge [m](3) Methods to reduce sewage sludge volume

Example of results of radiation level evaluation
 Examination condition

The panel concluded that sludge volume reduction

・ Radioactive cesium concentration in dehydrated sludge =100,000Bq/kg
・ Without ceiling

methods(drying,carbonizing,

incinerating

andmelting) should be selected with considerations given
Without shielding

to their respective characteristics, their key points andConcrete thickness 10 cm

evaluation viewpoints when hydrated sludge storage
and volume reduction facilities are introduced. Drying

Concrete thickness 20 cm

equipment installation requires less time and mobile
dryer vehicles can be used tentatively. It may thus be

Isolation distance from the surface of dehydrated sludge [m]easy to introduce such equipment. But it should be
noted that organic matters may still be left even after【Specific case for radiation shielding evaluation results】

drying.

In the case of flexible container accumulation（2 m × 50 m × 2

While sludge volume reduction is useful for securingm）and the radioactivity density of 100,000 Bq/kg for storage, anysites for long-term sludge storage, it should be notedof the following measures can reduce workers ’ radiationthat radioactive cesium in sewage sludge can be

exposure to 1 microsieverts per hour or lessenriched through sludge volume reduction. Therefore,

・Maintaining an isolation distance at 10 meters or moremeasures should be implemented securely to prevent・Shielding radiation with a 20-centimter or thicker concrete wall

radioactive cesium from scattering and relevant

・Shielding radiation with a 5-centimeter or thicker steel plate

workers from being exposed to radiation.

Figure 3.3.2.14 Effects of Isolation Distance andShielding Regarding Effective Radiation Levels

4) Responses to disaster support liaison conferences
In addressing the expected great Nankai TroughOn blocking radiation, we computed specific effects

earthquake, the National Institute for Land andof shielding with concrete structures and isolation

Infrastructure

distances for reducing radiation exposure andearthquake measures and implemented the report byillustrated the results in an easy-to-understandthe abovementioned Study committee for earthquake

manner (Figure 3.3.2.14).

and tsunami countermeasure techniques in sewage

Specific appropriate radiation surveillance methods

Management

has

promotedanti-systems At disaster support liaison conferences, theinclude measuring radioactivity density in dehydrated

institute reported

sludge and the like regularly and after rainfall,targets for anti-liquefaction and anti-tsunami measures.

monitoring air radiation rates at work areas and・July 10, 2012: 18th Chugoku/Shikoku Block Liaison

borders with sewage system sites, checking radiation

Conference on Disaster Support

with personal passive dosimeters, and confirming that・ August 9, 2012: FY 2012 Kanto Block Liaison

the radiation density in exhaust gas at incineration

Conference on Disaster Support

facilities slips below the maximum allowable density in・August 24, 2012: FY 2012 Chubu Block Liaison

33

approaches

anddevelopment

air (20 Bq/m for Cesium 134, 30 Bq/m for Cesium

Conference on Sewage Disaster Support

137, their percentage shares’ combination at 1 or less).

・August 30, 2012: FY 2012 Hokkaido/Tohoku Block

As for sludge including radioactive substances,

Liaison Conference on Sewage Disaster Support

appropriate management arrangements must be・ September 4, 2012: 19th Kinki Block Support

developed under an assumption that such sludge may

Liaison Conference on Sewage Disaster

have to be stored over a long time. To this end, types

・ October 11, 2012: FY 2012 Kyushu/Yamaguchi

143

Block Liaison Conference on Sewage Disastertsunami countermeasure techniques in sewage

Support Arrangements

systems
http://www.mlit.go.jp/mizukokudo/sewerage/crd_s
ewerage_tk_000170-1.html

Useful reference website
1) Report of Study committee for earthquake and144

“Destruction/failure” and “subsidence/sinking/crevice”

3.3.3 River

2)

The National Institute for Land and Infrastructure

account for about 60 percent, stretching over 66km .

Management (NILIM) launched a field survey on the

Failure of levees was limited to at around 2.8kp of the

day after the Great East Japan Earthquake on Marchleft side and around 4.2kp of the right side of the Shin-11, 2011 (hereinafter referred to as the “3.11Kitakami River (installation point of Tsukihama Daini

Earthquake”), and examined river management

Floodgate), the special levee at around 0.2kp of the

facilities, such as levees, to examine the extent ofright side of the Naruse River and at the junction with1)

damage caused by seismic motion and tsunami .

the seawall of the left and right sides of the river-With respect to damage to levees caused by themouth of the Abukuma River. The next largest

tsunami, characteristics of damage were analyzed bydamage after the failure of levees was the damage totype and magnitude of damage, the correspondence

the back slopes of levees and to the protected land atof spatial distribution to longitudinal distribution of

the rear side of the levees due to overflow. Damage tohigh-water level, and relations between the magnitude

the slope caused by the high flow rate of the tsunamiof levee erosion due to overflow and water depth andwas slight.

time period of overflow. The results of the survey were
provided

periodically

Regional

magnitude of the tsunami damage and the external

of

Land,

force at the time of the tsunami uprush, focusing on

Infrastructure and Transport and Tourism (MLIT), andthe erosion of the back slopes of levees and theusedvariousprotected land at the rear side of the levees of thecommittees, mentioned later. The summary is

Abumuma River due to overflow, which was thedescribed in the following section (1).

second largest damage after the failure of levees.

Development
astoBureau,referencethethe

TohokuThis section examines the relations between the

Ministrymaterials

for

the

The following committees on river management

Photo-3.3.3.1 is an aerial photograph near the river-facilities were established in response to the 3.11

mouth of the Abukuma River taken right after thetsunami disaster: “Research Committee on Riverdisaster, which gives zones to show the relations

TsunamiStudy

between the high water level and the crest height andCommittee on Earthquake-proof Measures of Riverdamage to the levee slopes, in accordance with theLevees,”Anti-seismic

following criteria. As for the relations between the highReinforcement Technology for River-mouth Weir andwater level and the crest height, the area was divided

Floodgate based on the Lessons Learned From theinto three zones: submerged zone, overflow zone,

Great East Japan Earthquake,” “Research Committee

and uprush zone below the crest height, using theon Reconstruction Technology for Levees of theresults of field survey and survey on tsunami traces as

Kitakami River, etc.,” and “Research Committee ona reference (see Figure 3.2.2.5). As Table 3.3.3.1

Reconstruction Technology for Levees in Kanto

shows, the damage is classified into four levels in

Region.” An outline and recommendations/reports ofaccordance with the severity. No notable damage wasthese Committees are described in (2) through (6).

incurred in the zones where no damage level was

Countermeasures,”“ResearchCommittee“Urgent
ongiven. The back slopes were not covered with
(1) Characteristics of damage to levees

concrete and herbaceous plants grew thickly.

The number of river management facilities underThe submerged zone was limited to the areas near

the direct control of MILT damaged by the earthquake

the river-mouth, and an overflow zone and uprush

and tsunami was 1195, widely covering from thezone below the crest height appear as it goes

Mabuchi River in the north to upstream of the

upstream. This confirms that the water level receded

Abukuma River in the south. Among 773 damaged

as the tsunami traveled. However, the length of thelevees, severe damages, such as destruction andoverflow zone is greatly different between the left andfailure of levees, are concentrated in the Kitakami

right sides of the bank. While the left bank has aboutRiver, the Naruse River and the Abukuma River.

0.5km in length, it is longer on the right bank with145

about 2km. Except for the river-mouth area, the heightof the tsunami trace exceeded the height of the levee

Table 3.3.3.1 Category of Disaster

Ohashi (bridge), and it is assumed that the height ofDamagelevel
Itsunami waters was high at the right bank where theIIby nearly 5 m at around the right bank of the WatariState of damage
Herbaceous plants are lodged due to the stream, but little
detachment is observed
Partial detachment of plants living on the slope and erosion oflevees in the form of gullies are observed. No or little formation ofpools dug by the stream is observed.
Total erosion and failure of slopes, with vertical planes. It isfollowed by the formation of pools dug by the stream in somecases.
Slope is washed away and erosion and failure have reached to thecrest. It is followed by the formation of pools dug by the stream insome cases.

outer bank of the river bend was hit by the tsunami
III

attack.
In the submerged zones around the river-mouth,IVboth the left and right banks were collapsed where theriver levees are connected with the seawall. Besides
this area, the damage to the left bank was mostly levelI except for the level III damage at around theJudging from the observation that the high water

floodgate at 0.55km point. However, the damage tolevel of the right bank of the Watari Ohashi was higher

the right bank was more severe with damage level III

than that of the downstream, it is estimated that theto IV. The same is observed in the overflow zones; thedamage level corresponds, to some degree, to themagnitude of damage was greatly different between

overflow water depth. However, this alone cannot fully

the right and left banks. Whereas the damage to the

explain the difference in damage level between theleft bank was at level I, that to the right bank was atleft and right banks. On this point, it is assumed thatlevel II and III in a wide area running along about 2km.

erosion of back slopes and toes of slopes was

Furthermore, on the right bank, level I damage was

mitigated by the water cushion effect (Figure 3.3.3.1).

recorded in the 0.8-1.2 km zones and level II/III

This effect is caused either by inundation of protected

damage was incurred as it goes further upstream fromland earlier than the overflow from the river side or bythose zones.

inundation of protected land shortly after the overflow.
The following paragraph provides a quantitative study

Uprush zone below the crest heighton the factors that determine the magnitude ofdisaster, using the results of simulation of the tsunami
3)of 2011 (hereinafter referred to as “simulation result”).
Ⅰ

At initial overflow

Ⅱ

Levee
Body
Riverside

Ⅲ
Ⅱ
D
Ⅲ

High speed stream

Inside the Levee

Strong stream→Progress of erosion

ⅠⅠ(minutes order)

F

Ⅲ

C

Rapid rise
Water cushion

Ⅰ
E Ⅱ

Ⅱ

Riverside

ⅠB

Inside the Levee

Weak stream→Progressing slowly

Ⅲ A
Ⅳ

Figure 3.3.3.1 Image of progress of erosion due to a
rapid rise in water level inside the levee

MetersPhoto 3.3.3.1 Relations between high water level of

Figure 3.3.3.2 shows how the tsunami propagates

the tsunami and height of levees and the extent ofusing the simulation result. The tsunami climbed overdamagethe seawall and spread to the left and right sides with146

nearly the same magnitude. About three minutes after

In

order

to

elaborate

thisphenomenon,

overflowing the seawall, the tsunami stopped at thechronological change in the water level of the riverleft side of the bank but it still progressed up the rightand inside the levee at locations from A through F inside of the bank. At the left side of the bank, the water

Photo-3.3.3.1 were calculated from the simulationlevel rose to about 6m (green area in the legend) atresult, which are shown in Figure 3.3.3.3 together withnearly the same time as the tsunami traveled

the overflow period and damage level. The figures in

upstream. And at the right side of the bank, a low

the brackets next to overflow time, etc. are thewater level area of less than 3m of water level (blueoverflow period and initial overflow period in the unit ofarea in the legend) was observed after the tsunami

seconds. Here, the term ‘overflow period’ refers to thetraveled upstream. At the right side of the bank, wheretime period during which the water level of the river

this alignment of levee moves away from the rightexceeds the levee height. When the water level insidebank as the tsunami travels upstream, overflow

the levee exceeds the water level of the river side, like

continued with a relatively low level of inundation

at the location E, time until that moment is identified

inside the levee, although there is a slight difference inas the overflow period. The initial overflow period isthe duration among zones. An obvious cause of this is

the time period between when the water level of thethe situation in the first three minutes after theriver side exceeds the levee height and when theoverflow of the seawall. In the areas inside the rededge of the levee is inundated to the level where

dotted lines, overflow occurred several minutes before

hydraulic jump of the overflow water almost occurs

the tsunami traveling in the protected land arrived atnear the toe of slope. This is thought to be the level

the edge of the levee.

where the effect of water cushion can be produced.
The overflow period of the location A and location E

Legend -3

3

is almost the same. The maximum overflow water

12 Water level(m)

depth was different: about 6m at the location A andabout 3m at the location E. Still, both figures are large
considering the vulnerability against overflow of levee.
While the initial overflow period at the location A is 6
minutes, that of the location E is zero, which confirmsthat the effect of water cushion occurred at the(1) Right after overflowing the seawalls (2) 1min after over overflowing the seawalls

location E when the overflow started. Therefore, it isfair to conclude that the level of disaster at the location
E was mitigated by the water cushion.

(3) 2min after overflowing the seawalls (4) 3min after overflowing the seawalls

Figure 3.3.3.2 Propagation of tsunami (Aerial
photograph in the background is photographic data of
the Geospatial Information Authority of Japan)

147

Overflow time (400)

A. Abukuma River R0.33kp

Disaster level IV
Initial overflow period (355)

Levee height

Ground level
behind the leveeRiverside water
level
Water level
behind the levee

Altitude Ｔ.Ｐ. (m)Altitude Ｔ.Ｐ. (m)Overflow time (450)

Elapsed time since the earthquake occurrence (s)B. Abukuma River R0.15kp

Disaster level III
Initial overflow period (340)

Ground level
behind the leveeRiverside water
level
Water level
behind the levee

E. Abukuma River L0.15kp
Levee height

Disaster level I
Initial overflow period (0)Overflow time (355)

Levee height

Ground level
behind the leveeRiverside water
level
Water level
behind the levee

Altitude Ｔ.Ｐ. (m)Altitude Ｔ.Ｐ. (m)Ground level
behind the leveeRiverside water
level
Water level
behind the levee

Ground level
behind the leveeRiverside water
level
Water level
behind the levee

Elapsed time since the earthquake occurrence (s)Overflow time (480) C. Abukuma River R0.9kp

Initial overflow period (115)

Levee height

Initial overflow period (400)Overflow time (425)

Levee height

Elapsed time since the earthquake occurrence (s)Disaster level I

Disaster level II

Elapsed time since the earthquake occurrence (s)Altitude Ｔ.Ｐ. (m)Altitude Ｔ.Ｐ. (m)Overflow time (430)

D. Abukuma River L1.3kp

F. Abukuma River L0.9kp

Disaster level I
Initial overflow period (0)Levee height

Ground level
behind the leveeRiverside water
level
Water level
behind the levee

Elapsed time since the earthquake occurrence (s)Elapsed time since the earthquake occurrence (s)Figure 3.3.3.3 Chronological change in the water level of the river side and inside the levee at the toe of levee
slope
When compared between the left and right sides ofcompared in all profiles of inundation zones andthe levee in overflow zones, the maximum water

overflow zones, which show that the initial overflow

depth at the locations B, C, and D on the right side ofperiod is identified as a critical factor that determines

the bank is much higher than that at the location F on

the magnitude of damage to levees.

the left side of the bank; however, the overflow period

For the assessment of the magnitude of damage,is around 6 to 8 minutes with little difference between

the magnitude of damage to levees should be

the left and right sides. Comparison of the initial

represented using more objective indicators, instead

overflow period shows the difference in locations withof roughly grouped zones obtained from the field

the location F zero and the locations B, C, and D fromsurvey. A cross-sectional view of the levee including

2 to 7 minutes. The results of four profiles of thesethe foundation inside the levee, divided by an equal

overflow zones show that the longer the initial

distance of 10 meters, was created, and the eroded

overflow period is or the deeper the overflow waterarea of the back slope and the foundation inside thedepth during this period is, the larger the magnitude oflevee is considered as lost area. The lost area isthe disaster. The difference in the damage level by

divided by the standard sectional area of back slope

each zone observed on the right bank can beshown around the center of the Figure 3.3.3.4 to

explained by the inundation inside the levee as seen

obtain the loss ratio. The calculation of the loss ratio ofin the three profiles at the locations B, C and D.

the levee used aerial survey data and periodical

The results on the six profiles obtained above were

profile survey data before and after the earthquake, in
148which horizontal and vertical displacements of theareas with relatively the same overflow conditions isground due to the earthquake were corrected. Before

the inundation situations in the protected land, and if

the volume of loss of the levee is used as a substitutethe period of overflow without inundation is longer, thefor the survey result, the relations between the two

profile has larger erosion damage.

were compared (see Figure 3.3.3.4). Most of the area
6.0
Average overflow water depth (m)in damage level I has a loss ratio of 0-2% and all thearea in damage level VI has a loss ratio of 100% ormore. Areas in damage level II and III are dispersedwith different loss ratios, many areas in damage level
II are found in lower loss ratios and many areas indamage level III are found in higher loss ratios,
showing that the loss ratio corresponds to themagnitude of damage. From this, it is fair to use loss

5.0

Loss ratio: 0-2%

Loss ratio: 2-5%

Loss ratio: 5-25%

Loss ratio: 25-50%

Loss ratio: 50-75%

Loss ratio: 75-100%

Loss ratio: 100%-

4.0
3.0
2.0
1.0
0.0

0

ratio as a substitute for the damage level.

100

200
300
400
Overflow time (s)

500

600

and loss ratio of leveeStandard sectional
area of back slope

Disaster level I
Disaster level II
Disaster level III

6.0

Disaster level IV

Loss ratio

Initial average overflow water depth (m)Occurrence frequency per
disaster level

Figure 3.3.3.5 Relations between overflow situations

100% or
more

Figure 3.3.3.4 Relations between loss ratio of dikeand damage level

5.0

4.0
3.0
2.0

1.0
0.0

0

Figure 3.3.3.5 shows the overflow period assigned

100

200
300
400
Initial overflow time (s)

500

600

to the horizontal axis and the average overflow water

Figure 3.3.3.6 Relations between overflow situations

depth to the vertical axis and the shape of the plot isand loss ratio of levee (with consideration tochanged by each loss ratio, plotted in accordance withinundation in the protected land)

the conditions of overflow. Also, the plots are shown in
different colors. Here, the average overflow water(2)

Research

depth refers to the average value of water depth ofCountermeasures

Committee

on

River

Tsunamioverflow that occurred during the overflow period. As it

Based on the basic principle, “disaster prevention ofgoes to the upper right corner, the conditions ofriver tsunamis is required to be implemented together

overflow are thought to become severe and the loss

with the protection at the sea shore and also plays anratio is believed to become larger; however, theimportantboundary of plots by loss ratio is vague. Figure 3.3.3.6

building,” this Committee (Chairperson: Shoji Fukuoka,

is the result obtained by assigning the average value

Professorof water depth of overflow during the initial overflow

recommendations for handling the external force of

period to the vertical axis of Figure 3.3.3.5 and thetsunamis in river management, the concept of levee

initial overflow period to the horizontal axis. Except forheight in designing facilities and methods of promotionsome parts surrounded by dotted red lines, theof tsunami-resilient community-building to contributeboundary of loss ratio is now clear.

to early recovery/reconstruction measures in disaster-

role

in

tsunami-resilientof Chuo University)community-

providesurgentFrom the result above, it is assumed that the reason

stricken rivers and to smooth implementation of the

why the magnitude of damage was different in thenational-level countermeasures against river tsunamis
149

(August 2012).

sectors, study on evacuation plans for areas

A summary of recommendations is listed below.

vulnerable to inundation by tsunamis, approaches●Basic principles of countermeasures against riverto disaster prevention education, creation of hazard

tsunamis

maps and enhancement of flood control

・Protective measures for river tsunamis should be
discussed periodically as in the case of floods.

(3) Urgent Study Committee on Earthquake-proof

・ The tsunami specified in various parameters of

Measures for River Levees

facilities in tsunami river management should be

Under the recognition that damage to river levees

treated as “tsunami related to facility design.” “Thedue to the March 2011 Earthquake reminds us of the

maximum scale of tsunami” should be treated as aimportance of ensuring anti-seismic features andphenomenon exceeding the capacity of the facility.

provides us an important opportunity to review the

They should be treated included in the disasteranti-seismic measures, this Committee (Chairperson:

reduction plans in conjunction with tsunami-resilient

Ikuo Towhata, Professor of University of Tokyo)

community-building.

gatheredknowledge

disastersfrom●Countermeasuresagainstriver

tsunamis

for

and

the

intelligent

concerning

Earthquake,discussed“tsunami facility design”

improvements of the anti-seismic measures and・By designating the geographic area defined by themethods, and released a report on specific items andmaximum distance the tsunami could travel fromissues to be addressed as anti-seismic measures forthe river mouth for facility design as the “tsunami

river levees although there still remain many issues toreach zone,” the designed high tsunami level should

be addressed in the future.

be decided as the water level to specify the height

NILIM took part in the creation of documents andof river levees for tsunami protection.

formulation of the report as a member of the・ The height of river levees as the tsunami

Committee.

countermeasure should be determined by adding

A summary of the final report is as follows.

the height necessary for the designed high tsunami●Characteristics of damage to levees

level.

・Many cases of liquefaction of foundation caused the●Response to “the largest-class tsunami”

damage to levees, in addition to many liquefaction

・River managers, as participants to develop tsunami-

cases of levee bodies, which had previously notresilient towns, should consider software andbeen taken seriously.
●Analysis of damaging process

hardware measures in a comprehensive manner.
●For

promotionof・ The damage to levees is thought to take thetsunami-resilient community-

building and improvement of river management

following three processes: (1) if a levee is built on

・ Promotion of technical development/study andsoft clay soil, the surface of the soft ground layer at

research concerning countermeasures against riverthe lower part of the levee body will sink in due totsunamis,

such

to

consolidation settlement, during which process, theunderstandandphenomenon

associated

as

study

respondandresearchtothehydrauliclower part of the levee body gets loose, (2) if the

with

river

tsunamis,levee body built on a depressed area in the ground

improvements of precision of analysis of simulation

is made of sandy soil, penetrated water, such asmodels to estimate the numerical values for riverrainfall, will be retained, forming a saturated areatsunamis and inundation, data collection and study

within the levee body, and (3) this area getson hydraulic phenomenon around the river basinliquefied due to seismic motion, reducing theand changes in the river bed along the river channel

resilience/strength and causing the levee to slidecaused by tsunamis

and crack/collapse of the crest.
●Study on the methods of verification of seismic

・Promotion of tsunami-resilient community-building,such as enhancement of coordination with urban

performance150

・ In addition to liquefaction of the foundation,

countermeasure construction, it is also important tosettlement and deformation of the levee body due toprepare contingency plans, based on the disasterliquefaction needs to be included as a verification

response simulation, etc.
・It may not be possible to protect from a large-scale

target.
・The conventional verification method seems to beor complex disaster by facilities alone, and it isrelevant for practical use for the verification onnecessary to explore responses to disaster whichliquefaction of the foundation and there is no

may hinder response by facilities, by, for example,

immediate need to change the method.

simulating an earthquake disaster occurring at the・As for verification of liquefaction of the levee body, itsame time as flooding.

is now necessary to examine the materials used forthe levee body, the water level in the levee body,(4)

the magnitude of settlement of the levee body due

Reinforcement Technology for River-mouth Weir andto consolidation settlement and the presence ofFloodgate based on the Lessons Learned from thesettlement/deformation

Great East Japan Earthquake

examined

from

the

Research

CommitteeonAnti-seismic

conditions of the foundation.

This Committee (Chairperson: Tadashi Yamada,●Study on anti-seismic engineering

Professor of Chuo University) was established for the・As a measure against liquefaction of the foundation,

design and operation of weirs and floodgates capable

it is necessary to establish a specific design methodof withstanding large-scale earthquakes and tsunamis,

to withstand level 2 seismic motions, using the anti-

based on the results of study and analysis on weirs

seismic method with experience in construction, as

and floodgates damaged by the 3.11 Earthquake anda currently available method.

Tsunami. The Committee then released a report

・ The following are possible measures against(September 2011) that put together items to beliquefaction of the levee body: “measures to reduce

addressed promptly, items necessary to be studied,

the water level within the levee body,” “measures toand R&D in the future since technology has yet to be

increase the strength of the levee body,” andestablished. As flood season was approaching, the“measures to restrain the deformation of the leveeCommittee also released urgent recommendations onbody,items to be considered concerning damaged river-while

tolerating

theoccurrenceofliquefaction.”

mouth weirs and floodgates (May 2011).

・As a measure to reduce the water level within the

NILIM took part in the creation of documents andlevee body, the drain method would be the main

formulation of the report as a member of themethod for a while. It is expected that the drain

Committee.

method has the effect to mitigate settlement and●Concept

deformation.

weir/floodgateoffuturedesignandstructureof・In the case where the drain method cannot be used,

・Learning from the experience of March 2011, it is

it is necessary to consider mitigating settlement andnecessary to clarify the specifications of river-mouth

deformation of the levee body through “theweirs and floodgates against the predicted tsunami

measures to mitigate the deformation of the leveein facility design and review the method of facility

body while tolerating the occurrence of liquefaction,”design.
・Even when the largest tsunami strikes, facilities

such as top weight, etc.
●Promotion of anti-seismic measures

should be structured to allow effective contingency

・Since verification and measures have made little

management; for example, making the river-mouth

progress thus far, it is necessary to implement

weirs be in a prescribed state by opening andverification tests as soon as possible and takeclosing the gate and making the floodgates be ablemeasures based on the results.

to shut the gates.

・ Because it takes some time to complete the・Design and structure for the predicted tsunami in151

facility design aim to minimize damage in protected

conducted studies on the effect of the 3.11

land and need to be considered in a consolidated

Earthquake and Tsunami, the shape (geographic

manner together with the operation.

feature) of levees (including foundation), soil layer

・ At facilities responsible for river runup tsunami

composition, soil property and conditions of structures,operations, it is necessary to install facilities forsuch as seawalls, as well as on the state of damage,remote control, automation, and non-power devices

such as collapse, deformation and erosion of levees.

in order to secure the safety of operators and

The Committee then released a report on theprompt and accurate operations.

mechanism of damage to levees by the tsunami●Concept for future river-mouth weirs/floodgatesbased on the identified state of damage and the basic

・A floodgate having a function as a levee shall inpolicies for the reconstruction of levees in line with theprinciple be closed at the time of a river tsunami.

mechanism of damage by tsunamis (December 2011).

・Since a weir is a multi-purpose facility, in order to

As part of support for promoting prompt and accurate

prevent occasional damage to drinking water

disaster recovery work, the Committee laid out policy

supplies due to mixture with salty water upstream ofproposals of reconstruction methods and presented a

the weir, no operation shall, in principle, be carried

mid-term

out, without leaving normal mode, in cases wheremanagement

the scale of the tsunami is expected to be small.

completion of the reconstruction work at the damage

When a large-scale tsunami is predicted, the weirzones and sites (May 2011).

reportandonpolicies

river

for

river

management

levee

until

the

shall be fully opened on an as-needed basis.

NILIM took part in the creation of documents andHowever, with respect to individual facilities, anformulation of the report as a member of theassessment and decision shall be made in a

Committee.

comprehensive●Basic policies for reconstruction

mannerbased

onpredicted

・As the main cause of damage to levees due to thescenarios.
・It is necessary to consider the case not only of the

3.11 Earthquake is liquefaction occurring in either or

estimated scale of tsunami, but also of anboth of “sealed saturated zones” or/and “foundation

unexpectedly

soils,” prevention of the recurrence of disaster shalllarge-scaletsunami(beyondexpectations) or of no tsunami despite warnings

be(inaccurate prediction).

deformation of levees due to liquefaction.

・ It isnecessary toconsiderpromoted,highlighting

thereductionof・Reducing the occurrence of liquefaction (removal ofcomprehensive

operations, such as operation characteristics andmain cause of disaster)

the normal state of the gate, the estimated scale ofRemoval of the main cause is either to reduce thetsunami, the type of warnings to be issued (tsunami

level of underground water in the liquefaction layer,

warning, tsunami alarm, large-scale tsunami alarm)

which is the main cause of liquefaction, or toand estimated time of arrival, which are thenincrease the density of or solidify the loose sandy

specified in the operation manual as far as insoil layer.
・At the locations where damage was caused mainly

advance as possible.
・In cases where machine operation is inappropriate,by the liquefaction in sealed saturated zones, aremote operation shall in principle be used in ordermethod shall be selected that would achieve either

to ensure the safety of operators, and this shall beof the above conditions, or a combination of both,

specified in the operation manual.

depending on the conditions of the site (constraintsof construction and reliability of drainage of(5)

Research

Committee

on

Reconstruction

underground water in the protected land, etc.) In theTechnology for Levees of the Kitakami River, etc.

case of reducing the water level in the protected

The Committee (Chairperson: Yasushi Sasaki,
Professor

emeritusofHiroshimaland, it is effective to install a drain device at the toe

University),of the back slope.
152

・At the locations where damage was caused mainly

for the flood season and released a report (September

by the liquefaction of foundation soils, reduction of2011), in order to carry out accurate response in thethe level of underground water is not realistic.

flood season and smooth implementation of future

Priority shall be given either to increasing theanti-seismic measures.

density of or solidifying the loose sandy soil layer.

NILIM took part in the creation of documents and・ The following are the possible processes offormulation of the report as a member of thedamage to levees caused by tsunamis depending

Committee.

on the conditions of individual rivers.

●Reconstruction work

・It is assumed that no large-scale damage, such as

・Basic policies for reconstruction at the locations

levee failure, was caused by the Earthquake in thesuffering from a large-scale disaster are totsunami-damaged zones. However, one cannot

implement liquefaction counter-measures, with an

deny the possibility of the weakening of foundation

aim to “restrict the damage to a mid-scale or lower

soils and levees due to liquefaction, affecting theeven being hit by the same level of earthquake as
3.11.”

magnitude of damage by the subsequent tsunami.
・The damage to the levees at the back slope of“embankment”

or“non-soil

embankment”

・liquefaction counter-measures for levee bodies shallisin principle be the drain method. Besides the drain

assumed to have happened in the following

method, application of the soil stabilization method

process: (1) the back slope and near the toe of theshall be discussed, with consideration to theslope (the back slope near the toe or the surface oflocation and scope of the liquefaction layer,

the foundation adjacent to the toe of slope) were

underground water (water level in the protectedscoured by the overflown stream (the direction ofland) in the liquefaction layer and economic

crossing the embankment) or by the stream alongfeasibility, etc.
・The steel sheet piling method is basically used as

the toe of the embankment slope, (2) the soil on theslope could no longer withstand the pressure,countermeasures

for

both

liquefactionof

causing a local slope failure, (3) then progressive

foundations

combinedliquefactionofslope failure occurred with further scouring, and (4)levees/foundations, but the soil stabilization method

finally, the soil section was washed away.

may be applied with consideration to the soil quality

・Possible tsunami counter-measures include surface

andof the foundation, the presence or absence of

coating (seawalls, etc.) and ensuring of a levee

cutbacks and economic feasibility, etc.
・ The

profile that can maintain some profile shape evenliquefaction

counter-measure

in

the

eroded and scoured; however, it is difficult tosurrounding area of structures shall be selected

expand the profile in a large scale because it may

comparing the steel sheet piling method and the soil

affect the nearby environment. Therefore, the basic

stabilization method with consideration to thepolicy of the counter-measures shall be surface

conditions

coating and securing (expansion) of a profile within

feasibility, etc.

of

the

foundation

andeconomic●Response in flood season

a possible scope.

・Invisible cracks and loose levees may occur due to(6)

Research

Committee

on

Reconstruction

an earthquake, which could cause levee failure due

Technologies for Levees in the Kanto Region
The

Committee(Chairperson:

Ikuo

to seepage; therefore, it is critical to detect

Towhata,abnormalities in the levees at an early stage byProfessor of University of Tokyo) conducted a survey

patrolling and to implement appropriate and timely

on damage to levees, studied the mechanism formeasures, including flood fighting methods.

reconstruction work, gathered knowledge on future

・ In addition to annual preparation for the flood

anti-seismic measures for river levees, discussed river

season, the following actions shall be taken: (1)management and effective flood control in preparation

early dispatch of flood fighters and reinforcement of
1531) HATTORI,

river patrol systems through review of the water

Atsushi,

FUKUSHIMA,

Masaki:level criteria, such as the water level at which flood

Damage to River Management Facilities byfighters must wait on standby, and critical flood

Tsunami, Document on Civil Engineering, Vol.53,

protection sites, (2) assessment of flood fighting

no. 8, pp.22-27, 2011
2) Report

methods and allocation of necessary materials and

of

the

Research

Committee

onequipment based on the state of levee disaster andReconstruction Technology for Levees of theprovisional measures, and (3) enforcement of

Kitakami River, etc., Research Committee on

information provision and information collection

Reconstruction Technology for Levees of thesystems for the people by putting up bulletin boards

Kitakami

on sites and through PR bulletins of the local

Development Bureau, MLIT, pp.19-30, 2011

River,

etc.,

TohokuRegional

3) Simulation Result of River Tsunami, materials forgovernments.
・Although all possible measures have been taken in

the 2nd meeting, Research Committee on Riveran unprecedented situation, necessary response

Tsunami Countermeasures

should still be taken as the occasion demands,

http://www.mlit.go.jp/river/shinngikai_blog/kasents

depending on the flood conditions and the results ofunamitaisaku/index.html, 2011.

monitoring.
●Future anti-seismic measures

Useful reference websites(Measures to be implemented at the moment)

1) Emergency Recommendations concerning River

・For the reconstruction in the post-flood season, it isnecessary

to

make

promptandTsunami Countermeasures, Research Committee

properon River Tsunami Countermeasures

implementation of appropriate methods, based on

http://www.mlit.go.jp/report/press/mizukokudo03_

the analysis of the disaster mechanism conducted

hh_000376.html

by the Committee.

2) Urgent Study Committee on Earthquake-proof

・In the zones where the seismicity of levees has not

Measures of River Levees

been tested, such tests should be conducted as

http://www.jice.or.jp/sonota/t1/201110240.html

soon as possible and appropriate anti-seismic

3) ResearchCommitteeonAnti-seismic

measures based on the Commission’s discussions

Reinforcement Technology for River-mouth Weirshould be implemented in necessary areas.

and Floodgate based on the Lessons Learned(Issues to be addressed in the future)from the Great East Japan Earthquake

・Discussions on the plan for stockpiling materials

http://www.jice.or.jp/sonota/t1/201106150.html

and equipment in times of peace, including

4) ResearchCommittee

on

Reconstruction

development of storage sites in order to carry out

Technology for Levees of the Kitakami River, etc.

early reconstruction

http://www.thr.mlit.go.jp/Bumon/B00097/K00360/t

・ Discussions

on

the

framework

for

rapid

aiheiyouokijishinn/kenntoukai/index.htm

reconstruction, including formulation of a manual for5) ResearchCommittee

on

Reconstruction

river patrols until the completion of reconstruction

Technologies for Levees in the Kanto Regionwork

http://www.ktr.mlit.go.jp/bousai/bousai00000057.h

・Discussions on measures to mitigate the scale oftml

disaster with an assumption of the effects on thesurrounding urban areas, a disaster covering a wide
geographic area and damage before the flood
season that are based on the disaster mechanism,
etc.
References1543.3.4 Water Resources(2) Outline of investigations(1) Outline of damage
At dams managed under the River Act, special

The Ministry of Land, Infrastructure, Transport andsafety inspections were conducted by dam managers

Tourism (MLIT) and the Public Works Research

immediately after the Great East Japan Earthquake

Instituteon March 11, 2011 (hereinafter referred to as the(detailed investigations), focusing on those dams in“3.11 earthquake”), in cases where earthquake motion

the Tohoku region where damages had been reportedof 25 gal or higher was recorded at the dam

as a result of special safety inspections, such as

foundation or where earthquake motion of JMA

deformation, increased leakage, or relatively large

seismic intensity of 4 or higher was observed at thepeak acceleration values, in order to confirm the statenearest meteorological station (Table 3.3.4.1). Theof damages reported in the special safety inspection

special safety inspections include a primary inspection

results, to evaluate the safety of the dams, and toand a secondary inspection. The former is a visualstudy countermeasures as needed. Several dams,

inspection, while the latter includes more detailed

where leakage increased in association with a rise ofvisual inspection and a safety inspection based on

the reservoir water level caused by later rainfall orvarious data measured by monitoring devices.

snowmelt, were added to the dams to be investigated,areincreased

investigations

Table 3.3.4.2 and Figure 3.3.4.1 show the outline ofinspections include increased leakage, and damages
dams

field

immediately after the 3.11 earthquake.

concrete gravity dams reported by the safety
embankment

conducted

though no damage had originally been reported

As far as the dam body is concerned, damages toto(PWRI)

field investigations and locations of dams for field

leakageinvestigations, respectively.

(seepage) as well as settlement of the dam body,
cracks on dam crests and on the upstream andTable 3.3.4.2 Outline of field investigations

downstream slopes of some earthfill dams and cracks
on the waterproof facing of asphalt faced rockfill dams.

Investigator

Although these damages are not regarded as

MLIT
Water Management Office, River
Environment Division, River Bureau
National Institute for Land andInfrastructure Management (NILIM)
Water Resources Division, River
Department
Public Works Research Institute(PWRI)
Hydraulic Engineering ResearchGroup, Dam and Appurtenant
Structures Research Team
Public Works Research Institute(PWRI)
Hydraulic Engineering ResearchGroup, Dam and Appurtenant
Structures Research Team
MLIT
Water Management Office, River
Environment Division, River Bureau
National Institute for Land andInfrastructure Management (NILIM)
Water Resources Division, River
Department
Public Works Research Institute(PWRI)
Hydraulic Engineering ResearchGroup, Dam and Appurtenant
Structures Research Team

serious enough to threaten the safety of the dams, atdams where some damages and increased leakage(seepage) were found, further monitoring has been inplace and safety measures have been taken, such as
reservoir drawdown and investigations and repair
work on the damaged places.
Table 3.3.4.1 Number of dams where special safety
inspections were conducted and the summary of the results
Manager

Total

Concretedam

Embankment
dam

Combineddam

MLIT / Japan
Water
Agency

46
(11)

31
(6)

10
(3)

5
(2)

Prefectural
Governments

104
(8)

81
(6)

22
(2)

1
(0)

Water users

213
(27)

107
(7)

101
(19)

5
(1)

363
219
133
11
(46)
(19)
(24)
(3)
* The figures in parentheses represent the number of dams wh
ere damages were reported, such as damage to the dam bodyand increased leakage.
Total

Investigationdate

Investigation site

April 7 (Thurs) –10 (Sun)Surikamigawa dam
Ishibuchi dam
Tase dam
Gosho dam
Kejonuma dam

April 23 (Sat) –24 (Sun)Kamuro dam
Takasaka dam
April 28 (Thurs)

April 28 (Thurs)

May 6 (Fri)May 22 (Sun)155

Zao damFujiigawa dam
Koyama dam
Gassan dam

1) List of results of investigations on individual dams
Table 3.3.4.3 shows the specifications of investigated

Iwate Prefecture

Gosho Damdams, major findings and outlines of the results ofTase Dam
Ishibuchi Dam

special safety inspections. Damage to the dam bodyTakasaka Dam
Kamuro Dam

Gassan Dam

and increased leakage (seepage) were observed in

Kejonuma Dam

Yamagata Prefectureeach dam, but no damages severe enough to

Miyagi Prefecture

Zao Damthreaten dam safety were found at any of these dams.

Epicenter

100Km2) Results of inspections on individual dams

Surikamigawa Dam(a) Surikamigawa dam

Fukushima Prefecture

Surikamigawa dam, shown in Figure 3.3.4.2, is an

200Km

earth core rockfill dam with a cut-off wall (with a height

Koyama Damof 105.0m) completed in 2006. The 3.11 earthquake

Fujiigawa Dam
Ibaraki Prefecturecausedanincreaseinleakage(total)from

approximately 70 L/min to 100 L/min and also caused
the following damages: settlement of the dam body

Figure 3.3.4.1 Locations of dams for field(approximately 17 cm near the maximum crossinvestigations

section) and cracks on the pavement on the dam(3) Results of investigations and discussion

crest near both abutments, primarily in the stream

Table 3.3.4.3 Specifications of inspected dams, reported damages at the time of special safety inspections andresults of detailed investigations
Year ofcompleti
on

Dam
type

Height(m)

Water level at
Distance (m)the time of theearthquake (m)Shortest
Epicentral[Reservoir water
distance
distancelevel (m)]to a fault

Surikamiga Regional
Developme
wa

2006

R

105.0

286.35［79.85］216

Ishibuchi

TohokuRegional
Developme
nt Bureau

1953

CFRD

53.0

302.37［32.37］

Tase

TohokuRegional
Developme
nt Bureau

1954

G

81.5

Gosho

TohokuRegional
Developme
nt Bureau

1981

G+R

Gassan***TohokuRegional
Developme
nt Bureau

2001

Kejonuma

Kamuro***DamManager

Volume of leakage (L/min)At the time ofinvestigation(date ofinvestigation)

Crest

138

110

474

Cracks on
the dam
crest

204

145

(184)

607

Cracks on
the damcrest

197.34［58.84］

192

121

-

-

Increasedleakage52.5

176.99［52.99］

237

157

39

125

Increasedleakage

G

123.0

222
［75］

265

204

11

14

-

6.2

32.8

Miyagi1995
Prefecture

E

24.0

25.97
［15.77］

176

121

269

495

Increasedleakage22

436

Yamagata
1993
Prefecture

G

60.6

375.9
［42.9］

231

174

18

52

-

Approx. 10

Approx. 40

Yamagata
1967
Prefecture

G

57.0

184.27［44.27］

254

197

26

32

-

Approx. 35

Approx. 15

66.0

583.17［45.17］

212

146

91

535

-

8.6

38.9

289

92

174

636

-

9*

76*

32
［5/6］

244

81

334

1242

-

83.3

137.6

152.2
［5/6］

nt Bureau***

Reporteddamages at
the time of
special safety
inspections

Foundation

TohokuTakasaka

Seismic motion**
(gal)

Zao

Yamagata
1970
Prefecture

FujiigawaIbaraki
1976
Prefecture

G

37.5

44.96
［26.96］

KoyamaIbaraki
2005
Prefecture

G

65.0

291.86［36.86］

HG

Prior to theearthquake

After theearthquake

Summary of the results of detailed investigations (concerning major
damages, etc.)･ Settlement of dam body (maximum 17cm)･ Cracks on the pavement of the dam crest near both abutments(later found to be minor, remaining within the protective layer, by the［4/7］
follow-up investigation)･ Increased leakage (found to be caused by snowmelt)
River bed:
River bed:
River bed:･ Settlement of dam body (maximum 1cm)
Approx.
Approx.
Approx. 2000 ･ Cracks at the foundation of the crest parapet
2000
3000*
Right bank･
Increase in leakage measured at the foundation (found to be
Right bank Right banktunnel: Approx.
tunnel:tunnel:caused by afflux of the water level due to adhering of algae)
Approx. 440 Approx. 700
710･ Exfoliation of parapet concrete on the crest and opening of cracks
and level differences on crest pavement joints
Approx. 40
1469･ Increased leakage (less than 10L/min each) from the scupper on［4/8］
the joint (near the maximum cross section) and muddy water(disappeared the day after)
Concrete Concrete Concrete dam/ ･ Increased leakage from the scupper on the joint (J4) at the concrete
dam
sectionapprox. 60
dam/
dam/
･ Settlement (very little) of the embankment body
［4/9］
approx. 20 approx. 70
Approx. 70 Approx. 100

Approx. 85

189［5/22］

Approx. 40［4/10］

Approx. 230［4/24］
Approx. 300［4/24］
Approx. 50･ Leakage from the scupper on the joint (J14) (approx.25L/min, later
stabilized)･
Increased leakage from the scupper on the joint (J18, J17, etc.)
at the time of water level increased since the end of April･ Increased uplift pressure at the foundation scupper (BL18)･ Settlement of dam body (maximum of 14cm)･ Cracks at the joints around the left and right banks of the dam crest･ Rapid increase in leakage (right bank) immediately after theearthquake (subsided later)･ Increased leakage from the scupper on the joint (2J3) along with therise in the reservoir water level at the beginning of April(implemented detailed investigation and countermeasures later.
Tends to be stabilized)･ Increased leakage from the scuppers on the joints (J9, J10) alongwith the rise in the reservoir water level at the beginning of April(implemented detailed investigation and countermeasures later.
Tends to be stabilized)･ Increased leakage from the foundation scupper (7BL, etc.)［4/28］･ Increased leakage from the foundation scuppers at the maximum
cross section (BL 4,5)･ Leakage from the scupper on the joint (J4)
* Leakage before and after the earthquake is given for reference(automatically measured value, which is later found to be larger than
the actual value when compared with manually measured value)･ Increased leakage from the scuppers on the joints (J5, J19, etc.)(silty sediments around the scuppers)･ Leakage around the foundation scupper (BL21)* G: Concrete gravity dam, HG: Hollow gravity concrete dam, R: Rockfill (earth core), CFRD: Concrete faced rockfill dam, E: Earthfill dam** Peak value of the horizontal component (stream direction and dam axis direction). Value of Ishibushi dam (foundation) is for reference (recorded at the right terrace, not bedrock). Maximum
value of Tase dam is unknown.
***No specific deformation was reported by the special safety inspections immediately after the earthquake, but detailed investigations were conducted because increased leakage was later
observed as the reservoir water level rose.

156

direction (Photo 3.3.4.1, Photo 3.3.4.2).

continued measuring the depth of the cracks andAs a result of the investigation, it was concluded

monitoring the data on leakage to take every possiblethat the safety of the dam was intact due to themeans to ensure safety. As a result of the follow-up

following findings: the earthquake-induced leakage

investigations by the manager, the depth of the cracks

increase and settlement were small relative to thewas found to be shallow, staying within the protective

scale of the dam, the values of these changes werelayer of the dam crest.

stabilized, the cracks in the crest pavement were
narrow, and no change was found in the upstream(b) Ishibuchi dam

and downstream surfaces. Still, the manager has

Ishibuchi dam (Figure 3.3.4.3) is a concrete faced(a) Plan(b) Cross section
Figure 3.3.4.2 Surikamigawa dam

Photo: 3.3.4.1 A crack at the attaching portion of the

Photo 3.3.4.2 Close-up of a crack that appeared onleft bank of the dam crest (Surikamigawa dam)the dam crest pavement (Surikamigawa dam)157

rockfill dam (CFRD) with a cut-off wall (CFRD) (with aof the dam, the pavement was buckled and cracked

height of 53 m) completed in 1953. When the Iwate-

and gaps appeared on the boundary between the

Miyagi Inland Earthquake of 2008 (M7.2, inland active

parapet and pavement (Photo 3.3.4.3). The 3.11

fault earthquake) hit the dam, a seismometer installed

earthquake left much smaller damage than that by theat the dam crest recorded a maximum acceleration of2008 earthquake, despite some settlement of the dam

1,461 gal (stream direction) and 2,070 gal (verticalbody and widening of gaps at the foundation of a crest

direction). The dam was reported to have incurred theparapet due to structures buried in the dam body (thefollowing damages due to the earthquake; at the crest

piers of the tramway left buried in the dam body at the(a) Plan(b) Cross section

Figure 3.3.4.3 Ishibuchi dam

Photo 3.3.4.3 Crest of the Ishibuchi dam (earthquake

Photo 3.3.4.4 Crest of the Ishibuchi dam (3.11

of 2008)

earthquake)* a trace of pavement repaired was caused by earthquake of 2008

158

time of construction) (Photo 3.3.4.4). Since a rather

on April 7. From these data, it was found that there

large settlement occurred at the Ishibuchi damwere no problems threatening the safety of the dam,

(approximately 55 cm near the maximum cross-because the earthquake-induced settlement was

section) due to the 2008 earthquake, continuous

small and no damage was found on the cut-off wall

observation of displacement has been conductedsurface at the upstream. An increase in the measured

using GPS sensors at the dam crest and various sites

leakage (from approximately 2,000 L/min to aboutof the upstream and downstream slopes in order to

3,000 L/min) reported from the special safety

monitor the movement of the dam body (Figure

inspection was found to be caused by the blocking of

3.3.4.4), and data were also obtained when the 3.11

the water level inside the channel due to adhering

earthquake occurred. Among such data, Figure

algae. Nonetheless, in order to take every possible

3.3.4.5 shows the result of the observation point G-9

measures to ensure safety, the manager hasof the dam crest at the maximum cross section. From

continued monitoring the data on leakage at this point

the Figure, it is clear that the maximum differential

and other points, and others and others.

settlement of about 12mm was caused by the 3.11
earthquake and a smaller scale of settlement occurredat the time of an aftershock (at a maximum of M7.1)

Diversion tunnel

K -1 Reference point

Effluent
outlet

G-15

G-1

G-14

G-10

G-9

G-5

G-4

Power regulating tower

Survey Line No.15

G-13

G-12

G-11

G-8

G-77

G-6

G-3

G-2

G-1

Survey Line No.25

Survey Line No.20

GPS
monitoring
point
：GPS
計測点

Survey Line No.30 Survey Line No.35

Plumbing tower

Temporary diversion
tunnel

G-16(No.20 Crest)

Measured data

Trend line

Final data: at 00:00 on April 15, 2011(a) Downstream and upstream directions
Upstream

Left and Right bankdirections (mm)Downstream(a) Left and Right bank directions

Vertical direction (mm)Downstream and upstream
directions (mm)Figure 3.3.4.4 Displacement observation at the Ishibuchi dam (layout of GPS sensors)(a) Vertical direction

Left bank
Right bank

About 12mm

UpliftSettlement

The 3.11 Earthquake 14:46

4/7 23:32 Maximum aftershock* Displacement sets zero at the time when GPSs were placed just after the Iwate-Miyagi Inland Earthquake in 2008.

Figure 3.3.4.5 Changes in displacement of Ishibuchi dam body observed by the GPS

159

(c) Tase dam

problems threatening the safety of the dam from theTase dam (Figure 3.3.4.6) is a concrete gravity dam

fact that these damages were minor and leakage from(with a height of 81.5 m) completed in 1954. The 3.11

each transverse joint was low at no more than about

earthquake increased the total leakage from 14 L/min

10 L/min. However, since leakage from scuppers on

to 69 L/min (Figure 3.3.4.7), and caused exfoliation of

the joint was observed, which had been nearly 0 L/min

parapet concrete at the crest and opening of cracks

before the earthquake, the manager has continued

and level differences on the crest pavement (Photo

monitoring the leakage with consideration to the

3.3.4.5, Photo 3.3.4.6). As a result of the detailed

relations with the reservoir water level in order to takeinvestigation, it was concluded that there were no

every possible measure to ensure safety.

(a) Longitudinal section(b) Cross section

Figure 3.3.4.6 Tase dam

Photo 3.3.4.5 Exfoliation of parapet concrete (TasePhoto 3.3.4.6 Level difference at joint of crest

dam)

pavement (Tase dam)160

Leakage (ℓ/min)

120
100

Leakage
Reservoir
water level

210
200
190

↓

185
180

60

175
40

170

was also observed for the first time from the gallery on
the downstream slope. Thus, the manager has
continued monitoring, focusing on said locations (as ofAugust 2012, leakage has been stabilized).

165

20
3/31

3/29

3/27

3/25

3/21

3/23

3/19

3/17

3/15

3/13

3/9

3/11

3/7

3/5

3/3

160
3/1

0

leakage increased from 20L/min to 35L/min. Leakage

205
195

The 3.11 Earthquake

80

maximum of 20L/min. After the 3.11 earthquake, the215

Reservoir water level (m)Increase of the leakage with elevation ofground water surface due↓ to snow melting

140

155

上
流
側

Figure 3.3.4.7 Leakage at Tase dam

下流側(d) Gosho dam
Gosho dam (Figure 3.3.4.8) is a combined dam with

J-4 漏水量a concrete gravity dam section, including spillway, and

地震により下流側壁面
からも漏水が発生

a rockfill dam section connected of a concrete part(completed in 1981 with a height of 52.5 m). The 3.11

パイプによる導水

earthquake caused an increase in leakage fromapproximately 20L/min to 70L/min. Major leakage
occurred at the transverse joint (J-4) as shown in
Photo 3.3.4.7. Leakage from this joint had previously

Photo 3.3.4.7 Leakage at the joint of the concrete gravity dam

been observed during the winter when the concrete

section (J-4) (Gosho dam, concrete gravity dam section)

contracted due to the low temperature with theJ-4(e) Kejonuma dam(a) Plan(b) Longitudinal section

Figure 3.3.4.8 Gosho dam

161Kejonuma dam is an earthfill dam (with a height ofat different locations: namely, the left bank, center,

24.0m) completed in 1995. After the 3.11 earthquake,right bank and borehole. A large increment of leakage

the total leakage (seepage) increased rapidly fromis observed at the right bank of the dam, with the

20L/min to 430L/min. At this dam, leakage is observed

increment from 7L/min to 290L/min. The leakage(a) Plan(b) Cross section

Figure 3.3.4.9 Kejonuma dam

右
岸
側

左
岸
側

貯
水
池

Photo 3.3.4.8 Cracks appeared upstream andPhoto 3.3.4.9 Opening between curb at the crest

downstream directions (Kejonuma dam)center and pavement (Kejonuma dam)162

subsided quite rapidly after that, and it has been

(M7.4) thus far on April 7. Although any correlation

stabilized at 50L/min since March 15 (Figure 3.3.4.10).

between the reported increase in leakage and the

The 3.11 earthquake caused a settlement of 13.9cm

earthquake is unknown, detailed investigation wasand deformation of 5.8cm towards the downstream

carried out upon a request made by the Yamagata

direction near the center of the crest, where thePrefecture (local government), the manager of thesemaximum deformation was observed. At the crest ofdams, in order to examine the cause of the increase

the dam body, several cracks were extended to theand possible countermeasures. The peak acceleration

downstream and upstream directions, of which 2.5-

(horizontal component) of seismic motion observed at

3cm of cracks were observed on the left bank (Photothe foundation of these dams ranged from 15 gal to 25

3.3.4.8). There was an opening between the curb

gal, which is not particularly high. As a result of thealong the center to the left bank of the crest and theinvestigation, the main damage to the Kamuro dam

pavement (Photo 3.3.4.9). As for the investigation,

was notable leakage at the scupper of the transverse

there were no damages threatening the safety of thejoint (2J3) (Photo 3.3.2.10), which was found higher

dam, however, continuous monitoring of leakage

than the maximum value observed at the same

(seepage) is needed.

reservoir water level in the past (Figure 3.3.4.13).
However, no noticeable change was observed in the

500

leakage from the foundation scupper, nor was there30

uplift pressure at the foundation or displacement of

450
25
Total leakage
Reservoir water level

350
）

300
250

20
15

200
10

150
100

5

the dam body. As for Takasaka dam, notable leakage

Reservoir water level EL. (m)Leakage (ℓ/min)

400

from the scuppers of the transverse joints (J9) (Photo3.3.4.11) and J10 was observed (Figure 3.3.4.14). No
leakage from the foundation scupper or muddy water
was observed.

0

3/11
3/12
3/13
3/14
3/15
3/16
3/17
3/18
3/19
3/20
3/21
3/22
3/23
3/24
3/25
3/26
3/27
3/28
3/29
3/30
3/31
4/1

50

Although it was concluded that no damage was0

observed that may threaten the safety of the dams,
the manager has continued monitoring the leakage

Figure 3.3.4.10 Leakage at Kejonuma dam

and gaps focusing on the transverse joints where alarge amount of leakage was observed and conducted(f) Kamuro dam and Takasaka dam

investigations on leakage paths for countermeasures.

Kamuro dam (Figure 3.3.4.11) is a concrete gravity

Later, countermeasures were taken against thedam (with a height of 60.6m) completed in 1993, andleakage from the transverse joints at both dams using

Takasaka dam (Figure 3.3.4.12) is a concrete gravity

a leak-stop agent based on the results of thedam (with a height of 57.0m) completed in 1967.

investigation on leakage paths. Monitoring has

Approximately one month after the 3.11 earthquake,leakageincreased

remarkably

at

both

continuously been conducted. The leakage tends todams,stabilize (the leakage has stabilized as of February

corresponding to the rising reservoir water level due to2012).

snow melting and rainfall and the largest aftershock

163

2J3

(a) Longitudinal section(b) Cross section

Figure 3.3.4.11 Kamuro dam

J10J9(a) Longitudinal section(b) Cross section
Figure 3.3.4.12 Takasaka dam

164Photo 3.3.4.10 Leakage from the transverse joint

Photo 3.3.4.11 Leakage from the transverse joint(2J3) (Kamuro dam)

(J9) (Takasaka dam)

Total leakage
2J3leakage

Reservoir water level EL. (m)Leakage (ℓ/min)Reservoir water
level

Figure 3.3.4.13 Time history of leakage at Kamuro dam

165Reservoir water level EL. (m)Leakage (ℓ/min)

Total leakage
J10 Leakage
J9 Leakage
J3 Leakage
Total foundation
J2 Leakage
Reservoir water level drainage

Figure 3.3.4.14 Time history of leakage at Takasaka dam

Figure 3.3.4.15 Distribution of seismic intensity around dams and peak acceleration at dams on the Great East
Japan Earthquake(4) Observed seismic motions
166

Table 3.3.4.4 Peak horizontal acceleration at dam foundation(Records of 100gal or higher at dams managed by MLIT (under the jurisdiction of MLIT)

48
73.5
45.3
23.5

Maximum
acceleration(Foundation)
(gal)
313
293
290
290

Type

Height
(m)

G
G
G
E

46.0
48.6
65.0
19

G

45.5

125

Horikawa dam
Shiramizugawa dam
Mano dam

Pref. Yamagata
Pref. Ibaraki
Pref. Ibaraki
Pref. Miyagi
Tohoku Regional
Development
Bureau (Miyagi)
Pref. Fukushima
Pref. Yamagata
Pref. Fukushima

Maximum
acceleration(Foundation)
(gal)
144
139
334
133

Tomeyamagawa dam
Jyuo dam
Koyama Dam
Kamiosawa dam

R

43

272

Kamafusa dam

G
E
G

46
24
37

271
269
239

R
G
G

57
54.5
69

124
114
114

G

65

195

Shiobara dam

Pref. Tochigi

G

60.0

112

CFRD

53

184**

Kodama dam

Pref. Fukushima

G

102

111

G

33.7

183

Surikamigawa dam

R

105

110

G
R
R
R

47.8
83.5
43.5
74.4

110
110
105
102

Dam

Manager(Prefecture)

Type

Height(m)

Miyatoko dam
Hayachine dam
Hananuki dam
Sohnoseki dam

Pref. Miyagi
Pref. Iwate
Pref. Ibaraki
Pref. Miyagi

G
G
G
G

Tarumizu dam

Pref. Miyagi

Minamikawa dam
Kejonuma dam
Komachi dam

Pref. Miyagi
Pref. Miyagi
Pref. Fukushima
Tohoku Regional
Development
Bureau(Fukushima)Tohoku Regional
Development
Bureau (Iwate)

Miharu dam

Ishibushi dam

Mizunuma dam

Pref. Ibaraki

DamManager(Prefecture)

Tohoku Regional
Development
Bureau(Fukushima)
Pref. Miyagi
Pref. Fukushima
Pref. Miyagi
Pref. Miyagi

Nanakita dam
Pref. Miyagi
R
74
177
Hanayama dam
Tohno dai-ni dam
Pref. Iwate
G
23.1
175
Yoji dam
Fujiigawa dam
Pref. Ibaraki
G
37.5
174
Oda dam
Takashiba dam
Pref. Fukushima
G
59.5
151
Aratozawa dam
Kido dam
Pref. Fukushima
G
93.5
150
*G: Concrete gravity dam, R: Rockfill dam (earth core), CFRD: Concrete faced rockfill dam, E: Earthfill dam**Value for Ishibuchi dam at the hill of the right bank (not bedrock)1) Peak acceleration

recorded at the dam foundation and at the crest,

Figure 3.3.4.15 shows the peak acceleration

respectively. Likewise, at Surikamigawa dam, peakrecorded/reported by the seismometers installed ataccelerations of 110.3 gal and 473.9 gal were

the foundation of the dams and inspection galleries inrecorded at the dam foundation and at the crest,

the low altitude area. The number of dams under therespectively. As Figure 3.3.4.16 and Figure 3.3.4.17

jurisdiction of MLIT which registered a horizontal

indicate, the duration of the seismic motion of the 3.11

acceleration of 100gal or higher was 23 dams (fourearthquake is characteristically very long.

dams under direct control of MLIT and 19 dams under
the jurisdiction control of MLIT) (Table 3.3.4.4).
Although the magnitude of the 3.11 earthquake wasextremely large, since each dam was locatedrelatively far from the source fault of the earthquake,the peak acceleration was not particularly large
compared with records observed at dams near the
epicenter of the past inland active fault earthquakes.
3) Acceleration time history
Acceleration time history observed at the Miharu
dam (concrete gravity dam) and Surikamigawa dam(rockfill dam) are shown in Figure 3.3.4.16 and Figure
3.3.4.17,

respectively.

At

Miharudam,

peak

accelerations of 194.8 gal and 932.4 gal were167

Upstream and downstream directions

Upstream and downstream directions(Maximum acceleration: 194.8gal)(Maximum acceleration: 932.4gal)

Dam axis direction

Dam axis direction(Maximum acceleration: 130.8gal)(Maximum acceleration: 661.2gal)

Vertical direction

Vertical direction(Maximum acceleration: 146.9gal)(Maximum acceleration: 262.5gal)(a) Dam foundation(b) Dam crest

Figure 3.3.4.16 Acceleration time history observed at Miharu dam

168

Upstream and downstream directions

Upstream and downstream directions(Maximum acceleration: 81.6gal)(Maximum acceleration: 473.9gal)

Dam axis direction

Dam axis direction(Maximum acceleration: 110.3gal)(Maximum acceleration: 294.1gal)

Vertical direction

Vertical direction(Maximum acceleration: 79.8gal)(Maximum acceleration: 224.8gal)(a) Dam foundation(b) Dam crest

Figure 3.3.4.17 Acceleration time history observed at Surikamigawa dam(5) Conclusion

An extremely long duration of seismic motion can

On the Great East Japan Earthquake of Marchbe noted as a characteristic of the 3.11 earthquake. In

2011, special safety inspections were carried out at athis respect, further elaborated/detailed analysis andnumber of dams in East Japan. As a result, noevaluation

damage severe enough to threaten safety was foundcollection and analysis of records of seismic motion,at any of the dams inspected. Although further

so that findings would be reflected in the safety andinvestigation and analysis are needed to elucidate themanagement of dams and the ongoing evaluations offactors contributing to this, it appears to be because

the seismic performance of dams.

arewarranted,

together

with

more

almost all dams in Japan, except earthfill dams, areconstructed on solid bedrock, and because the source

References

fault of the earthquake was relatively far from the1) Public Works Research Institute, National Institutedams so the seismic motion was not felt as strongly

for Land and Infrastructure Management: Quickas the seismic motion observed at dams close to theReport on Damage to Infrastructures by the 2011

epicenters of the inland active fault earthquakes in theoff the Pacific coast of Tohoku Earthquake,

past.

Technical Note of National Institute for Land and169

Infrastructure Management, (no.646), Technical
Note

of

PublicWorks

Research

Institute,(no.4202), pp.342-366, 2011
2) YAMAGUCHI, Yoshikazu: Evaluation of Seismic
Behavior of Dams (Safety) at The Great East
Japan Earthquake and Characteristics of the
Observed Earthquake Ground Motions, Japan
Dam Engineering Center, lecture on Measures toStrengthen

Flood

Control

Facilities

againstEarthquake and Tsunami of the Great East Japan
Earthquake”

(at

Water

Resources

Agency,Ministry of Economic Affairs, Republic of China),
2012

170

3.3.5 Shore and Coastreconstructed,(1) Method of setting design tsunami water level

damaged dikes is the very first step of recovery for the1) Backgrounddisaster affected areas, so such a method has to be

The Committee for Technical Investigation on

becausethereconstructionofprepared quickly so as to accelerate the recovery.

Countermeasures for Earthquakes and Tsunamis
Based on the Lessons from the "2011 off the Pacific2) Official notice on setting design tsunami water level

Coast of Tohoku Earthquake" of the Central DisasterOn receiving the abovementioned report, the NILIM,

Prevention Council (hereinafter referred to as thein collaboration with the Seacoast Office, Water and

1)

Technical Investigation Committee) released a report .

Disaster Management Bureau, Ministry of Land,

The report includes the following recommendations:

Infrastructure, Transport and Tourism, surveyed andFuture tsunami countermeasures should be preparedprepared the methods for determining the applicable

based on the simulations for the following two levels ofdesigntsunamis as follows: First, for the simulations fortsunamis—and the required dike height corresponding

preparing the integrated disaster prevention measures

to such design tsunami height; the results of the

focusing on the protection of human life and residents’survey were announced as an official notice dated

properties, the worst-case maximum level of tsunami

July 8. Particularly, the NILIM, during the process of(conventionally called “the level-two tsunami”), should

identifying the target coasts and investigating the past

be applied – although its occurrence frequency is low,tsunami traces, collaborated with the Tohoku Regional

it will cause disastrous damages once it occurs.

Development Bureau. In addition, the NILIM, prior to

Second, for the simulations for designing coastal

the announcement of the abovementioned notice,protection

fromcollected comments from academic experts at the 2nd

inundating inlands, the tsunamis conventionally calledmeeting of the "Committee for Technical Investigation“the level-one tsunami” should be applied – althoughon Coastal Countermeasures for Tsunamis.”facilities

toprevent

tsunamistsunami—typicalandrelatively

frequent

2)2)

their heights are lower than the worst-case maximum

The notice specified the procedure of determining

level tsunami, they occur more frequently than thethe design tsunami water level and dike crown height

worst-case tsunamis and cause heavy damages. In

as follows:

addition, the Technical Investigation Committee

・Divide the coastline into subdivisions (sub-coasts) inrecommended that, for such purposes in addition toeach of which the tsunami force can be assumed

the protection of human life as the protection of

uniform, according to “geographical conditions such

residents’ properties, the preservation of regionalas

economic activities, and the security of production“experienced tsunami heights of the past tsunamis

sites, the coastal protection facilities should berecorded in historic documents or archival damage

designed and developed for the relatively morerecords and the tsunami heights obtained throughfrequent tsunamis. The conventional facilities havesimulations”. (Figure 3.3.5.1)

functioned effectively for the prevention of damages
that would be caused by the tsunamis with a height
less

than

a

certainvalue.

Therefore,

therecommendation is reasonable because, from theviewpoints of costs, environment, and coast utilization,
it would be unrealistic to raise the design tsunami
heights extremely to prepare for the worst-casemaximumtsunami.

In

addition,theTechnical

Investigation Committee made comments on thenecessityofpreparingthemethodsforthedetermination of the height of the dike that will be

171

bay

shapesorhillsideconnections”

and

2

0 1 2

4

governments, and the Japan Meteorological Agency.

6km

In the case where, although an earthquake

Sub-Coast A

occurrence was recorded in historical documents orarchives, no tsunami trace height measurement is

Sub-Coast B
Local
Coast 2

Local
Coast 1

Local
Coast 3N

available, estimate the height as accurately as

Coastpossible by simulations within practical limitations;note that in this case the inundated areas must be

Sub-Coast C

clearly

Local Coast 4

grasped

using

the

tsunamisediment

investigation reports.

Sub-Coast D

・ Calculate a tsunami water level distribution fortarget tsunami group through simulations under the
Figure 3.3.5.1 Example of the Subdivision of Coastline

boundary condition that the progression of tsunami

into Sub-coasts

inundation stops at the dike locations. Based on the
results of the simulations, discuss among the・Select, as a target tsunami group, a group of typicalneighboring coast administration agencies. Finally, set

tsunamis estimated to have occurred generally with athe design tsunami water levels for the tsunamis listed

certain frequency (once in several decades orin the target tsunami group. Principally, a sub-coastcenturies) which can be used for setting the design

can have only one design tsunami water level.

tsunami water level through analyzing the past

However, in the case where the design tsunami watertsunami trace heights and taking into considerationlevel can be judged significantly differently along its

the estimated tsunami water level caused by thecoastline, it is allowable to subdivide the sub-coast toconcerned possible earthquakes (Figure 3.3.5.2).

assign different design tsunami water levels to the

When viewing figure 3.3.5.2, note the following:subdivisions. Note that in such a case, reasons for

Tsunami trace heights must be represented in T. P.

dividing the sub-coast must be clearly stated.

value (height above the Tokyo Peil);
Tsunami trace investigations must be conducted20

3)

Tsunami Height above T.P.(m)according to the site investigation manual preparedby the Coastal Engineering Committee, Japan Societyof Civil Engineers or the equivalent, or using theheight measurements following the abovementioned
manual. In the case where no other measurements
are available than those obtained through otherprocedures than the measurements described above,
choose reliable measurements such as those certified

2011 off the Pacific Coast of
Tohoku Eathquake (M9.0)

Worst-Case Maximum Level of Tsunami
15
Showa Sanriku (M8.2)

4)

A Group of Design Tsunamis(Once in Several Decades or Centuries)

5

Far off the Sanriku (M7.7)

Kamchatka (M8.2)

Ansei off the Sanriku (M8.0)

Off theUrup (M8.1)

Off the Nemuro Peninsula (M7.9)

1968 off theTokachi (M7.9)

1600

1700

Tsunamis without Trace

Tohoku Earthquake Tsunami Joint Survey Group .

Simulation

Meiji Sanriku （M8.5）

10

0
1500

as site investigation measurements by the 2011

Chili Earthquake (M9.5)

1800
Year

1900

2000

2100

Figure 3.3.5.2 Example of Classification of TsunamiCollect tsunami traces as close to a coastline as

Heights Caused by the Past Earthquakes (in Sub-possible.

Coast A)In the case where a tsunami trace height is missing
which needs to be compensated for, use a・ Coastalmeasurement presented in publications such as
5)“Nihon Higai Tsunami Sou-Ranmanagers

areinchargeofthe(in Japanese)

determination of crown heights of dikes. The(comprehensive list and description of tsunamis anddetermination of a dike crown height should be indamages in Japan) or the official investigation reports

compliance with the conventional specification thatby the regional development bureaus, the local

have determined to satisfy the requirements for a dike172

to protect against tsunami or high-tide inundation or to

managers set design forces on a coast-by-coast basis.

reduce overtopping waves. A crown height must
exceed the value of the design tsunami water level or(2) Analyses of dike damages“design high-tide level plus run-up height of the design

1) Backgroundwave” or “the sufficient height for effectively reducing

In the Great East Japan Earthquake (hereinafter

the volume of water overtopped by the design wave atreferred to as the Earthquake), many coast protection

the design tidal level” considering the freeboard

facilities suffered damages. The Central Disaster

determined

Prevention Council

by

the

backlandconditions.

1)

This

, in order to cope with suchdetermination should be made through a synthetic

situations, presented the following recommendation:

judgment by taking into considerations the diversified“the government should promote the development offunctions of the coast, environmental protection,technologies that enable the construction of sucheconomic

efficiency,

surrounding

landscape,structures that, even in a situation where a tsunami

economic

efficiency,

maintenanceconvenience,higher than the design tsunami height hits, resiliently
maintainconstruction convenience, and public usage.

theirfunctions,anddevelopfacilities

adopting such technologies.” “To resiliently maintaintheir functions” in that context means to prolong as3) Difference from the conventional method
The three prefectures having quake-hit areas inlong as possible the time to destruction or collapse of

their lands—Iwate, Miyagi, and Fukushima, havedikes, to reduce as much as possible the likelihood offinished

abovementioned

full destruction in order to preserve time for evacuation,

procedure, and completed the setting of design

or to reduce the damages a second tsunami would

tsunami water levels and planned dike crown heights.

give, and to enable prompt recovery; this would help

Note that the new setting procedure of design tsunami

reduce the risk of second disasters or costs forwater level has three significant differences from therecovery . Following this recommendation, the River

conventional method as follows:

Department, NILIM, has started analyses of three-workfollowingthe6)First, earthquake occurrence frequency is clearlysurface armored coastal dikes (hereinafter referred totaken into consideration in the new method. While theas coastal dikes) among the coastal protection

conventional method uses, as a design quake, thefacilities located in the prefectures from Aomori tomaximum quake in the past or well-known quakes,

Chiba, focusing on their damage situations and thethe new method adopts the additional process ofrelations between their structural characteristics andchoosing the target tsunami group explicitly adopting

tsunami forces. The data used for analysis was

the quake occurrence frequency—for example, oncecollected by the Seacoast Office, Water and Disasterin several decades to several centuries.

Management Bureau, Ministry of Land, Infrastructure,

Second, while, in some cases with the conventional

Transport and Tourism and the Coast Division, NILIM,

method, tsunami trace heights were used for design

with the cooperation of the concerned government

tsunami water levels, the new method sets design

ministries and the disaster-affected prefectures for thetsunami water levels based on the results of

purpose of discussions at the “Committee forsimulations

Technical Investigation on Coastal Countermeasureswhere

consideration—thedikes
progress

are

taken

in

into

for Tsunamis.”simulation

technologies has enabled such techniques. This

Coastal dikes, generally except for the cases wheremeans that the new method explicitly takes into

sufficient construction spaces are unavailable, have aconsideration water rises caused by dikes.

three-surface armored structure consisting of a body

Third, the concept of sub-coasts is adopted; thismade of piled-up soil, a concrete-armored seaward

enables setting design forces according to theslope, a concrete-armored crown, and a concrete-

geographicalarmored landward slope (Refer to Figure 3.3.5.3). The

conditions,incontrast

with

the

site

conventional method where, in some cases, coastal

173

investigations

conducted

shortly

after

the

Earthquake found many cases where the landward

reason that the preliminary surveys on the complete

slope toe was scoured (Photo 3.3.5.1); this suggests

collapse of 156 sites in total showed the following: thethat the loss of base due to scouring led to themedian value of the collapse lengths was 44.6 meters;

washout of landward slope armoring soil, the washout

73.7 percent of the collapse lengths were less thanof body soil, and the final collapse of coastal dikes

100 meters.

(Figure 3.3.5.4).

The grade of collapse—complete or partial—of theinvestigated facilities was judged as follows:
Crown Width

Seaward Slope
Gradient

In the case where the dike armoring and base soil
were completely lost, the dike was judged to be in a

Relative
Elevationstate of “complete collapse:”
In the case (as shown in photo 3.5.5.2) where theLandward
Slope Gradientarmoring soil was partially lost, or a part of the base

Landward Slope Toe Armoringsoil remained even though the dike armoring was

Figure 3.3.5.3 Basic Structure of Three-Surface

completely lost, the dike was judged to be in a state ofArmored Coastal dike“partial collapse.”
The “overtopping water depth” was obtained by

2) Analysis procedure of dike damages

subtracting dike crown height after ground subsidencea) Collection of damage cases and their damage

related to the Earthquake from the tsunami inundation

evaluation

height recorded in the preliminary report dated August
4)

26, 2011, prepared by the 2011 Tohoku Earthquake

In terms of the identification of damaged portions,

Tsunami Joint Survey Group.

coastal protection facilities need to be divided into
subdivisions (shown in Figure 3.3.5.5 as “sections”)
so that each section has a single uniform structure,
because, even if a facility is administered as a single
administration unit, it would consist of different
structures in some cases. During the investigation,
facility structural parameters such as crown heights
and slope gradients were obtained from facility data
book, complete collapse length, number of complete
collapses, number of units of complete collapse,

Photo 3.3.5.1 Partially Collapsed Three-Surface

partial collapse length, and overtopping water depth.
These parameters

Armored Coastal Dike and Scouring Situation at thewere obtained by following

Landward Slope Toe (Kabasaki Coast, Iwanuma City,

manners.

Miyagi Prefecture)

The “number of units of complete collapse” iscounted as follows: divide again a section of a facilityof a uniform structure into small 100 m-units; then,Wave Forcecount the number of units that suffered complete

Scouring at the
Landward Slope Toecollapse;
The number of units of complete collapse was
Washout of Landward
Slope Armoring

adopted as a supplemental index representing theseverity of damage caused by a leading wave, for the

Washout ofCrown Covering

reason that the complete collapse length canoverestimate

theseverity

in

the

case

where

Washout of
Body Soilbackwashes caused additional damages;

Figure 3.3.5.4 Collapsing Process starting at

The unit length of 100 m was adopted for the174Landward Slope Toe

backland ground, and crown width, the differencesamong the damage states were analyzed as follows:b) Measurement of complete collapse length using•Two-group comparisonssatellite or aerial photos

With regard to each characteristic element, thePrecise damage data were obtained by analyzing

statistical relation of the overtopping water depth andthe aerial photos taken shortly after the Earthquake by

the calculated collapse length ratio (the ratio of

the Geospatial Information Authority of Japan andcollapse length to the total facility length) was

Google Earth satellite images taken in April 2011. The

analyzed between the two groups, each of which hasreports and measurements by the coastal manager

an almost equivalent number of members. Note thatlocatedwere

the data samples were arranged according to Table

reinvestigated. And armoring width, complete or

3.3.5.1 so that the non-target characteristics havepartial collapse length, the number of collapsed units

almost an equivalent number of members, except forand their grade (complete or partial) were measured

the crown width which had an insufficient value

in the case where the landward toe of the structure

distribution to be divided into two groups. Two-group

was covered. The partially and complete collapse

comparisons were not applied to crown width, but only

lengths were re-measured by the authors in a unified

the multivariable analysis, described later, was applied.

in

each

affected

prefecture

way because the coastal managers used different
criteria for the states of collapse (complete or partial).

Local
Coast A

Table 3.3.5.1 Group-Division Criteria
TargetCharacteristics

Local Coast B
Section１

Complete
StructureＡ Collapse
LengthLocal Coast C

Landward
Slope Toe
Armoring
Seaward Slope
Gradient
Landward
Slope Gradient
Relative
Elevation

Section２

Dike
LengthLandward
Slope Toe
Armoring

Non-target Characteristics
SeawardLandward
Relative
Slope
Slope
Elevation
Gradient
Gradient

N. A.

Less than
50 %Less than
50 %More than
3m

None

N. A.

Less than
50 %More than
3m
More than
3m

None
None

Less than
50 %Less than
50 %

N. A.
Less than
50 %

Crown
Width

N. A.

All
All
All
All

Structure B•Multivariable logistic regression analysis
Multivariable analyses including all five structural

Figure 3.3.5.5 Schematic Diagram of thecharacteristics

Determination of Sections

wereconducted

in

order

to

compensate for possible false conclusions by the twogroup comparisons obtained when a sufficient numberof sample data was unavailable as a result of divisionof data into uniform-sized groups.
For the analyses, the following assumptions wereset:
A dike has a complete collapse probability varying
with the overtopping fluid force determined by the dike
structure;
For each 100 m-unit, a complete collapse occurs

Photo 3.3.5.2 Completely Collapsed Coastal Dike

independently of adjacent units.

(Ninokura Coast, Iwanuma City, Miyagi Prefecture)

A complete collapse probability of a section isdefined as the ratio of the number of completelyc) Analysis on structure-based difference in damage

collapsed units to the number of total units included in

Focusing on the five dike structural characteristics—

the section.

type of landward slope toe armoring, seaward slope

The distribution of the complete collapse probability

gradient, relative elevation of dike crown from175

PB is binomial because the event of collapse by outerCollapse Length Ratios
Within Each Category

1.0

forces has two-state values of “complete collapsed”
and “not collapsed,” expressed by the multiple logistic
model (1),

1

1 e

    1 X 1   2 X 2   n X n 

0.4

Where n denotes the number of elements used in
the analysis, variables X1 to Xn denote explanatory
variables representing the structural characteristic
values, α denotes a constant, and β1 to βn denotedikes (km)

7.6
1.1

16.7

(b)

0.8
0.6

Complete
Collapse

0.4
0.2

Partial andComplete Collapse

0.00coefficients.

Complete
Collapse
Partial andComplete Collapse

0.0
1.0

(1)
Collapse Length Ratiosof Each Section

PB 

23.2
16.5

18.1

0.6

0.2

in figure are(a) Numbers
total lengths of

11.5

0.8

2 4 6 8 10 12 14 16 18
Overtopping Water Depth（ｍ）

The multiple logistic model, which is one of the

Figure 3.3.5.6 Relation of Collapse Length Ratio tomultiple logistic analysis methods, frequently used in

Overtopping Water Depth

the medical field for the determination of diseasecauses, was applied to the probabilistic model-

It was confirmed that, except for the water depthbuilding of soil disaster occurrence by Kawagoe,

category of 16 to 20 m where a sufficient number of

7)

In the analysis, by the maximum likelihood

data was unavailable, the collapse length ratio

estimation method, the coefficients in the expression

generally increases as the overtopping water depth(1) were determined, and the influence of eachgrows. However, Figure 3.3.5.6 (b), where thestructural characteristic element was evaluated.

uncategorized data—raw data— is plotted, shows that

et.al.

the collapse length ratios are widely distributed even3) Result of damage analysis

for a certain overtopping water depth; for example,a) General features

while in a section having an overtopping water depth

In order to understand overall damage dataof 3 m, the complete collapse length ratio reached 100

characteristics, Figure 3.3.5.7 (a) was drawn using thepercent—all the dikes in the section were completely

measurements of all of the dikes that sufferedcollapsed—in other sections where the overtopping

overtopping, where the collapse length ratios (ratio ofwater depths were over 10 m, no dikes were

the total collapse lengths to the total dike lengths)

collapsed. Such a phenomenon would be the result of

were shown in relation to the overtopping water

the involvement of a variety of unknown factors such

depths. Note that the overtopping water depths wereas the duration time of overtopping, geographicalgrouped into seven categories—less than 2 m, 2 to 4 m,

conditions of backlands, or micro-structures of

4 to 6 m, 6 to 8 m, 8 to 12 m, 12 to 16 m, and 16-20

facilities; in addition, the collapse itself is a stochastic

m—and the calculation of the collapse length ratio was

event. Therefore, for grasping the general (averaged)

conducted within each category. Also note that thetrends, the data processing as shown in Figure 3.3.5.6

number of target sections was 225, the lengths of the(a) is helpful. On the other hand, the fluctuation

sections were distributed between 3 m to 3,756 m,

magnitude of data on damage severity is importantand the total length of all sub-coasts was 94.6 km.

information for disaster countermeasures planning;
therefore, such a graph as shown in Figure 3.3.5.6 (b)will be helpful and should be referred to during
practical operations.
b) Results of two-group comparisons for structuralcharacteristics

176Collapse Length Ratios
Within Each Category•Landward slope toe armoring
The investigation of 63 sections with a total lengthof 35.4 km focusing on the landward slope toe
armoring suggested that, for an overtopping water
depth of less than 12 m, toe armoring worked well to
lower the complete collapse length ratio, as shown in

1.0
0.8

1.5
1.9

1.1
0.2

0.9
0.8 6.0

0.0
0

2

0.3

8.8
4

6

Complete Collapse
With Gentler Slope

2.9
8Complete Collapse
With Steeper Slope

10 12 14 16

Overtopping Water Depth（ｍ）

Figure 3.3.5.8 Relation of Seaward Slope Gradient toshowed a similar tendency (Refer to Figure 3.3.5.7

Damage Severity (complete collapse cases)

(b)).
1.0

Numbers in figure (a) are total lengths of dikes (km) with seaward slope gradientsteeper than 50 percent [Gradient 1 : n, n = 0.90 ± 0.40 (mean ± s.d.), N = 25], andunderlined numbers are those of the other dikes [Gradient 1 : n, n = 2.52 ± 0.92
(mean ± s.d.), N = 26].

(a)

0.8
11.3

0.6

1.3

0.4

2.1

1.9

0.2 1.8 1.6
0.4 0.5 1.6
3.3
0.0
1.0

2.0

0.8

Complete Collapse
Without Armoring

0.3

Complete Collapse
With Armoring(b)Complete Collapse
Without Armoring

0.6

Complete Collapse
With Armoring

0.4

Envelope Curve
Without Armoring

0.2

Envelope Curve
With Armoring

1.0

Collapse Length Ratios
Within Each Category

Collapse Length Ratios
Within Each Category

0.02

0.4

Figure 3.3.5.6 (a). Investigations on each section

Collapse Length Ratiosof Each Section

11.1

0.6

6.0
0.6
0.4 0.9
0.2
0.0

0.8
0

1.1

8.8
1.9

Partial Collapse
With Steeper Slope

1.5

11.1
0.02

0.3

Partial Collapse
With Gentler Slope

2 4 6 8 10 12 14 16
Overtopping Water Depth（ｍ）

Figure 3.3.5.9 Relation of Seaward Slope Gradient to

0.0
0

2.9

0.8

Damage Severity (partial collapse cases)

2 4 6 8 10 12 14 16
Overtopping Water Depth（ｍ）

Numbers in figure (a) are total lengths of dikes (km) with seaward slope gradientsteeper than 50 percent [Gradient 1 : n, n = 0.90 ± 0.40 (mean ± s.d.), N = 25], andunderlined numbers are those of the other dikes [Gradient 1 : n, n = 2.52 ± 0.92
(mean ± s.d.), N = 26].

Figure 3.3.5.7 Relation of Landward Slope Toe
Armoring to Damage Severity
Numbers in figure (a) are total lengths of dikes (km) without armoring at the
landward slope toe, and underlined numbers are those of the other dikes.

•Landward slope gradient
The investigation on 28 sections with a total length•Seaward slope gradient
The investigation on 51 sections with a total lengthof 16.8 km, where only two groups—over-66.7-percent

of 35.4 km suggested that, at an overtopping watergroup and under-66.7-percent group—were compareddepth of 2 to 12 meters, the collapse length ratio, in

because of the small number of available samples,the cases of a seaward slope gradient gentler than 50

showed that, at an overtopping water depth of 4 to 12

percent, was lower than that in the cases of a gradient

meters, the under-66.7-percent group had a lower

steeper than 50 percent (Figure 3.3.5.8). However,complete collapse length ratio (Refer to Figure

focusing on the partial collapse cases—where dikes

3.3.5.10). However, the investigations focusing on

suffered damages but still stood—an inverse tendency

partial collapse cases showed that the under-66.7-

as shown in Figure 3.3.5.9 was found where thepercent group had a higher collapse length ratio; acollapse length ratio, in the cases of a gradient gentler

similar inverse tendency of collapse length ratio to thethan 50 percent, was higher.

tendency found in the cases of seaward slope
gradient was observed—the relation of the slope
gradient to the collapse length ratio in the complete
collapse cases shows an inverse tendency incomparison with the tendency in the partial collapse
cases (Figure 3.3.5.11).

177

Numbers in figure (a) are total lengths of dikes (km) of relative elevation frombackland ground over 3m [Relative elevation: 5.17 ± 1.79 (mean ± s.d.), N = 25],
and underlined numbers are those of the other dikes [Relative elevation: 1.95 ± 0.71
(mean ± s.d.), N = 34].

Collapse Length Ratios
Within Each Category

1.0
0.8

9.3
1.0

0.6

0.02

0.4

0.0

1.8

1.0

0.2

1.4

0.8
0

0.6

0.3

Complete Collapse
With Steeper Slopec) Results of multivariable analysis

Complete Collapse
With Gentler Slope

0.5

The multiple logistic regression analyses on the 170

246
8 10 12 14 16
Overtopping Water Depth（ｍ）

sections with a total length of 79.3 km suggested that
overtopping water depth, landward slope toe armoring

Figure 3.3.5.10 Relation of Landward Slope Gradientwidth, seaward slope gradient, and landward slope

to Damage Severity (complete collapse cases)

gradient significantly affect the complete collapse

Numbers in figure (a) are total lengths of dikes (km) with seaward slope gradientsteeper than 66.7 percent [Gradient 1: n, n = 1.07 ± 0.09 (mean ± s.d.), N = 15], andunderlined numbers are those of the other dikes [Gradient 1 : n, n = 1.55 ± 0.14
(mean ± s.d.), N = 11].

probability (Table 3.3.5.2). Note that, although therelative elevation is not statistically estimated to besignificant, its p-value is close to 0.05. The αcoefficient is -0.568.

Collapse Length Ratios
Within Each Category

1.0

The odds ratio shown in Table 3.3.5.2 is the

1.0

0.8

0.5

0.6
0.4

sensitivity of the complete collapse probability to an
0.6

1.8
0.8

0.2

0.02

0.0
0

1.0

9.3

explanatory

Partial Collapse
With Steeper Slope

1.4
0.3

variable;forexample,

when

the

overtopping water depth has an odds ratio of 1.3, aPartial Collapse
With Gentler Slope

one-meter increase in the overtopping water depth
makes the probability increase to 1.3 times the original2
4
6
8 10 12 14 16
Overtopping Water Depth（ｍ）

probability. A less-than-one explanatory variable’s

Figure 3.3.5.11 Relation of Landward Slope Gradientodds value means that the complete collapse

to Damage Severity (partial collapse cases)

probability decreases when the explanatory variable’s

Numbers in figure (a) are total lengths of dikes (km) with seaward slope gradientsteeper than 66.7 percent [Gradient 1 : n, n = 1.07 ± 0.09 (mean ± s.d.), N = 15],
and underlined numbers are those of the other dikes [Gradient 1 : n, n = 1.55 ± 0.14
(mean ± s.d.), N = 11].

value increases. As for the overtopping water depth,
landward slope toe armoring width, seaward slope
gradient, and landward slope gradient, the 95 percent
confidence interval for the odds value (95 % CI) does

•Relative elevation

not include 1 in it. Therefore, in terms of odds value,

The investigations on 49 sections with a total length

those five characteristic elements significantly affectof 7.9 km, focusing on the differences found in thethe complete collapse probability.

relative elevation of the dike crown from backland
ground, suggested as shown in Figure 3.3.5.12 that,at an overtopping water depth of 2 to 12 meters, theTable 3.3.5.2 Result of Multiple Logistic Regression

complete collapse length ratio in the cases of over-3-

Analysismeter relative elevation was higher than the ratio in

Explanatory
Variable(mean ± s. d.)
Overtoppingwater depth(5.8 ± 3.9 m)
Landward-slope
toe armoring
width(1.6 ± 3.1 m)
Seaward-slope
gradient 1: n
(1.7 ± 1.3)
Landward-slope
gradient 1: n
(1.5 ± 0.4)
Relative
elevation(3.5 ± 1.9 m)

the cases of under-3-meter relative elevation.

Collapse Length Ratios
Within Each Category

1.0
0.1

0.8
11.1

0.6

1.9

0.2
0.0

1.5

0.02

0.4

0.9 2.9 5.1 1.6
2.0
0

0.3

0.3

Complete Collapse
With High Elevation
Complete Collapse
With Low Elevation

24
6
8 10 12 14 16
Overtopping Water Depth（ｍ）

Figure 3.3.5.12 Relations of Relative Elevation from
Backland Ground to Damage Severity

178

βcoefficient

p-valueStandardized
Regression
Coefficient

Odds
Ratio
(95% CI)

0.261<0.0011.013

1.30(1.23-1.37)-0.264<0.001-0.8100.77(0.68-0.85)-0.3280.004-0.4360.72(0.57-0.90)-0.982<0.001-0.4030.37(0.23-0.61)

0.096

0.075

0.183

1.10
(0.99-1.22)

Crown width m(3.6 ± 2.3 m)

0.019

0.830

1.02
(0.84-1.18)

0.044

overtopping water.
b) Gradients of seaward slope and landward slope

The β coefficients for landward slope toe armoring
width, seaward slope gradient, and landward slope

With regards to slope gradients in the complete

gradient have negative values; this means that thecollapse cases, it is confirmed that a gentler gradientwider the landward slope toe armoring width is, theresults in a lower collapse length ratio as for either ofgentler the seaward slope, or that a gentler landward

the seaward slope or landward slope. However, thisslope leads to a lower complete collapse probability,

tendency is reversed with regard to the partial

consistent

two-group

collapse cases, a gentler gradient leads to a higher

comparisons for each structural characteristic element.

collapse length ratio. This suggests that a gentler

with

the

results

of

the

a

gradient did not directly reduce the tsunami force. A

compensated β coefficient normalized by the standard

gentler slope gradient is generally found in large-sizeddeviation of the explanatory variable for the purpose ofdikes; hence, the gentler slope effect could be acomparison of the explanatory variable’s influence

secondary one occurring by such a reason that a

power. In terms of overtopping water depth, landward

larger dike needs a longer time to completely collapse

slope toe armoring width, seaward slope gradient, or

and remains in a partially destructed state.

Thestandard

regression

coefficientislandward slope gradient, the absolute value for eachWith regard to slope armoring, the slopes with aof them grows in that order. This means that landward

gradient steeper than 50 percent are generally

slope toe armoring width has the most powerfularmored with a flat concrete coating or concrete slope

influence on the complete collapse probability among

frame, the slopes with a gradient gentler than 50

the five structural characteristic elements.

percent are generally armored with coastal protection
blocks that are not required to resist the hydrodynamic

4) Review and summary

force caused by tsunami overtopping water. Sucha) Landward slope toe armoring: positive effectblocks could easily be removed due to insufficient

The toe armoring width of 70 percent of the toeweight or unevenness and cause partial collapse ofarmoring treated in the two-group comparisons isthe dike. In addition, the behavior of overtopping water

narrower than 4 meters because all of the armored

could be heavily influenced by the slope gradient. In

toes, without regard for their width, were included in

the case of a seaward slope with a gradient steeper

the “armored toe group”. Although such width is very

than a certain value, water splashing occurs, and in

narrow compared to the width of the scouring caused

the case of an almost vertical landward slope, tsunami

by overtopping water, the result of two group analysis

water overtops the dike crown and goes off to havesuggested the effectiveness of toe armoring. The toe

almost no contact with the slope. The influence of thearmoring is estimated to have pushed the scoured

slope gradient on tsunami water’s behavior is, as

points far from the dike bodies. Therefore, toe

described above, so complex that the slope gradientarmored dikes are stronger even if their toes areshould be determined after careful investigations

armored in a very limited way.

through experiments and numerical simulations ofovertopping water’s behavior.

The results of the multivariable analysis indicatedthat landward slope toe armoring width is mostc) Relative elevation and crown width

effective among the structural elements. This result
was consistent with the hypothesis that the scouring

Relative elevation, although estimated by the two-at the landward slope toe triggers the destruction ofgroup comparisons to have positive influence on

the dike. Countermeasures for scouring at thecollapse probability, was not judged significant by the

landward slope toe are required with higher priority inmultivariable analyses. However, it is still a non-order to make dikes resilient against tsunami

negligible element when the confident interval of its pvalue or an odds ratio close to the significance level is

179takeninto

consideration,

becausetherelative

become a practically applicable model.

elevation could influence the magnitude of the energyof overtopping water colliding with the landward slope5) Summary

toe.

The analyses on the damages of three-surface

In terms of crown width, a sufficient variety of data

armored coastal dikes caused by the Great Eastfor the estimation of its effect was not available.

Japan Earthquake provided the following results andHowever, because a wider crown width leads to afurthermore strategies for the enhancement of thebigger body soil allowance against washout, crownresilience of facilities against tsunami overtopping

width should not be neglected even if no significant

water:

results are obtained by multivariable analyses.
a) Tsunami overtopping water depth was confirmed tod) Evaluation of resilience against overtopping water

be the main factor of the complete collapse of dikes.

Expression (1), when its variable coefficients are

However, large fluctuations were found in the relation

substituted by the coefficient obtained through thebetween such depth and collapse severity according

multivariable

numerical

to coast conditions. It is necessary to grasp the trend

evaluation of different structures. Figure 3.3.5.13, asin the relation of the maximum damage severity to thean example, shows how the complete collapse

depth of inundation water by using an envelope curve

probability varies as the overtopping water depth

for the purpose of disaster prevention.

analyses,enablesthegrows for several landward slope toe armoring widths.
This figure enables the evaluation of how much theb) Armoring of landward slope toes and gentler

widened landward slope toe armoring can reduce thegradients of seaward slopes and landward slopes iscomplete collapse probability against a certain

confirmed to contribute to the reduction of theovertopping water depth. We can estimate how muchprobability of complete collapse of dikes. Among them,

the resilience will be increased.

the armoring of landward slope armoring is the mostinfluential characteristic factor, and should be treated
preferentially. On the other hand, the slope gradient ofComplete Collapse
Probability

1.0

Width(0m)
Width(2m)
Width(5m)

0.8
0.6

a seaward or landward slope should be carefully
considered or treated because it was found to

0.4

contribute quite inversely according to the collapse

0.2

situation as complete or partial.

0.0
0

2

4 6 8 10 12 14 16 18 20
Overtopping Water Depth (m)c) Relative elevation can be estimated by the twogroup comparisons to contribute to the complete

Figure 3.3.5.13 Complete Collapse Probability Curves

collapse probability. A higher elevation leads to afor landward slope toe covering widths

higher complete collapse probability. On the other
hand, the multivariable analyses judged relative

Application of this model should be limited to theelevation to be a non-significant factor in the complete

range of the original data of the explanatory variables,

collapse probability.

because the abovementioned model is derived basedon the actual site data affected by a variety of

The “Committee for Technical Investigation on

structural conditions. In addition, the handling method

Coastal Countermeasures for Tsunamis,”of the explanatory variables in the model is notavailable analytic methods within the temporal

sufficiently validated. However, through a series oflimitations, has published a report recommending themodel experiments or accumulation of knowledge byfollowing three strategies for the construction ofnumerical simulations, the model is expected toresilient structures: (1) Preventing scouring at the

180

using

landward toe; (2) Preventing the loss of crownarmoring, landward slope armoring, or seaward slope

2) Keys to attaining a structure resilient against

armoring, and the washout of body soil: (3) Preventing

overtopping waterparapet wall fall-down. In addition, the analyses in thisThe previously mentioned Technical Bulletins

report reconfirmed the importance of landward slope

revealed the ideas and the key points for thetoe protection.

improvement of resilience against scouring and theIn the structural design considerations of resilient

stability of trapezoidal-shaped dikes; they are thecoastal dikes described below, landward slope toe

results of studies focusing on the scouring of landward

armoring and landward slope armoring will beslope toes and the stability of the landward slope

preferentially discussed following the abovementioned

armoring (Figure 3.3.5.14).

findings.
Improvement and points ofconcern regarding landward slope
armoring(3) Study on structures for resilient coastal dikes
1) Background

Countermeasures against
landward slope scouring
and its points of concern

The “Policies for Recovery of Coastal Levees
Damaged by the 2011 Great East Japan Earthquake
6)

and Tsunamis”

Figure 3.3.5.14 Diagram for the Illustration of Dike

prepared by the “Committee forPortions of concern

Technical Investigation on Coastal Countermeasure
for Tsunamis” listed the design strategies for resiliently

Major points of concern are the following:

functioning coastal dikes. Application of sufficient
thickness of landward slope armoring and armoring•High-speed currents around landward slope oron the landward slope toe were proposed to prevent

landward slope toe

landward slope washout and landward slope toe

The tsunami, when overtopping a coastal dike,scouring. The armoring landward slope toe was

generates high-speed currents around the landward

proved effective by the previously mentioned damage

slope or landward slope toe; in the model-based

analyses of dikes.

experiments, a high-speed current of over 10 m/s

Reconstruction of the damaged dikes will generally(scale-converted to actual dike size). Therefore,

be conducted by the affected prefectures, except for

countermeasures for the scouring and armoring loss

some portions of the Southern Coast of Sendai Bay,at the landward slope toe should be prepared.

Miyagi which will be reconstructed by the central•Countermeasures against the scouring of landward

government—the Tohoku Regional Development

slope toe

Bureau is in charge of a coast of about 30 km. For

The model-based experiments revealed such asuch reconstructions, more specific knowledge will betendency of the scouring at the landward slope toe

required on technical methods for the realization ofthat the scouring goes deeper as the overtopping

resilient structural design ideas previously mentioned.

water depth grows. An important countermeasure

In such situations, the River Department, NILIM, inagainst such scouring is to firmly protect the toe tocollaboration with the Seacoast Office, Water andhave the overtopping water pop up surely so that theDisaster Management Bureau, Ministry of Land,

scouring point goes far from the dike body; such

Infrastructure, Transport and Tourism, and the Tohoku

measure cuts off or retards the progression of theRegional Development Bureau, has been working on

collapsing process—the scouring of the toe leads tothe study of structural design improvement and thethe collapse of the dike body; as a result, thepoints of concern regarding the installation throughresilience of the dike body against the toe scouring ismodel-based experiments and mathematical analyses,

improved and the time to dike collapse will be

and publicized the results in the NILIM Technicalextended.

l8) and 9)

Bulletin

dated May 14 and August 10, 2012.

Figure 3.3.5.15 illustrates a proposed structure for181having the overtopping water pop up at the toe; theeven when significant surface unevenness exists,

key point is to completely alter the flow direction of thesuch drag surfaces that directly receive water forceswater stream coming down along the landward slope

will not be formulated. Figure 3.3.5.16 shows an

to such a direction (e.g. horizontal) that the water flow

example: the surface is covered with blocks having

will not collide with the ground. Note that the model

rabbets at both ends; they mutually engage in such aexperiments revealed that a relatively flat part which is

way that the upper block prevents the lower block

short compared to the water stream thickness will notfrom extruding.

sufficiently alter the stream direction, and that, on theother hand, an improved ground soil around the basesupports the base, and furthermore the improved partand the base work together in an integrated way as aprotection gear altering the stream direction to thehorizontal direction, makes the scouring point move
far from the toe, and finally lowers the occurrence
Figure 3.3.5.16 Improved Surface Cover Blockprobability of collapse starting.

•Generation of lifting forces

Change the flow
direction bylandward slopes

Lifting forces are suspected to be generated by thefollowing process:Landward
slope armoring
BacklandgroundA tsunami reaching a dike elevates the water levelat the seaward side of the dike;*: Length of flat part

Along with the lift of the water level, the seepage

Base work

face under the dike body begins to rise;

Figure 3.3.5.15 Proposed Improvement on Landward

Air is trapped between the rising seepage face andSlope Toe

the armoring. Such air entrapment occurs particularlyin the case where the armoring has an impermeable•Instability of a structure that occurs in a stream dueor hermetically sealed structure for the washout

to structure surface unevenness

prevention purpose, and in addition, even if theBumps made on the landward slope armoring

seepage face level is low, the pressure of thereceive a strong stream force and make the armor

entrapped air grows because the seepage face

instable.

effective

moves higher in a short period along with the risingcountermeasure is to remove unevenness on thewater level on the seaward side. Especially in thearmoring surface, or to adopt such a structure that thecase where the original water level—before theunevenness formulates no surfaces that directly

tsunami reaches—was high in the ground, thereceive the stream forces.

seepage surface reaches the dike bottom relativelyThissuggests

that

an

The following are the suspected causes of landward

faster.

slope surface unevenness: loss of soil under landward

The pressure of the entrapped air rises high enoughslope armoring; earthquake motions; and long-term

to prevent the seepage face from further rising, andvariations such as soil consolidation. However,

finally the entrapped air generates a dangerous lifting

because it is impossible to maintain a widely extended

forces on the armoring.

landward slope surface so flat that the surface canSuch lifting forces make the dike unstable.

have minimum unevenness when hit by tsunamis, it

Therefore, as shown in the following, the key to thewould be reasonable to improve the surface structure

countermeasure against dike instability is to make theso that, even when the dike body suffers deformations,armoring have air permeability for the purpose of

surface unevenness is suppressed to a minimum, or,preventing the entrapped air pressure from reaching a182

dangerous level by permitting the entrapped air to

Mechanics and Dynamics Research Team, Public

escape when the seepage face rises.

Works Research Institute.

•Landward side countermeasures against seepage
water level(5)

Dike structures should be improved so that theLandscapeassessment

commission

towardreconstruction of river or coastal structures

seepage water level is prevented from rising above a

In the three disaster-affected prefectures—Iwate,certain level, because if the seepage water level

Miyagi, and Fukushima—coastal dikes of 190 km outaround the landward toe is elevated so high, the waterof 300 km in total were completely or partiallygoing out can carry away the mud—the soil aroundcollapsed; in Sanriku district, the dike crown height will

the toe bottom, stirred up by water, turns into mud—be raised in accordance with the renewed design

causing damages to the toe. Such kind of atsunami height for dike construction; therefore, in

dangerous situation of soil washout, even if the water

those areas, new dikes, instead of recovery, have tolevel remains high for a short period, can be seen

be constructed; however, such new dikes will haveaccording to the soil conditions in the dike body or thelarger influences on the landscape than ever.

base, particularly when the overtopping water level

For the purpose of backing up the activities ofgoes down to the dike crown height—right after theassessing landscape changes accompanying thewater level reaches its maximum.

reconstructions• Necessity of countermeasures against negative

conductedpressures

prefectural governments, the Seacoast Office, Water

of

river

by theorcentralcoastalstructures

government

or

the

Negative pressures caused by the overtoppingand Disaster Management Bureau, Ministry of Land,

streams when tsunamis overtop the dike, greatly

Infrastructure, Transport and Tourism established thelower than the static pressure or even lower than the“Landscapeatmospheric pressure, can be generated around theReconstruction of River or Coastal Structures” tolandward side dike shoulder where the crowndiscuss and specifically prepare methods to consider

armoring contacts with the landward slope armoring.

landscape for the reconstruction of river or coastal

Countermeasure against such negative pressures are

structures; those method standards were included inrequired.

the “Guidebook for Landscape Consideration in theAssessment

Commission

towardReconstruction of River or Coastal Structures” and(4) Seismic design of coastal dikes“Annex: Example of Landscape Consideration in Case

The “Committee for Technical Investigation on
CoastalCountermeasurefor

Study Districts.” The following is an example of basic

Tsunamis”

consideration policies: on the dike line arrangement,

recommended, in the “Policies for Recovery of“Although, because the reconstruction of the facilities

Coastal Dikes Damaged by the 2011 Great East

stricken by the great earthquake will be conducted as6)

as follows:

one of the government-supported disaster recovery

coastal dikes should be designed so that the dikeprojects, the principle of reconstruction is the recovery

dose not suffer severe damage even during groundat the original location, it is important to determine themotions by an earthquake that cause the design

location and line-shape to the possible extent so thattsunami with an intensity of over level-one, and that,the landscape will be visually improved, the effects onafter the quake, the dike still has such structural safety

theand crown height that the dike endures tsunamis

sustainability will be preserved”; on the surface

hitting the dike after the quake.

finishing of slopes, mild rib patterns should be seen on

Japan Earthquake and Tsunamis,”

ecosystem

will

be

minimized,

and

the

For the purpose of supporting the recovery of

the straight and long dikes (accentuation by rib

affected areas, technical consultations such as

pattern) to give a “sense of stability” or “sense of being

seismic design reviews or advice on countermeasures

supported.”
Following the abovementioned policies, Miyagi

have been provided in collaboration with the Soil

183

Prefecture

andTohokuRegional

Official, Water Management & National Traffic

Development

Bureau established the Environmental Assessment

Maintenance

Department,

Committee for Recovery of River Mouths and Coastal

Development Bureau

TohokuRegional

Facilities in the Miyagi Coast to discuss, clarify, anddescribe the items of concern, and finally integrate the(Administration Office)results into a guidebook. Iwate prefecture has a plan

River Environment Division, Water and Disasterto establish a committee for the consideration ofManagement

Bureau,Ministryenvironment and landscape to discuss and prepare

Infrastructure, Transport and Tourism

of

Land,

River Improvement and Management Division, Water

prefectural guidelines. The Coast Division, NILIM, has

and Disaster Management Bureau, Ministry of Land,

participated in such committees as a member.

Infrastructure, Transport and Tourism
Disaster Management Division, Water and Disaster<Reference: Landscape Assessment Commission

Management

toward Reconstruction of River or Coastal Structures>

Bureau,Ministry

of

Land,

Infrastructure, Transport and Tourism(Timeline of discussions)
September 1, 2011: The 1st meeting

Seacoast Office, Water and Disaster Management

September 21, 2011:The 2nd meeting

Bureau, Ministry of Land, Infrastructure, Transport

October 14, 2011:

and Tourism

The 3rd meeting(Members)<Reference: Environmental Assessment Committee

Kunihiko Amano, Head, River Environment Division,for Recovery of River Mouths and Coastal Facilities inEnvironment Department, National Institute for Land

the Miyagi Coast>and Infrastructure Management(Timeline of discussion)
Friday, November 25, 2011: 1st meeting

Yuichi Kayaba, Head, Aqua Restoration Research

Thursday, February 9, 2012: 2nd meeting

Center, Public Works Research InstituteShinji

Sato,

Professor,

DepartmentofWednesday, March 7, 2012: 3rd meeting

Civil

Engineering, School of Engineering, The University(Members)of Tokyo

Masaki Sawamoto, Professor Emeritus, Tohoku

Yukihiro Shimatani, Professor, Kyushu University

University (Chair)

Gradual School (Chair)
Yoshio

Suwa,

Head,

Coast

Division,River

Department,

National

Institute

for

and

Land

YoshioHirano,Associate

Professor,

Division,River

Department,

National

Institute

for

and

land

Engineering, Department of Biological Engineering,
Ishinomaki Senshu University

Ataru Matsumoto, Director, River Section, Civil
Division,

Coast

Mitsuru Takasaki, Professor, School of Science andTohokuUniversity Graduate School
Engineering

Head,

Infrastructure Management

Infrastructure Management
Katsuya

Suwa,

Land

Tomo-o Takatori, Former Deputy Director, Sendai

Development

Science Museum

Department, Iwate Prefecture

Katsuo Takemaru, Director, Miyagi Branch, Wild Bird

Ryuichi Goto, Director, Rivers and Coasts Division,

Society of Japan

Civil Engineering Department, Miyagi Prefecture

Hitoshi Tanaka, Professor, Engineering, Tohoku

Norio Miyazaki, Director, River Improvement &University Graduate School

Maintenance Division, Public Works Department,

Toshihiko Naito, Doctor of Science, Miyagi plant

Fukushima Prefecture

Katsuya Hirano, Associate Professor, Information(Observers)

Science, Tohoku University Graduate School

Kazuhiko Saijo, Basin & Flood Control Adjustment

Akira

184

Mano,

Professor,

Engineering,TohokuUniversity Graduate School• Principally, the high-accuracy measurement dataobtained after the earthquake using instruments such

(Observers)

as laser profilers should be used as the geographic

Fisheries Infrastructure Department, Fisheries Agency

models in the simulations.

Private Forest Department, Tohoku Regional Forest•In simulations for predictions, damages of structures

Office, Forestry Agency

caused by ground motions or tsunamis are taken in

Northern Miyagi District Forest Office, Tohoku

account;

Regional Forest Office, Forestry Agency• Simulation outputs should include the horizontal

Sendai District Forest Office, Tohoku Regional Forest

distribution of maximum inundation depth and the off-

Office, Forestry Agency

the-coast directional distribution of maximum depth in

Maintenance Division, Tohoku Regional Agriculturala representative cross-section, in order to estimate theAdministration Officetsunami water inland invasion.

Disaster Management Division, Water and Disaster
Management

Bureau,Ministryof

In addition, the Coast Division of the NILIM started

Land

consultation

Infrastructure, Transport and Tourism

servicesontsunamiinundation

simulations, and held briefing sessions on the

Port and Airport Department, Tohoku Regional

abovementioned guide in 26 total affected cities,

Development Bureau

towns, and villages in July and August in 2011.

(Administration Office)(7) Guidelines on designing the assumptions ofRiver Section, Tohoku Regional Development Bureau,

tsunami inundation

Ministry of Land, Infrastructure, Transport and

The Law on the Development of Disaster-protected

Tourism

Communities

Rivers and Coasts Division, Miyagi Prefecture

requiresprefectural

governors

topredefine the tsunami-inundation prospect consistingof the areas expected to suffer tsunami inundation(6) Guide to tsunami inundation simulations

and the inundation water depth. The “Guidelines on
6)“Guide to Tsunami Inundation Simulations for

Designing the Assumptions of Tsunami Inundation” ,Planning Recovery Measures from the 2011 Greatco-authored by the Seacoast Office, Water and Land

11)

East Japan Earthquake” , co-authored by the CoastManagement Bureau, Ministry of Land, Infrastructure,

Office, Water and Land Management Bureau, MinistryTransport and Tourism, after the reviews by academicof Land, Infrastructure, Transport and Tourism,

experts, was released in February 2012. The guidedescribing the standard procedures for promptly

includes the following recommendations:conducting simulations for the purpose of backing up• The tsunami

the planning of recovery or rebirth of the affected

formulated according to the following order: definitionareas based on the analyses on the tsunami damagesofcaused by the Great East Japan Earthquake, after thecomputational

reviews by academic experts at the 2nd “Committee

simulations; extraction of inundated areas andforinundation water depth;

Technical

Investigationfor

Coastaltheinundation

maximum-classconditions;prospect should
tsunami;executionbeclarifyingoftsunamiCountermeasures for Tsunamis” held in June, was•The maximum-class tsunami should be defined forreleased in July 2011. The guide includes theeach set of coasts by choosing a tsunami whose

following recommendations:height is the highest among the past tsunamis that

• Principally,modelshad hit the set of coasts—applying the actual(validated models applicable to wide area analyses),

optimalgeographic

fault

observed height, simulated tsunamis—applying themodified so that the actual simulation outputs matchheights found in simulation outputs, and the tsunamis

the actual tsunami traces, should be used inthat are predicted to likely occur in future—thesimulations;predicted height;

185• The geographical fault model—it determines thefilling or cutting for making construction base grounds

initial height of tsunami, could be formulated by using,in the tsunami inundation risk areas, and the technical

as a reference if available, the geographical fault

requirements of tsunami protection facilities weremodels validated by the authorities such as thediscussed as follows at the “Technical Review

CentralCommittee on the Regional Development in Tsunami

DisasterPrevention

Council

or

the

7)

Headquarters for Earthquake Research Promotion;

Disaster” . This committee was chaired by Prof. Shoji• Principally, the simulations for the definition of

Fukuoka, Chuo University, consisting of technicaltsunami inundation prospect should be conducted

experts and administration officials, where the Coast

under such an assumption that a maximum-class

Division, River Department, NILIM, jointly with thetsunami could always occur under an unfortunately

Seacoast Office, Water and Land Management

bad condition and cause inundations with damages to

Bureau, served as the administration office.

facilities induced by earthquakes and tsunamis. Do
not forget the lesson that “no upper limitation exists for

1) Evaluation of tsunami water heading up against

the severity of a disaster.” Do not forget that “savingbuildings
Prefectural governors are required to publicly

life is the first and the ultimate goal”;• For clear estimations of the inland invasion ofannounce the reference water level (inundation watertsunami water, tsunami inundation simulations mustlevel including the heading up height of tsunami

output the maximum predictable inundated areas andwater) when setting the tsunami disaster warning

water depths.

areas or the special tsunami warning areas. Mayors ofthemunicipalities designate the facilities in the tsunami

targetingdisaster warning areas as the authorized shelters that

prefectural governments and construction consultants

satisfy the requirements set by using the referencein February and March 2012. Also, since April 2012,

water levels. Furthermore, according to one of the

Q&A and request-for-comment sessions have been

permit requirements of the development of social

held, participated in by the officials in charge from thewelfare facilities, schools, and medical facilities, etc. in

prefectural governments concerned and the regional

special tsunami disaster warning areas (hereinafter

development bureaus concerned.

referred to as “special designated development”),

Inaddition,briefing

abovementioned

guidessessions
were

on

held

those facilities are required to have floors higher than
(8)

Technical

review

concerningthethe reference water levels.

regional

Such a reference water level is recommended to be

development in tsunami disaster

equal to the maximum value of specific energy at the

The Ministry of Land, Infrastructure, Transport andTourism discussed the regional development ingrid

tsunami disaster after the tsunami damages in thesimulations; its validity has been confirmed during

Great East Japan Earthquake, and established the act

tsunamion regional development in tsunami disaster. This act

buildings, and examined by using the actual tsunami

promotes the following activities, based on the

trace heights.
The

concept of “multi-leveled protection” consisting of apointsobtained

inundationbytsunamisimulations

abovementioned

inundation

includingvirtualrecommendations

were

mixture of hardware-oriented protection measuresincorporated into the “Basic Policies for Promotion ofand software-oriented measures: development ofRegional Development in Tsunami Disaster” (January

tsunami16, 2012, Announcement No.51, Ministry of Land,

protection

facilities;

restriction

of

land

Infrastructure, Transport and Tourism)

development or construction; and preparation oftsunamiwarningandevacuation

framework.
2) Technical requirements of land-filling or cutting

Particularly, the methods of estimation of heading upof tsunami water on the fronts of buildings possibly

The technical discussion group, with regard to theused for shelters, the technical requirements of land-

special designated developments, worked out the186following recommendations on the requirements ofNovember 8, 2011: 1st meetingslopes resulting from land-filling or cutting so that theirNovember 28, 2011: 2nd meeting

safety is secured against tsunami inland invasion:

December 9, 2011: 3rd meeting•Slopes not protected by retaining walls should be

January 11, 2012:

4th meetingarmored with grass instead of mortar coating (thisrecommendation was derived from the estimation by(Members)

the slope erosion depth by tsunami inundation<Experts>

simulations)Shinji

Sato,

Professor,

Department

of

Civil

Engineering, Tokyo University Graduate School• Against the scouring of the slope toe, stability

Shojianalysis assuming a circular slip should be executed

Fukuoka,

Professor,

ResearchandDevelopment Initiative, Cho University (Chair)by application of the maximum possible scouring
depth, and either of the two protection measures,

Koji Fujima, Professor, Department of Civil andprotection armoring or forming setbacks on the filled

Environmental Engineering, School of Systems
Engineering, National Defense Academy

or cut, should be adopted.

Mikio Futaki, Director, Tsukuba Construction Test

•Because there is a risk of erosion of a slope’s top-

Center for Better Living

ends by overtopping tsunami water, countermeasurescompatible with the requirements of low-water river<Administrative Officials>

revetment crowns should be applied.
The

abovementioned

recommendations

Ataru Matsumoto, Director, River Section, Civil

were

incorporated into “About the effectuation of the act on

Engineering

Division,Land

regional development in tsunami disaster (Chapter 9)”

Department, Iwate Prefecture

Development

Ryuichi Goto, Director, Rivers and Coasts Division,(July 31, 2012, Effectuation Notice by the Director of

Civil Engineering Department, Miyagi Prefecture

City Bureau, Director of Water and Land Management

Takuo Chiba, Director, Building Grounds Division,

Bureau and Director of Housing Bureau).

Civil Engineering Department, Miyagi Prefecture3) Technical requirements of tsunami protection

Toshikazu Asano, Director, River Planning Division,facilities

Public Works Department, Fukushima Prefecture

A tsunami protection facility is defined as follows: a

Kazuhiko Murata, Director, Urban Development

facility for the purpose of saving human life in

Department, Hamamatsu City

maximum-class tsunamis functioning as a protection
against tsunami inundation inland invasion, including<Administration Office>structures of land filling, revetments, breast walls, andWater and Disaster Management Bureau, Ministry oflockage.

The

recommendations

on

Land,

technical

Tourismand Tourism (Urban Development Control Office

performance or capacity.

and City Planning Division)

The recommendations were incorporated into theRiver Department, National Institute for Land andenforcement regulation of the act on regional

Infrastructure Management (Coast Division)development in tsunami disaster (December 26 2011,
No.

and

City Bureau, Ministry of Land, Infrastructure, Transport

the durability capacity, and then the points of review ofordinance

Transport(Seacoast Office and River Planning Division)requirements describe the functional performance andMinistry

Infrastructure,99,

MinistryofLand,
Acknowledgements

Infrastructure, Transport and Tourism)

The authors acknowledge that, as for the provision<References: Technical Discussion Group for theof the technical consultation services described in thisDevelopment of Tsunami Protected Communities>

report, the authors were greatly supported by the(Timeline of meetings)

Coast Office, Water and Land Management Bureau,

187

MLIT

on

the

technical

discussions

and

the

3) Imamura,

Fumihiko:“Manualfor

Tsunamicoordination with the regional offices or technical

Damage Investigation”: Tsunami Engineeringexperts. The authors express thanks for their support.

Report 15: 1998: p.p. 107-117

The materials such as the master list of coast4) Tohoku Earthquake Tsunami Joint Survey Group:

protection facilities used in the analysis of dike<http://www.coastal.jp/ttjt/index.php>: 2011-08-26

damages were collected during the investigations by5) Watanabe,

Isao:“NihonTsunamiSo-Ran”

the “Committee for Technical Investigation on Coastal(Comprehensive List of Tsunamis and TheirCountermeasures for Tsunami.” The authors express

Damages in Japan). Tokyo University Press,

thanks to Aomori, Iwate, Miyagi, Fukushima, Ibaraki,

1998: p. 238

and Chiba Prefectures, and the Tohoku Regional

6) Committee for Technical Investigation on Coastal

Development Bureau for their kindness in providing

Countermeasures for Tsunamis: “Basic Policies

the reports of damage situation investigation. The

for Recovery of Coastal Dikes, etc. damaged byauthors also express thanks to Alpha Hydraulic

the Tsunamis in the 2011 Off the Pacific Coat ofEngineering

Consultants,

Co.

Ltd.,

for

their

Tohoku Earthquake”: 2011: p. 9

cooperation in the re-measurements of fishery areas.
Theauthors

express

thankstothe7) Kawazoe,

River

Seiki,

So

Kazama,and

Masaki

Sawamoto: A Probability Model of Sediment

Department, Iwate River and National Highway Office,HazardSendai National Highway Office of Tohoku Regional

Information and Extreme Precipitation Data,

Development

Journal of Natural Disaster Science, vol. 27 (1),Bureau,andLand

Development

Department of Iwate Prefecture for their cooperation

Based

on

Numerical

Geographic

2008: p.p. 69-83

in the site investigations.

8) River Department, National Institute for Land andInfrastructure Management, Ministry of Land,

References

Infrastructure, Transport and Tourism: “Study on1) Central Disaster Prevention Council: Report of the

Resilient Structures for Coastal Dikes (1stCommittee

forTechnical

Investigationon

Report)”: NILIM Technical Bulletin, No.1, 2012: p.

Countermeasures for Earthquakes and Tsunamis

12

Based on the Lessons Learned from the “2011 off

9) River Department, National Institute for Land andthe Pacific coast of Tohoku Earthquake”: 2011: p.

Infrastructure Management, Ministry of Land,

44

Infrastructure, Transport and Tourism: “Study on2) Director, Disaster Management Division, Rural

Resilient Structures for Coastal Dikes (2nd

Infrastructure Department, Rural Development

Report)”: NILIM Technical Bulletin, No.3, 2012: p.

Bureau, Ministry of Agriculture, Forestry and
Fisheries;

Director,

21

Communities

10) Water and Land Management Bureau, Ministry of

Promotion and Disaster Prevention Division,

Land, Infrastructure, Transport and Tourism:

Fisheries Infrastructure Department, Fisheries“Guidelines

Agency;Director,

Conservation

Fishing

Seacoast

Division,

Sabo

Bureau,LandscapeAssessment

for

Office,Land

Reconstruction of River or Coastal Structures”:(Erosionand2011: p. 37

Sediment Control) Department, Water and Land
Management

for

Ministryof11) Coast

Division,River

Department,

National

Land

Institute for Infrastructure and Land Management,

Infrastructure, Transport and Tourism; Director,

and Water and Land Management Bureau,

Coast Administration and Disaster Reduction

Ministry of Land, Infrastructure, Transport andDivision, Ports and Harbours Bureau, Ministry of

Tourism:“GuideLand, Infrastructure, Transport and Tourism.

Simulationsfor“About the Method of Setting Design Tsunami

Damages in the 2011 Off the Pacific Coast of

Water Level”: Official Notice, July 8, 2011

Tohoku Earthquake” 2012: p. 22

188

to

TsunamiInundation

Countermeasuresagainst12) Coast

Division,River

Department,

National

Institute for Infrastructure and Land Management,
and Water and Land Management Bureau,
Ministry of Land, Infrastructure, Transport andTourism: “Guide to Setting Tsunami Water
Inundation Proposition”: 2012: p. 77
13) Technical Discussion Group on the Developmentof Tsunami-Protected Communities: “Technical
Report on the Development of Tsunami-Protected
Communities”: 2012: p. 62

189

3.3.6 Roads

verification of the seismic reinforcement measures(1) Initial Response (TEC-FORCE, etc.) and Surveys

and technical standards implemented hitherto. Inof the Extent of the Disasterterms of the extent of the damage to road

Immediately after the Great East Japan Earthquake

infrastructure, according to a report by the Water andstruck, the Bridge and Structures Division of the Road

Disaster Management Bureau of the MLIT , theDepartment and the Earthquake Disaster Prevention

number of points of damage to civil engineering

Division of the Research Center for

Disasterinfrastructure in the Tohoku and Kanto regions

Management at NILIM began to work in partnershipresulting from disasters during FY2011 (it should bewith the Center for Advanced Engineering Structural

noted that this includes damage resulting from

Assessment and Research (CAESAR) at the Publicdisasters

Works Research Institute (PWRI), conducting surveys

Earthquake) was 372 in the case of road infrastructureof bridges along national highways, prefectural roads,

on national highways managed by MLIT, 12,654 in theand municipal roads in the prefectures of Iwate,case of road infrastructure on roads managed by

Miyagi, Fukushima, Tochigi, Ibaraki, Chiba, andprefectural and municipal governments, and 542 in

Kanagawa. In conducting these surveys, as well as

the case of bridges managed by prefectural andproviding technical advice to road administrators

municipal governments. Moreover, in relation to traffic

concerning such matters as earthquake-resistanceobstructions due road infrastructure being damaged

diagnosis of bridges and repair methods, theas a result of the Great East Japan Earthquake, theresearchers gathered information to facilitate theCabinet1)(a) Numata Overpass

other

Office

than

has

the

Great

reportedthat(b) Namiita Bridge(c) Asahi Elevated Bridge(d) Koizumi Bridge

Photo 3.3.6.1 Photographs of Surveys Being Conducted

190

East

there

Japan

were

obstructions at 4,200 points due to road damage, and2)

at 116 due to bridge damage .
The objective of most of the surveys conducted at
the time of the initial response was to provide
technical support, mainly in response to requests fromroad administrators; the subsequent surveys wereindependent studies conducted for the purpose ofdeveloping technical standards in relation to tsunami
and verifying earthquake-resistance standards. 218
bridges were surveyed (of which, 106 were surveyed
by NILIM), with surveys taking a total of 280 man-days(of which, 59 man-days were contributed by NILIM,
not including time traveling to and from the region).
Figure 3.3.6.1 shows the bridges surveyed. This map
also includes bridges surveyed independently by the
PWRI.

191

During the initial response, TEC-FORCE Unit 1

information about the extent of the damage to civil

departed for the headquarters of the Tohoku Regional

engineering structures was non-existent, extensive

Development Bureau on the evening of March 11,

damage was anticipated, based on reports such as2011, the day of the disaster; the unit was sent at theearthquake early warnings. Accordingly, even while

Bureau's request, which was channeled to NILIM via

en route to the region concerned, it was unclear

the National Highway and Risk Management Division

whether it would be possible to reach the Tohoku

of the Road Bureau, MLIT. At this point, although

Regional Development Bureau headquarters, let

Omoto Bridge
Masaki Bridge

Hanamakiminami Bridge
Showa Bridge

Miyako Bridge

Kitakami-Chuo Bridge
Hitakami Bridge

Kanahama Overpass

Horai Bridge
Sannohashi Bridge
Owatari Bridge

Kunen Bridge
Kunimi Bridge
Ezaki Bridge
Kanegasaki Bridge
Shiushi Bridge

Tenjin Viaduct

Ohamawatari Bridge

No.1 Arakawa Bridge

Yanoura Bridge

Takiirigawa Bridge

Omagari Bridge
Ushizawa Bridge
Sakunose Bridge
Ichinoseki Bridge
Arikabe Overpass

Namiita Bridge

Kashi Overpass
Arakawa Overpass
Ryoishi Bridge(Minami Wharf)

Koyagi Bridge
Fuji Bridge

Orikasa Bridge

Kamaishi Viaduct
Taihei Bridge
Hirata Bridge

Aneha Bridge

Katagishi Bridge
Arakawa Bridge

Nanakiri Overpass

Shirakizawa Bridge

Takada Overpass
Kawaharagawa Bridge

Numata Overpass
Hamadagawa Bridge

Kesen Bridge

Matsubara Bridge

Furukawa Bridge

Nagisa Bridge
Nashinoki Bridge

Kurihara-Chuo Bridge

Koizumi Bridge

Uchiminamizawa Overpass

Sodeogawa Bridge
Nijyuichihama Bridge

Minamisawagawa Bridge

Utatsu Bridge
Shiomi Bridge

Takashimizu Bridge
Shinmaiya Bridge
Unclear (area around
Unclear (area around
Oritate Bridge (1 bridge)) Yokotsu Bridge (7 bridges))

Mizujiri Bridge
Oritate Bridge
Yokotsu Bridge(Annotated version of background map data distributed by the Digital Japan Web System, Geospatial Information Authority of Japan)

Figure 3.3.6.1 Location Map of Bridges Surveyed (1)192alone the areas actually affected by the disaster.
However, due to the pressing need to provide support
for the clearance of blocked roads and gain a prompt
understanding of the extent of the damage to roadstructures, which play a vital role in rescue operations
by facilitating emergency transport, as well as being
crucialinfrastructure

supporting

recoveryandreconstruction activities, the team single-mindedlypressed on toward the disaster-stricken areas. They
arrived at the headquarters of the Tohoku Regional
Development Bureau late at night on the day of thedisaster and, having assembled information about theextent of the damage that had arrived from each office,they commenced surveys in the disaster-stricken
areas at dawn the following day.

193

Noda Bridge

Shin-Eaigawa Bridge

Kimazuka Bridge

Ipponyanagi Overpass(Kamiwakuya Bridge)

Eai Bridge

Kanon Bridge

Unclear (area around Takihama
in Minamisanriku (4 bridges))

Nagashizu Bridge
Shin-Aikawa Bridge

Shida Bridge
Tadagawa Bridge

Shin-Kitakami Bridge

Sendai-Hokubu Road
Rifu ViaductTenno Bridge

Miyagino Bridge
Sendai Bridge
Natori Bridge

Onosaki Bridge
Fujikawa Bridge
Shin-Iinogawa Bridge
Shin-Tenno Bridge
Onagawa Bridge

Unclear (area around
Onagawa Bridge (5 bridges))

Kasuminome Footbridge
Nakanose Bridge

Hiyori Bridge
Sadakawa Bridge
Sendai-Tobu Road
Tobu Viaduct

Tsukinoki Viaduct

Higashine Bridge

Yuriage Bridge

Takamatsu Bridge
Naruse-Okumatsushima Bridge

Naruse Bridge

Bridge to the north of the
Rachihama water treatment plant

Akebono Bridge
Udagawa Bridge(Annotated version of background map data distributed by the Digital Japan Web System, Geospatial Information Authority of Japan)

Figure 3.3.6.1 Location Map of Bridges Surveyed (2)194

Taisho Bridge
Shimizu Bridge
Izumi Viaduct
Azuma Viaduct
Kamata Bridge
Osaragi Bridge

Tenjin Bridge

Tonda Overpass

Sasaharagawa Bridge

Kameda Bridge
Kinzan Pedestrian Bridge

Sugakawaminami Bridge
Taira Overpass
Misawa Bridge
Yumoto Overpass
Sekibune Overpass
Yadagawa Bridge

Kasaishi Overpass
Tamachi Bridge
Fukushima Airport IC: arch
culverts and other structures

Shin-Naka Bridge

Mimaya Tokuhime Overpass

Rokujumai Bridge
Iwakimaiko Bridge
Nametsu Bridge

Yoshikawa Bridge

Daini Hojuingawa Bridge

Izumi Overpass
Ueda Overpass
Shibukawa Bridge
Eguri Bridge

Rokumaiuchi ViaductMiyanoshita ViaductNo.1 Odairagawa Bridge

Samekawa Ohashi Bridge

Samekawa Bridge

Transverse box culvert at Kamasusaka

Omiya Overpass

Kyu-Samekawa Bridge
Takato Bridge
Asahi Viaduct
Satogawa Bridge

Sakae Bridge

Shizu Overpass
Daikei Bridge

Hatasome Bridge

Koishikawa Bridge
Sakiku Bridge

Takajo Bridge
Sendai Bridge
Kaso Bridge
Shin-Fujimi Bridge
Shimodate Overpass
Sakae Bridge
Kinugawa Bridge
Shimotsuma Overpass
Mayu Bridge
Ishige Bridge
Shin-Fukurai Bridge
Mitsuma Bridge
Yatagawa Bridge
Mitsukaido Bridge
Ichicawa Bridge
Area around the Sakai River, Urayasu(area with liquefaction)
Akemi Bridge
Takasu Bridge
Irifune Bridge
Imagawa Bridge
Sakaigawa Central Footbridge
Sakaigawa East Floodgate
Akebono Bridge

Nakagawa Bridge
Kunita Bridge
Bandai Bridge
Umeto Bridge
Tsukuba Overpass
Ota Bridge
Oshito Bridge
Katsuta Bridge

Ishinazaka Bridge
Momiyakawa
BridgeShin-Nakagawa Bridge
Shin-Nakamaru Bridge
Minato Bridge
Kaimon Pedestrian Bridge

Higashisuijin
BridgeRokko Bridge

Tadobe Overpass
Kasumigaura Bridge

Rokko Bridge
Kitaura Bridge
Inashiki Bridge
Yokotone Bridge
Kanzaki Bridge

Sakai Bridge
Fureai Bridge
Kitaura Bridge
Horai Bridge
Hokota Bridge
Fuji Bridge
Jingu Bridge
Shin-Jingu Bridge
Kitatone Bridge
Itako Bridge

Nakahama Bridge
Isobe Bridge
Mihama Bridge

Shuto Expressway Arakawa Bay
BridgeShuto Expressway
Daikoku Junction

Yokohama Bay Bridge(Annotated version of background map data distributed by the Digital Japan Web System, Geospatial Information Authority of Japan)

Figure 3.3.6.1 Location Map of Bridges Surveyed (3)195As the extent of the disaster - particularly the extent

Development Bureau (not positioned as a TEC-of the damage caused by the tsunami - became clear,

FORCE request). NILIM's response (TEC-FORCE,

technical advice began to be required concerning thetechnical consultations, etc.) in relation to roadpotential for temporary repair of bridges damaged bystructures damaged by the Great East Japanthe tsunami and the use of temporary bridges inEarthquake is shown in Table 3.3.6.1. In order toplaces where the bridge piers remained, as well as

conduct field surveys of road bridges in response toadvice about the repair methods that could be used,

requests from road administrators, 6 teams wereso there were ongoing requests for TEC-FORCE's

dispatched to the Tohoku Regional Development

presence, which NILIM handled. In doing so, NILIM

Bureau, 1 team to Ibaraki Prefecture, 1 team to Iwate

worked in collaboration with CAESAR, the assistancePrefecture, and 1 team to Chiba Prefecture. Inof which had been requested by the Tohoku Regional

addition, the activities conducted by TEC-FORCE

Table 3.3.6.1 List of Response Measures Implemented by NILIM (TEC-FORCE, Technical Consultations, etc.) Concerning Damage to Road Structures from the Great
East Japan Earthquake (1)Date

Response

2011
March 11-12
March 14-15

TEC-FORCE(Tohoku Regional Development Bureau)
TEC-FORCE(Tohoku Regional Development Bureau)

March 16-17

Field survey at the request of Ibaraki Prefecture

March 17-18

TEC-FORCE(Tohoku Regional Development Bureau)

March 29

TEC-FORCE(Tohoku Regional Development Bureau)
Ibaraki Prefecture Investigative Committee on
Emergency Repair
Independent survey
TEC-FORCE(Tohoku Regional Development Bureau)(i) TEC-FORCE(Tohoku Regional Development Bureau)

March 31
April 6
April 6
April 14-15

April 20
April 26
May 13
May 15June 1
June 3June 29

August 10(ii) Field survey at the request of Iwate
Prefecture
Field survey at the request of Chiba City
Independent survey
Technical consultation (Iwate Prefecture)
Independent survey
Technical consultation (Ibaraki Prefecture)
Independent survey
Tohoku Regional Development Bureau
Investigative Committee (1st Meeting)Tohoku Regional Development Bureau
Investigative Committee (2nd Meeting)

Bridges Surveyed
Miyagino Bridge, Naruse Bridge, Tenno Bridge, Shin-Tenno Bridge,
Shin-Iinogawa Bridge, Tadagawa Bridge
Namiita Bridge, Namiita Pedestrian Bridge, Ohamawatari Bridge,
Orikasa Bridge, Horai Bridge, Horai Pedestrian Bridge, Miyako
Bridge, Omoto Bridge, Masaki Bridge, Kanahama Overpass,
Kameda Bridge
Takado Bridge, Satogawa Bridge, Hatasome Bridge, Omiya
Overpass, Shizu Overpass
Kesen Bridge, Numata Overpass, Kawaharagawa Bridge,
Hamadagawa Bridge, Nanakiri Overpass, Takada Overpass, Aneha
Bridge, Furukawa Bridge, Matsubara Bridge, Nagisa Bridge
Osaragi Bridge

Total Mandays
2 man-days
4 man-days

4 man-days
6 man-days

2 man-days

Shizu Overpass, Satogawa Bridge, Hatasome Bridge, Kunita Bridge

1 man-day

Sendai-Tobu Viaduct
Ezaki Bridge, Kanegasaki Bridge, Kunimi Bridge, Kunen Bridge

1 man-day
1 man-day(i) Mizujiri Bridge, Utatsu Bridge, Nijyuichihama Bridge, Sodeogawa
Bridge, Koizumi Bridge, Shiomi Bridge, Kesen Bridge, Aneha
Bridge, Kawaharagawa Bridge, Furukawa Bridge, Numata
Overpass(ii) Koyagi Bridge
Mihama Bridge, Isobe Bridge, Nakahama Bridge
Shiushi Bridge, Koyagi Bridge, Fuji Bridge, Omagari Bridge
Koyagi Bridge
Yokohama Bay Bridge (R357)
Kunita Bridge
Koizumi Bridge, earthworks structures around the city of Kurihara
Ipponyanagi Overpass, Shin-Eiaigawa Bridge, Kashi Overpass,
Ushizawa Bridge, Katagishi Bridge, Arikabe Overpass, Ichinoseki
Bridge, Koizumi Bridge, Utatsu Bridge
Samekawa Bridge, Naruse Okumatsushima Bridge, Tenno Bridge,
Rokumaiuchi Elevated Bridge, Osaragi Bridge, Ueda Overpass,
Kameda Bridge, Daini Hojuingawa Bridge, Udagawa Bridge, Miyako
Bridge, Kinzan Pedestrian Bridge, Miyama Tokuhime Overpass,
Izumi Viaduct, Okeba Bridge

6 man-days

196

3 man-days
1 man-day
4 man-days
2 man-days
2 man-days
5 man-days
1 man-day

1 man-dayTable 3.3.6.1 List of Response Measures Implemented by NILIM (TEC-FORCE, Technical Consultations, etc.) Concerning Damage to Road Structures from the Great
East Japan Earthquake (2)Date

Response

Total Mandays
6 man-days

Bridges Surveyed

August 25-26

Independent survey

September 29

Tohoku Regional Development Bureau
Investigative Committee (3rd Meeting)

October 20-21

Independent survey

November 24

Technical consultation (Tohoku Regional
Development Bureau)
Technical consultation (Ibaraki Prefecture)

Oritate Bridge, unclear (area around Oritate Bridge (1 bridge)),
Yokotsu Bridge, unclear (area around Oritate Bridge (2 bridges)),
Unclear (upstream of Yokotsu Bridge (5 bridges)),
Unclear (area around Takihama in Minamisanriku (4 bridges)),
Nagashizu Bridge, Shin-Kitakami Bridge, Onosaki Bridge, Onagawa
Bridge, Unclear (area around Onagawa Bridge (5 bridges))
Tadagawa Bridge, Natori Bridge, Ryoishi Bridge, Ichinoseki Bridge,
Kameda Bridge, Azuma Elevated Bridge, Ipponyanagi ElevatedBridge, Arikabe Overpass, Shiomi Bridge
Tsukinoki Viaduct, Natori Bridge, Yuriage Bridge, Nakanose Bridge,
Taisho Bridge, Osaragi Bridge, Kameda Bridge, Izumi Viaduct,
Shimizu Bridge, Tenjin Bridge, Kamata Bridge
Ichinoseki Bridge, Naruse Okumatsushima Bridge

1 man-day

2 man-days

2 man-days

2012
Asahi Viaduct
2 man-days
January 30
Note 1: The total man-days refers solely to NILIM staff.
Note 2: Excludes surveys, etc. conducted singlehandedly by the PWRI.
Note 3: The Tohoku Regional Development Bureau Investigative Committee is the Investigative Committee on the Repair of Bridges Damaged by the Great East Japan
Earthquake, described in (3) below.

often went on late into the night, so a 24-hour

and Risk Management Division of the Road Bureau

logistical support system was adopted by the researchissueddivisions, to provide information to the staff members

Development Bureau and other bodies, entitleddispatched to areas affected by the disaster and toConcerning Inspection of Road Infrastructure (April 14,

serve as a point of contact for the Ministry and the2011; National Highway Risk Management Divisiondisaster prevention coordinator in the Planning

Notice No.3). Furthermore, an administrative circular

Division at NILIM.

entitled Concerning Emergency Inspection of RoadanadvisorytotheTohokuRegional

Starting with the initial response, NILIM has

Infrastructure (April 20, 2011; Administrative Circular

conducted a number of rounds of independent

from the Deputy Director) was issued to serve as asurveys,anpoint of reference when conducting these emergency

understanding of the extent of the damage andinspections. Consisting of two parts, one subtitledobtaining the data required to analyze the causes ofBridges, and the other Soil Structure and Slopes, thisthe damage and determine the necessity of revisingadministrative circular specified matters relating to3)

relevant technical standards. See the previous report

methods of inspection, the evaluation and recording offor details of the distinctive aspects of the damage.

the results of emergency inspections, and major(2) Emergency Inspection of Road Infrastructure

points on which to focus and things to bear in mind in(Conducted by Regional Development Bureaus)

conducting inspections. Working in partnership with

with

the

objectiveofgaining

One of the characteristics of the Great East Japan
Earthquake

is

the

fact

that

numerous

CAESAR, the Bridge and Structures Division tooklarge

charge of the task of writing the original draft for theaftershocks continued for quite some time afterwards.

Bridges part of this administrative circular. The PWRI

As of October 16, 2012, aftershocks measuring

was responsible for writing the original draft of the part

magnitude 5.0 or higher had been recorded on 818

entitled Soil Structure and Slopes. In response to this4)

occasions . Moreover, on April 7, 2011, an aftershock

administrative

circular,of a scale comparable to the main quake occurred,

Development

Bureauwith a magnitude of 7.2 and a seismic intensity of 6-

emergency inspections.

upper. Due in part to this fact, the National Highway

theTohokuimmediately

Regional

carriedout

NILIM received the results of the emergency

197

inspections that the Bureau had conducted, andtsunami.

carried out correlation analysis concerning the extent

established on the basis of the judgment that it wouldof the damage and the various contributory factors. An

be more efficient to set up a formal organization when

example of the results of this analysis is shown inreceiving technical support from NILIM and the Public

Figure 3.3.6.2. The damage rate in bridges that had

Workssustained seismic motion of at least 6-lower on therequests in relation to each individual bridge.

This

Research

Investigative

Institute,

Committee

ratherthan

wasmakingseismic intensity scale used by the Japanese

The objectives, affairs under the jurisdiction of the

Meteorological Agency (JMA) was in excess of 50%.

committee, and members are shown in Table 3.3.6.2,

Moreover, incorporating both issues that surfaced inwhile an overview of its meetings is provided in Table

conducting these emergency checks and insights

3.3.6.3. Tireless efforts aimed at recovery andgained from reflecting on similar emergency checks inreconstruction are currently underway, based on thethe past, the Manual on Emergency Checks andtechnical advice provided during meetings of thisSurveys of Road Bridges in the Event of Disaster

Investigative Committee.

(Draft) (February 2012, Road Department, Tohoku
Regional Development Bureau; Bridge and Structures
Division, National Institute for Land and InfrastructureManagement) was compiled and sent to all Regional
Development Bureaus for reference.

Damage Rate

Bridge Damage by Seismic Intensity
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%

260

Not Damaged
Damaged
39

9

113

20

188
60
9

86

421
165
30
2
3

19
4

5-lower 5-upper 6-lower 6-upper

7

JMA Seismic Intensity Scale

Figure 3.3.6.2 Example of the Outcomes of Analysisof the Results of Emergency Checks(3) Outline of the Investigative Committee on the
Repair of Bridges Damaged by the Great East Japan
Earthquake
The Investigative Committee on the Repair ofBridgesDamaged

by

the

Great

East

Japan

Earthquake was established under the auspices of theRoad Department, Tohoku Regional Development
Bureau, as a forum for deliberations concerning
methods of repairing road bridges damaged by theGreat East Japan Earthquake and points to bear inmind in doing so, as well as the potential for using theresidual structures from bridges washed away by the198Table 3.3.6.2 Outline of the Investigative Committee on the Repair of Bridges Damaged by the Great East
Japan Earthquake
Category
Objectives

Affairs Under
the Jurisdictionof theCommittee

MemberContent
An Investigative Committee shall be established to consider methods of repairing road bridges damaged by the Great
East Japan Earthquake on March 11, 2011, from the perspective of extending the lives of these bridges, and points to bear inmind in doing so; in addition, the objective of its establishment is to conduct deliberations regarding the potential for using theresidual structures from bridges washed away by the tsunami, and to contribute to technical advice required when
conducting permanent bridge repairs in due course.
The Investigative Committee shall provide guidance and advice concerning the following matters.
(1) Matters pertaining to methods of repairing major damage to road bridges affected by the disaster, from the perspective ofextending the lives of these bridges, and points to bear in mind in doing so.
(2) Matters pertaining to the potential for using the residual structures from bridges washed away by the tsunami, namely the
Numata Overpass, Kesen Bridge, Koizumi Bridge, and Utatsu Bridge.
(3) Matters pertaining to approaches to bridge management, taking into account the lessons learned from the Great East
Japan Earthquake.
Affiliation/Position
Name
Head, Bridge and Structures Division, Road Department, NILIM
Takashi Tamakoshi
Senior Researcher, CAESAR, PWRI
Shoichi Nakatani
Senior Researcher, CAESAR, PWRI
Jun-ichi Hoshikuma
Senior Researcher, CAESAR, PWRI
Yoshitomi Kimura
Senior Researcher, CAESAR, PWRI
Masahiro Ishida
Executive Officer for Road Information Management, Road Department, Tohoku Regional Tomoyoshi ItoNote 1)
Development Bureau
Shoichi AkagawaNote 2)
Executive Officer for Road Maintenance Planning, Road Department, Tohoku Regional Shoichi AkagawaNote 1)
Development Bureau
Kazuo SasakiNote 2)
Director, Road Works Division, Road Department, Tohoku Regional Development Bureau
Yoshikatsu Shibata
Director, Road Management Division, Road Department, Tohoku Regional Development Shigeru Kiga
BureauDeputy Director, Sanriku National Highway Office, Tohoku Regional Development Bureau
Shigenori Kumagai
Deputy Director, Sendai River and National Highway Office, Tohoku Regional Development Eiji Okuyama
BureauDeputy Director, Tohoku Engineering Office, Tohoku Regional Development Bureau
Kazunori SatoNote 1)
Hiroyasu NagaiNote 2)

Note 1) 1st Meeting
Note 2) 2nd Meeting onwards
Table 3.3.6.3 Meetings of the Investigative Committee on the Repair of Bridges Damaged by the Great
East Japan Earthquake
Date

Committee
1st Meeting

Matters Considered
・The objectives and rules of the Investigative Committee on the Repair of Bridges Damagedby the Great East Japan Earthquake
・Reports on the extent of the damage to bridges resulting from the Great East Japan
Earthquake
・Reports on the extent of the damage to bridges washed away by the tsunami

August 10

2nd Meeting

・Reports on the extent of the damage to bridges resulting from the Great East Japan
Earthquake
・Technical issues in the field in relation to the repair of damaged bridges
・Reports on the extent of the damage to bridges washed away by the tsunami

September 29

3rd Meeting

・Technical issues in the field in relation to the repair of damaged bridges
・Common issues to bear in mind in design and inspection
・A unified approach to the design of repairs
・Key diagnostic points in relation to damaged bridges and examples of responses
・Reports on the extent of the damage to bridges resulting from the Great East Japan
Earthquake
・Reports on the extent of the damage to bridges washed away by the tsunami

2011
June 29199

(4) Deliberations Aimed at Standardization

design method were also underway. It was amid this(i) Technical Standards for Road Bridges andsituation that the Great East Japan Earthquake

Elevated Roads (Specifications for Highway Bridges)

occurred, with immense damage being caused to

The Bridges Committee of the Japan Road

social capital as a result of a massive tsunami that

Association discusses the original drafts for revisions

struck coastal areas; there was serious damage toproposed by the Bridge and Structures Division, theroad bridges, with the superstructures of many being

Earthquake Disaster Prevention Division, and thewashed away, causing disruption to the road network.

PWRI in relation to the Technical Standards for

In light of this situation, it was decided to prioritize

Bridges and Elevated Roads (Circular Notice from thedeliberations aimed at revising the Specifications for

Director-General, City Bureau and Director-General,

Highway Bridges as soon as possible, in order toRoad Bureau, MLIT; hereinafter referred to asenable the outcomes of various surveys and research"Specifications for Highway Bridges"), which detail theconsidered since the last revision, as well as

technical standards for road bridges.

knowledge acquired from damage resulting from

As of March 11, 2011, when the Great East Japan

recent disasters, including the Great East Japan

Earthquake, deliberations were underway, focused on

Earthquake, to be reflected in the repair of existingreflecting

road bridges and the construction of new ones,

in

the

standards

newfindings

andresponses to various issues that had been built up

Table 3.3.6.4 shows the progress of deliberations.

since the 2001 revision; in addition, full-scale

The original draft revision of the Specifications fordeliberations aimed at transitioning to a partial factor

Highway Bridges was discussed at the 81st Meeting

Table 3.3.6.4 Progress of Deliberations by the Bridges Committee of the Japan Road Association
Date
2011
May 12

Committee
78th Meeting of the Bridges
Committee

July 27

79th Meeting of the Bridges
Committee

October 13

80th Meeting of the Bridges
Committee

December 14

81st Meeting of the Bridges
Committee

Matters Considered
・Issues and matters for consideration relating to the Specifications for Highway Bridges
in light of the Great East Japan Earthquake(1) Seismic motion(2) Design against liquefaction and fluidization(3) Design of components(4) Impact of tsunami(5) Seismic retrofit measures for existing bridges
・Issues and matters for consideration relating to the Specifications for Highway Bridges
in light of the Great East Japan Earthquake(1) Evaluation of the impact of seismic motion of long duration(2) Evaluation of the impact of seismic motion in excess of the design spectrum(3) Consideration of the necessity of revising the method of evaluating liquefaction(4) Analysis of cases involving rupture of the rubber bearing(5) Consideration of the performance that should be ensured in the event of tsunami
・Opinions and queries regarding the draft revision of the Specifications for Highway
Bridges・Responses in the draft revision of the Specifications for Highway Bridges in light of theGreat East Japan Earthquake(1) Matters to be considered in relation to tsunami(2) Draft revision of design ground motion(3) Appropriateness of the method of evaluating liquefaction(4) Revisions relating to clarification of the performance requirements for components(5) Responses to subsidence at the rear of abutments
・Opinions and queries regarding the draft revision of the Specifications for Highway
Bridges・Approval of the draft revision of the Specifications for Highway Bridges

200Table 3.3.6.5 Content of Main Revisions to the Specifications for Highway Bridges in Light of the Great East Japan Earthquake
SectionI. Common

Category
Maintainability

Consideration for tsunami in planning

Records

IV Substructure

Approach at the rear of abutments

Pier design

V Seismic Design

Matters to be considered in relation totsunamiRevision of Level 2 seismic motion (Type I)
Revision of regional correction factors
Matters pertaining to design around bearings

Matters pertaining to the design ofmountings for bearings and aseismaticconnectors

Content
In light of the fact that there were cases in which bridges employed structures that made itdifficult to ascertain the situation in the event of disaster, as well as cases in which it was notpossible to ascertain the situation promptly from a position close to the point of damage, thereliability of maintenance was added to the matters to be considered in relation to design.
A stipulation was added to the matters to be considered in relation to bridge planning, to theeffect that a bridge site and type should be selected that ensures consistency with the local disasterprevention plan and relevant road network plans.
As records concerning design and construction provide essential information for evaluating thesituation after an earthquake and conducting rational deliberations regarding repairs, a stipulation
was added, to the effect that such matters must be recorded appropriately and preserved in a waythat enables those records to be used in maintenance throughout the service life of the bridge.
In response to the pronounced differences in level that developed at the rear of abutments
following the Great East Japan Earthquake and other disasters, provisions were added concerning
the performance required in order to maintain the continuity of the road surface on the approach at
the rear of abutments, as well as points to bear in mind in relation to the design and construction
thereof.
In response to the reality of damage to the mountings of bearings and aseismatic connectors,
the provisions concerning verification of the load acting on bridges from bearings and aseismaticconnectors in the event of an earthquake were expanded.
A stipulation regarding local disaster prevention plans concerning tsunami was added to thematters to be considered in relation to the seismic design of bridges.
Verification and revision of seismic motion and regional correction factors in light of the impact of
the synchronization of hypocenters in a large-scale earthquake, as seen during the Great East
Japan Earthquake.
Clarification of the performance required of bearings, presentation of methods of verifying
performance, and rationalization of the structure around bearings, in light of examples of damagearound bearings resulting from the Great East Japan Earthquake.
As well as clearly stipulating the design to be used for mountings, due to the fact that cases
were identified in which the impact, such as damage to bearings, even extended to the mountingsof aseismatic connectors, a provision was added concerning the points at which aseismaticconnectors are to be installed.

of the Bridges Committee and the content approved;

The Japan Road Association publishes the Outline

following further deliberations within MLIT, a circularof Highway Earthworks and six Guidelines on

notice from the Director-General, City Bureau andHighway Earthworks, which are the equivalent of

Director-General, Road Bureau was published ontechnical standards concerning the structure of road

February 16, 2012, entitled Concerning Revisions ofearthworks. Of these, at the time of the Great East

the Technical Standards for Road Bridges andJapan Earthquake, deliberations were being carried

Elevated Roads. Following on from this, Specifications

out by the Road Earthworks Committee of the Japanfor Highway Bridges - With Annotated Commentary

Road Association, with a view to the revision of two of(Japana

the Guidelines on Highway Earthworks: Highway

commentary by the Bridges Committee on the

Road

Association),which

included

Earthworks: Guidelines on Retaining Walls andprovisions of the specifications for highway bridges in

Highway Earthworks: Guidelines on Measures to Dealthe circular notice, was published on March 26, 2012.

with Soft Ground. The Road Department and theTable 3.3.6.5 shows the main content of revisions

Research

Coordinatormade in light of the Great East Japan Earthquake.

Prevention

fromThis revised version does leave issues outstanding indeliberations as committee members.

relation to the transition to the partial factor design
method, so it adheres to a verification system basedon a performance specification system and allowablestress design using the same method employed in the2001 edition of Specifications for Highway Bridges.
(ii) Guidelines on Highway Earthworks

201

for

NILIM

Earthquake
participate

Disasterintheseguidelines were summarized and the content of theTable 3.3.6.6 Technical Standards Concerning

revisions considered (Table 3.3.6.9). The Committee

Road Earthworks
Outline

Guidelines

concluded from its deliberations that the existing

Outline of Highway Earthworks (FY2009 edition)
Highway
Earthworks:
Guidelines
on
Embankments (FY2010 edition)
Highway Earthworks: Guidelines on Cutting andSlope Stability (FY2009 edition)
Highway Earthworks: Guidelines on Retaining
Walls (FY2012 edition)
Highway Earthworks: Guidelines on Culverts(FY2009 edition)
Highway Earthworks: Guidelines on Measures to
Deal with Soft Ground (FY2012 edition)
Highway Earthworks: Guidelines on Temporary
Structures (March 1999)

editionissues in question.

of deliberations conducted after the Great East Japan
Earthquake. At the 1st Joint Meeting of the Road
Committee

and

the

Guidelineson

Highway Earthworks Investigative Subcommittee,
which was held in June 2011, the establishment of aDisaster Working Group and the policy on the
response by the Road Earthworks Committee werediscussed. Subsequently, during the second meetingof the Disaster Working Group, the results of the fieldsurvey conducted by the PWRI were discussed, in
relation to the factors contributing to the damage atnine locations where the damage was particularly
severe and the response to this in the guidelines. In
light of the outcomes of this discussion, draft revisions
to Highway Earthworks: Guidelines on Retaining
Walls and Highway Earthworks: Guidelines on
Measures to Deal with Soft Ground were discussed atthe 2nd Joint Meeting of the Road Earthworks
Committee

and

the

Guidelineson

Highway

Earthworks:

Guidelines

on

Embankments (FY2010 edition) already dealt with theTable 3.3.6.7 provides a summary of the progress

EarthworksofHighway

Earthworks Investigative Subcommittee, which washeld in January 2012; the content of the revisions wasapproved and they were published by the Japan Road
Association on July 30, 2012.
Table 3.3.6.8 shows the main content of revisions
made in light of the Great East Japan Earthquake. In
revising these standards, the factors contributing to
the damage were classified into Category I-IV, basedon the results of the survey of factors contributing to
the damage at nine locations where the damage wasparticularly severe; then, in relation to each of thecontributory factors, the deficiencies and excesses ofthe provisions and commentary in the existing202

Table 3.3.6.7 Progress of Deliberations by the Road Earthworks Committee of the Japan Road Association
Date
2011
October 27

November 11

Committee
1st Joint Meeting of the Road
Earthworks Committee and the
Guidelines on Highway Earthworks
Investigative Subcommittee
1st Meeting of the Disaster Working
Group

December 14

2nd Meeting of the Disaster Working
Group

2012
January 19

2nd Joint Meeting of the Road
Earthworks Committee and the
Guidelines on Highway Earthworks
Investigative Subcommittee

Matters Considered・Establishment of the Disaster Working Group・Policy on basic surveys of the damage
・Policy on the response by the Road Earthworks Committee
・Policy on the survey of factors contributing to the damage at locations where thedamage was severe
・Opinions and queries regarding responses in the Specifications for Highway Bridges
concerning the subsidence of approaches at the rear of abutments
・Opinions and queries regarding responses in the Specifications for Highway Bridges
concerning the subsidence of approaches at the rear of abutments
・Results of the survey of factors contributing to the damage
・Policy on responses in the Guidelines on Retaining Walls and Guidelines on Measures
to Deal with Soft Ground・Opinions and queries regarding responses in the Specifications for Highway Bridges
concerning the subsidence of approaches at the rear of abutments
・Draft revisions of the Guidelines on Retaining Walls
・Draft revisions of the Guidelines on Measures to Deal with Soft Ground

Table 3.3.6.8 Content of Main Revisions to the Guidelines on Highway Earthworks in Light of the Great East Japan Earthquake
Guideline
Highway
Earthworks:
Guidelines on Measures to
Deal with Soft Ground(FY2012 edition)
Highway
Earthworks:
Guidelines on Retaining Walls(FY2012 edition)

Content of Main Revisions
・A stipulation was added concerning liquefaction at points where there was pronounced subsidence ofembankments due to high groundwater levels and points where depressions in the original ground surface had
been filled.
・The description of construction methods that are effective in curbing deformation due to liquefaction wasenhanced.
・The provision regarding cases in which concrete foundations for base supports that have become tilted are being
replaced was enhanced.

Table 3.3.6.9 Policy on Responses in Light of the Results of the Survey of Factors Contributing to the Damage
Category
I

II

III

IV

Results of the Survey of Contributory Factors
The water level within the embankment was high at
points where runoff water from embankments and the roadsurface gathers due to catchment topography, and thegliding force at the time of the earthquake was greater than
the slip resistance, leading to the collapse of theembankment.
At embankments where the foot of the mound is besidethe edge of a body of water, such as a pond, even in cases
in which the foundation drainage layer reduced the waterlevel within the embankment, the water level reached theheight of the foundation subgrade or exceeded it, causing
the foundation subgrade to undergo liquefaction.
At depressions in the foundation subgrade, there wasliquefaction in the thick sand mat layer located below thegroundwater level, causing a major collapse.

The embankment was built in 1965 on sloping groundwith a low-density sand layer, and no particularconsideration was given to the design of embankments on
sloping ground or retaining walls in the guidelines at thattime. Consequently, subsidence has occurred in theembankment and cracks have appeared at the crest of theretaining wall, due to subsidence and slippage.

Policy on Response in the Guidelines
This issue has already been responded to in the Guidelines on Embankments(FY2010 edition), by strengthening the stipulation regarding drainage in relation
to the installation of a foundation drainage layer and horizontal drainage layers
on the berm.

The following response shall be adopted in the Guidelines on Measures to
Deal with Soft Ground (FY2012 edition).
・A warning shall be provided concerning places where there is a possibility ofliquefaction, such as in cases where the foundation subgrade is sandy soil
located adjacent to a body of water, such as a pond.
This issue has already been responded to in the Guidelines on Embankments(FY2010 edition), by stipulating the installation of a foundation drainage layer.
A stipulation shall be added to the Guidelines on Measures to Deal with SoftGround (FY2012 edition), concerning methods of dealing with places where
there is pronounced consolidation settlement and places where there is a large
depression or other significant unevenness in the foundation subgrade.
The Guidelines on Embankments (FY2010 edition) already contain aprovision regarding responses to unstable sloping ground.
The Guidelines on Retaining Walls (March 1999) already contain a provision
regarding consideration for the stability of retaining walls on sloping ground.
The Guidelines on Retaining Walls (FY2012 edition) shall contain a further
provision regarding cases in which concrete foundations for base supports thathave become tilted are being replaced.

203

(5) Collaboration with the Japan Society of Civil

Division at NILIM participated as members of the two

Engineers (JSCE)

committees shown in Table 3.3.6.10. At eachIn the immediate aftermath of the disaster, thecommittee meeting, the results of field surveys

JSCE established the Special Committee on the

conducted by NILIM were provided, along with

Great East Japan Earthquake, with the objective of

information based on the status of deliberations; inswiftly compiling the outcomes of surveys andaddition, at the committee's request, the Tohoku

research activities relating to the Great East Japan

Regional Development Bureau provided information

Earthquake; in addition, it established committees thatsuch as schematic drawings of road bridges managed

conducted activities focused on individual fields,by the Bureau.

including disaster phenomena such as tsunami andTable 3.3.6.10 shows the progress of activities by

Table 3.3.6.10 Progress of Activities by Committees Established by the Japan Society of Civil Engineers(i) Steel Structure Committee / Special Committee on Surveys of Steel Structures Following the Great East Japan Earthquake
Category
Purpose of
Establishment
Progress ofCommittee
Activities

Content
This committee was established to ascertain the extent of the damage to steel structures due to the Great East Japan Earthquake andanalyze the factors contributing to the damage based on field surveys and past survey reports, and to discuss matters and issues thatshould be reflected in the design, construction, and erection of steel structures, based on the results of these analyses.
Date
Committee
Matters Considered2011
1st Meeting
・Objectives of the Committee's activities, content of surveys, policy on surveys,
May 10etc.
May 31
2nd Meeting
・Policy on field surveys
・Report on the extent of the damage to road structures on expressways
October 5
3rd Meeting
・Report on the results of field surveys
・Policy on the compilation of the outcomes of surveys and deliberations
November 25

4th Meeting

・Compilation of the outcomes of surveys and deliberations

December 21

5th Meeting

・Compilation of the outcomes of surveys and deliberations

January 27

Presentation of Report・Extent of the Damage to Steel-frame Structures and the Analysis Thereof
Report of the Special Committee on Surveys of Steel Structures Following theGreat East Japan Earthquake(ii) Investigative Committee on Evaluation of Wave Force Inflicted on Bridges by Tsunami (as of October 2012)
Category
Purpose of
Establishment

Committee
Progress of
Activities

Content
This committee was established with the objective of clarifying the extent of damage to bridges damaged by the tsunami and conducting
deliberations regarding methods of evaluating the wave power acting on bridge structures as a result of tsunami, in order to incorporate
specific provisions regarding tsunami load in Standard Specification for Concrete Structures: Design, so that this knowledge can be utilized
in design in the future.
Date
Committee
Matters Considered2011
1st Full Committee Meeting
・Report on the extent of the damage to road bridges
August 8
November 4
2nd Full Committee Meeting
・Results of surveys of the damage to prestressed concrete bridges, etc.
・Development of a database of field survey results
・Tsunami simulations
2012
1st Joint Working Group・Assignment of topics relating to the status of deliberations by each member
February 2
February 14
3rd Full Committee Meeting
・Results of the analysis of the damage to bridges
・Introduction to the status of deliberations in the field of coastal engineering
May 18
4th Full Committee Meeting
・Results of the analysis of the damage to bridges
・Results of numerical calculations of tsunami wave power acting on bridge beams
June 26

Interim Briefing

・Introduction to the results of deliberations in each field

ground liquefaction, response measures relating to

the two committees. Both committees held briefings,

facilities and structures, and approaches to local

Committee (i) on January 27, 2012, and Committee

reconstruction plans and local disaster prevention(ii) on June 26, 2012, at which they presented theplans. Representatives of the Bridge and Structures

results of their deliberations.

204

References
1) MLIT Water and Disaster Management Bureau:
Outline of the Report on Damage to Public Works
Facilities Under the Jurisdiction of the Ministry ofLand, Infrastructure, Transport and Tourism
Resulting from Disasters in 2011
http://www.mlit.go.jp/river/toukei_chousa/bousai/saigai/kiroku/pdf/h23_houkoku.pdf
2) Cabinet Office: Concerning the Great East Japan
Earthquake
http://www.kantei.go.jp/saigai/pdf/201208281700ji
sin.pdf
3) Quick Report on Damage to Infrastructures by the2011 off the Pacific coast of Tohoku Earthquake,Technical Note of National Institute for Land andInfrastructure Management No.626; Technical
Note of Public Works Research Institute No.4202,
July 2011
http://www.nilim.go.jp/lab/bcg/siryou/tnn/tnn0646.
htm4) Japan Meteorological Agency website: Number ofAftershocks with a Magnitude of at Least 5.0
http://www.seisvol.kishou.go.jp/eq/2011_03_11_t
ohoku/aftershock/205

3.3.7 Ports and Harbors (including coastal
protection facilities in ports)

because most of the ports in Miyagi prefecture have

3.3.7.1 Port Facilities

Fukushima and Ibaraki prefectures, which may have(1) Damage Surveys

prevented strong amplification of the earthquakes.

thin sedimentary layers compared to the ports of

The National Institute for Land and Infrastructure

Damage to the wharves was in the form of bulging ofManagement dispatched damage survey teams ashead line towards the normal seaward side (Photoshown below, for investigating the damage caused to

3.3.7.2), as well as sloping of the walls and collapse of

port facilities. All of these surveys were done in

the rear apron (Photo 3.3.7.3), etc.

cooperation with the Port and Airport Research

There was remarkable damage to the wharves at

Institute. The damage surveys were divided into theSoma and Ibaraki ports, due to seismic movements.

Tsunami Team, that investigated the tsunami intrusion

Particularly at Soma Port, the wharf collapsed at many

situation and situation of damages caused by tsunami,

places. Apparently, first the seismic movements

and the Earthquake Team that investigated thecaused the wharf to bulge towards the sea side, andsituation of damages caused by earthquakes.

while the rear apron part was sunken, a rip current of
the tsunami caused a huge water level difference,(1) March 15-19, 2011 One person dispatched toleading to the washout (Photo 3.3.7.4). There are very

Ishinomaki Port and Sendai Shiogama Portfew examples of such extreme damage caused by the(Earthquake Team)compound action of seismic movements and tsunami.

(2) March 16-19, 2011 One person dispatched to
Kamaishi Port and Ofunato Port (Tsunami Team)(3) March 16-19, 2011 Two people dispatched toHachinohe Port and Kuji Port (Tsunami Team)(4) March 27-30, 2011 One person dispatched to
Kamaishi Port and Miyako Port (Tsunami Team)(5) April 5-8, 2011 Two people dispatched to Soma
Port and Onahama Port (Tsunami Team, Earthquake
Team)(6) April 5-6, 2011 One person dispatched to Kashima

Photo 3.3.7.1 Soma port breakwater devastation state

Port and Ibaraki Port (Tsunami Team)(7) April 12-14, 2011

One person dispatched to

Kashima Port and Ibaraki Port (Earthquake Team)
Damages to the port facilities were broadly classified
into damages to breakwaters caused by tsunami, anddamages to wharves caused by seismic movement.
Damages caused to breakwaters by tsunami between
Aomori and Fukushima prefectures was remarkable inports that recorded very huge tsunami waves. In someports such as Hachinohe Port, Kamaishi Port, andOfunato Port, there was displacement / overturning /collapse of breakwater caissons, and also massive
scouring due to flows (Photo 3.3.7.1)
Damage to the wharves was remarkable at the ports
in Fukushima and Ibaraki prefectures. There was very

Photo 3.3.7.2 Bulging of wharf head line at Ibaraki Port

little damage to wharves of northern Miyagi ports,(Hitachi Minato-ku)

206

3.3.7.1. The peak frequency of micro-tremor H/V
spectrum corresponds to the frequency greatly
amplified by the earthquake. If the peak frequency ofless than 2Hz can cause significant transformation of
the wharf, an earthquake can easily cause damage.
The peak recorded at Pier 3 was less than 2 Hz, while
it was more than 2 Hz at Pier Otsurugi, whichcorresponds well with the scale of the damage tothese sites.
Photo 3.3.7.3 Sunken wharf apron at Onahama PortAt Kashima Port, there was a huge contrast
between the damage caused to Berths A~B andberths C~D berths at Nankokyo Pier. As shown in
Photo 3-3.7.6, the paved surface around berths A~B
collapsed, while there was no damage to the adjoining
berths C~D. The micro-tremor H/V spectrum for bothsites is shown in Fig. 3.3.7.2. The peak of H/Vspectrum is not clear in berth D part, while theamplitude is not much above 1. This kind of
micro-tremor H/V spectrum in normal times ischaracteristic of very favorable ground conditions,Photo 3.3.7.4 Collapsed wharf at Soma Port

such as bedrock sites. On the other hand, themicro-tremor H/V spectrum in normal times of berth A(2) Disaster analysis

part showed a clear peak of approximately 1.5 Hz,

A feature of this earthquake damage was that thewhich corresponds to the huge damage.

breakwaters suffered extensive damage at the harbors
that reported high tsunami waves as mentioned above,
while the scale of damage to wharves in the sameharbor varied greatly depending on the district in somecases. This was thought to be because theamplification

characteristics(site

amplification

characteristics) in sedimentary layers from the seismic
basement up to the ground surface were different,
even at sites that were almost at the same distance
from

the

epicenter.

To

validate

thistheory,(a) Pier no. 3

micro-tremor recording was done at the sites during
normal times, including at Onahama, Soma, Kashima,and Ibaraki Ports, where wharves were damaged byseismic movements.
The results at Onahama Port and Kashima Port are
given below. At Onahama Port, Pier no. 3 sufferedextensive damage, while there was no damage to Pier
Otsurugi (Photo 3.3.7.5) The micro-tremors H/V
spectrum (ratio of horizontal and perpendicular(b) Otsurugi Pier

components of microtremor spectral amplitude during

Photos 3.3.7.5 Damage situation of wharf apron at

normal times) of both the sites are shown in Fig.

Onahama Port207

常 時 微動 H / V ス ペ クト ル
2

10
3 号埠頭

1

0.1

1

spectral ratio

spectra l ratio

10

10

1

frequency(Hz)spectra l ratio

10

0.1
0.5

2

1

1.5

2

2.5

3

frequency(Hz)
D部分
A部分

大剣埠頭

1

Figure 3.3.7.2 Kashima Port micro-tremor H/V
0.1

spectrum during normal times
110(3) Restoration measure response

frequency(Hz)As a restoration measure response, advise was
Figure 3.3.7.1 Onahama Port micro-tremor H/Vprovided in response to a request received from thespectrum during normal timessite at Onahama Port. Specifically, the caisson-type
wharf at Onahama port was inclined, so the angle ofinclination was checked and it was compared with awharf that had restricted service due to damage
caused by a previous earthquake. As for the base ofcargo handling crane, the crane base at the land side
could use a bearing pile, but the design documents
confirmed that some piles were not reaching up to thebase support, therefore, it was recommended to makea solid base in case of a need for urgent restoration. It
was also suggested to move the sea side base(a) Berth A

landward, as the transformation of wharf causes thecrane rail span to expand.
Moreover, it was decided to generate design
seismic movements at the port as time history
waveforms reflecting site amplification characteristics,
so new level 1 seismic movements were established
for ports for which the site amplitude characteristics
had not been properly evaluated, in order to contributeto the restoration design. Therefore, aftershocks wereobserved in several harbors, and the aftershock
records and site amplification characteristics were(b) Berth D

thoroughly evaluated and level 1 seismic movements

Photo 3.3.7.6 Damage situation of wharf apron atwere established. Fig. 3.3.7.3 shows an example ofKashima port

level 1 seismic movements at Pier No. 1 of Soma Port.

208

acceleration [gal]200

相馬港（1号埠頭）

100

absmax 164.7 [gal]

0
0

50

100

150

-100
-200

time [s]Figure 3.3.7.3 Soma Port level 1 seismic movements(4) Damage of tsunami-induced debris: cargocontainers and others(a) Damage of fence (North pier section of

NILIM dispatched 1 staff member to Hachinohe Port

Minato-district, Hitachinaka Port Area, Ibaraki Port,

on May 8-9, 2011, to conduct a disaster survey on thedrifted containers were removed)

driftage of ships, in coordination with staff of Port and(Crown height of walls T.P. + 2.20m, Observed

Airport Research Institute. They investigated damage

tsunami height T.P. + 4.32m)of the windbreak fence behind the slipway, which

Photo 3.3.7.7 Damage of tsunami-induced debris

suffered less than other fences around this area, as(cargo containers)

well as damage of the ships which drifted ashore inthis area.

(5) Restoration measures (council, study committee,

Moreover, NILIM dispatched 1 staff member on

etc.)

June 13, 2012 to the Hitachinaka Port Area of Ibaraki

Council and study committees established by thePort, for an interview survey of the tsunami evacuation,

Ministry of Land, Infrastructure, Transport and Tourism

and for a field investigation on the driftage of cargodeliberated restoration measures, using the data ofcontainers. These surveys helped in understanding

preceding disaster surveys and related analysis of thethe tsunami evacuation and the driftage of cargo

Great East Japan Earthquake and subsequentcontainers in terminal area. Details of the surveys are

Tsunami, provided by NILIM and the Port and Airport

1)

referred to in the exiting paper.

Research Institute.

(Summary of Surveys)

1) Disaster Prevention Group, Port and Harbor(1) May 8-9, 2011: 1 staff member dispatched to

Subcommittee, Transport Policy Council

conduct disaster surveys at Hachinohe PortThe Disaster Prevention Group, Port and Harbor(2) June 13, 2012: 1 staff member dispatched to

Subcommittee,

Transport

PolicyCouncilwas

conduct

established

May

2011

to

on

disastersurveysatMinato-district,on2,

report“Comprehensive Measures for Earthquake andHitachinaka, Ibaraki Port

Tsunami in Ports and Harbors” to the Minister. By June2012 the group had held 6 meetings, and on June 13,2012 it submitted the report on “Comprehensive
Measures for Earthquake and Tsunami in Ports and2)

Harbors”.

Prior to this report, in July 2011 the group urgently
publishedthe“Comprehensive

Measuresfor

Earthquake and Tsunami in Ports and Harbors (Interim3)

report),”including the principle of future tsunami

assumptions to develop the restoration measures for209ports and their hinterlands. The group investigated therestoration and reconstruction of damaged ports andfailure mechanism of port facilities, such as seawalls

hinterlands, future hazard assumptions required two

and breakwaters, for tsunami, and proposed newlevels of tsunami: frequently occurring tsunami andcomprehensive measures for tsunami, such as thelargest-possible tsunami. These assumptions required

restoration policy for damaged ports in cooperation

the measures to be based on the concepts of “disasterwith urban areas and industries in hinterlands. For theprevention” and “disaster reduction,” respectively.

Tsunami height (Simulation)

GPS wave gauge off Kamaishi
Tsunami height (Observed)

Inundation height isequivalent to athree-story building

Run-upheightCase without tsunami
breakwaters (Simulation)

Reduction of Tsunami Impact by Breakwaters at Bay Entrance (Case of Kamaishi Port)

Run-up height

Tidal level when thetsunami occurred
Water depth(Simulation)

Seawalls for tsunami(4.0m high)About 20km offshore

40% reduction

in tsunami height

Tsunami overflowed theseawalls 28 minutes
after earthquake

50% reduction
in run-up height(Simulation)

Case with tsunami breakwaters(Observed at theGreat East Japan Earthquake)

Run-up height
GPS wave gauge off Kamaishi
Obstacle to tsunami
Tsunami height (Observed)
propagation(Simulation)

About 10.0m

Tsunami height (trace height)

Tidal level when thetsunami occurred

Seawalls for tsunami
Tsunamibreakwater

Run-up height(4.0m high)

Tsunami overflowed theseawalls 34 minutes
Overflow of tsunami
after earthquakeat the seawalls(Observed by local office, MLIT)

delayed 6 minutes

Tsunami breakwaters at Kamaishi bay entrance would reduce the tsunami energy by 70-80%, while
there were concerns for overflows or diffractions around the breakwaters.
Note: Translated tentatively to English by the author based on materials from the Transport Policy Council

Figure 3.3.7.4 Reduction of tsunami impact by breakwaters at bay entrance (case of Kamaishi port)(Material of the 5th Disaster Prevention Group Meeting, Port and Harbor Subcommittee, Transport Policy
Council)5)

A tsunami breakwater was installed at the bay

gaining time for evacuation of residents. Wave

entrance to reduce the water level rise due toforce of tsunami was also decreased with decreasetsunami in inner area, and to prevent injury toof the current velocity. A tsunami breakwater

human life and property in inner area from tsunami,

should have a resilient structure, because it will beusing revetments, embankments, etc. Fig. 3.3.7.4

difficult to repair it quickly if destroyed, it will reduceshows

the reduction of tsunami impact by

the impact of subsequent tsunami, and it will

breakwater at bay entrance at Kamaishi Port, using

maintain calmness in ports temporarily until thethe hindcast analysis by the Port and Airport

restoration will be completed.

Research Institute.

4), 5)

Propagation of tsunami to

Therefore, NILIM provided various information

seawalls was delayed, because the current

on effects of tsunami breakwaters, and on damage

velocity was decreased with decrease of the wave

and failure mechanisms of seawalls in ports shownheight by tsunami breakwater. It was effective inin Fig. 3.3.7.5,

210

6)

in association with the Port andAirport

Research

Institute.

Moreover,

NILIM

Earthquake and Tsunami in Ports andsuggested the concept of resilient structures to

Harbors (May 2, 2011)

reduce the damage for largest class tsunami, after(Process of deliberation)

specifying the objective of disaster reduction and

May 16, 2011: 1st Disaster Prevention Groupdisaster prevention against the corresponding

Meeting•assumed tsunami, in accordance with the scale
and frequency of occurrence, as shown in Fig.
3.3.7.6.

Analysis of the characteristics of thistsunami, damage of tsunami prevention

7)

facilities

Based on this, the group prepared a report oninports,

andtheir

failuremechanisms

basic concepts of comprehensive measures inJune 3, 2011: 2nd Disaster Prevention Groupports for earthquakes and tsunamis. The report

Meeting•

indicated the following 5 viewpoints on restoration

Assumption of 2 levels of comprehensive

measures in ports for the Great East Japanmeasures for tsunami (disaster prevention

Earthquake and Tsunami: (1) Necessity to specify

and disaster reduction)•

the objectives for disaster prevention and disaster

Deliberation on “Comprehensive Measures

reduction respectively, and to develop evacuation

for Earthquake and Tsunami in Ports andmeasures, (2) Clarification of tsunami disaster

Harbors (interim report (draft))”reduction effects of breakwaters, (3) Necessity to

July 6, 2011: 3rd Disaster Prevention Group

ensure earthquake and tsunami resistance for

Meeting•logistics that support the regional economy, (4)Conclusion on “Comprehensive Measures

Necessity to respond sequentially over time, fromfor Earthquake and Tsunami in Ports andinitial response until restoration, and (5) Necessity

Harbors (interim report)”July

to build a strong logistics network for disasters.
Accordingly, the group reported basic concepts

6,

2011

Reporton“Comprehensive

Measures for Earthquake and Tsunami inPorts and Harbors (interim report)”

to specify the objectives for disaster prevention
and disaster reduction, through the specification of

February 29, 2012

the corresponding assumed tsunami in accordanceGroup Meeting•with the scale and frequency of occurrence of

Pickingup

4th Disaster Prevention
thepointstodiscuss

tsunami, as well as through the review of“Comprehensive Measures for Earthquake

management and operation systems for floodgates

and Tsunami in Ports and Harbors”

and land locks. Regarding the basic concepts, theMay 8, 2012: 5th Disaster Prevention Group

group proposedthefollowing measures for

Meeting•

earthquake and tsunami in ports, in accordance

Deliberation on “Comprehensive Measureswith the objective of disaster prevention/reduction:

for Earthquake and Tsunami in Ports andprotection of hinterland with seawalls, evacuation

Harbors (draft)”measures in port, strong and multiple information

June 13, 2012: 6th Disaster Prevention Groupsystems for evacuation: management system

Meeting•

based on safety first: as well as automation andConclusion on “Comprehensive Measures

remote operations to manage/operate floodgate

for Earthquake and Tsunami in Ports andand land lock.

Harbors (report)”
June 13, 2012 Reporton“Comprehensive<Reference: Disaster Prevention Group, Port and

Measures for Earthquake and Tsunami in

Harbor Subcommittee, Transport Policy Council>

Ports and Harbors (report)” to the Minister(Request for advice to the council)
No.

130:

Comprehensive

Measuresfor(Members of Disaster Prevention Group (as of211

June 13, 2012))

of Engineering, Gunma University◎Katsuhiko KURODA, Professor Emeritus, Kobe

Hitoshi IEDA, Professor, Graduate School of the
University of Tokyo

University○Masahiko ISOBE, Professor, Graduate School of

Kiyoshi KOBAYASHI, Dean, Graduate School of

the University of Tokyo
Fumihiko

IMAMURA,Professor,

Management, Kyoto University
Graduate

Kenji TAWA, Petroleum Association of Japan

School of Tohoku University

Makoto TOYOMA, The Federation of Electric

Masakazu UCHINO, The Mainichi Newspapers

Power Companies of Japan

Kunio OTOSHI, Professor, Kochi University

Motoya HAYATA, Japan Feed Trade Association

Takeshi

Norio

OKI,

The

Japan

Iron

and

Steel

Federation

MAKI,

Associate

Professor,

Kyoto

University ◎: Chairman, ○: Acting Chairman

Toshitaka KATADA, Professor, Graduate School

Failure Mechanisms of Seawalls

Scouring due toupward waves

Scouring (or collapse) due to upward waves

Collapse due toscouring caused
by upward waves

Scouring bybackrush

Scouring due to backrush

Collapse

Note: Translated tentatively to English by the author based on materials from the Transport Policy Council

Figure 3.3.7.5 Failure mechanism of seawalls (Material of the 3rd Disaster Prevention Group Meeting,
Port and Harbor Subcommittee, Transport Policy Council)

212

6)

Clarification of Disaster Prevention and Mitigation○ It is necessary to develop measures while clarifying the protection goals in accordance with the scale orfrequency of occurrence, and 2 levels of tsunami are simulated basically.
Tsunami with higher occurrence frequency

Largest class tsunami

Largest scale tsunami that occurs once in several or more decades

Largest scale tsunami that occurs once in several hundred to 1,000 years

Disaster prevention goal

Disaster mitigation goal
Protect human life

Protect properties
Maintain important port logistics
functions even just after the disaster[Land use]
Plan to protect major port facilities

At 3 major bays, deliberate
to ensure protection
standard against largest
class tsunami considering
cost performance.

Reduce economic losses
Restore promptly important port
logistics functions after the disaster[Land use]
Plan on the assumption that inner
levee area is inudated[Evacuation plan]
Plan assuming the worst case

Tsunami withhigheroccurrence
frequency

Largest classtsunami[Disaster prevention facilities]
Allow inundation of inner levee area, but plan to reduce damage bybreakwaters, etc. and utilize multiple protection system as required.

[Disaster prevention facilities]
Plan to prevent the inundation of inner
levee area

Note: Translated tentatively to English by the author based on materials from the Transport Policy Council

Figure 3.3.7.6 Developing countermeasures to prevent damage for frequently occurring tsunamis and to
reduce damage for largest class tsunamis (Material of the 6th Disaster Prevention Group Meeting,
Port and Harbor Subcommittee, Transport Policy Council)

7)2) Study committee on design Guidelines ofseawalls and breakwaters in port for tsunami

No protection facilities todisturb logistics efficiency

The study committee on design guidelines ofBreakwater

seawalls and breakwaters in port for tsunami had(Tsunami propagatesfrom the mouth ofbreakwaters)

held 3 meetings during December 2011 to March

Coastal protection
facilities

Port activity

Residence andindustry

2012, to prepare the draft guidelines. A seawall isdefined as a structure installed to protect thehinterland from damage due to tsunamis or storm
surges. There must be installed many kinds ofShoreline

Outer levee area

facilities facing the coastline in a port, so it isNote: Translated tentatively to English by the author based on materials from the Transport
Policy Council

difficult to install protection facilities for tsunami,

Figure 3.3.7.7 Concept of protection measures forsuch as revetments and embankments on atsunamis and storm surges in ports

coastline. Therefore, as shown in Fig. 3.3.7.7,
seawalls are commonly installed in ports. And

After the Great East Japan Earthquake andfunctioning with seawalls, an offshore breakwater

Tsunami, the Disaster Prevention Group, Port andis installed to reduce the water level in the port. It is

Harbor Subcommittee, Transport Policy Council

a general idea to protect life and properties on the

proposed that future hazard assumptions required

hinterland in a port.

two levels of tsunami: frequently occurring tsunami
213

and largest-possible tsunami. These assumptions

created if the ratio of wave height against waterrequired measures based on the concepts ofdepth will be low, or if the sea bottom slope will be“disaster prevention” to protect life and properties

relatively steep. Therefore, the exiting formula wason hinterland, and “disaster reduction” to at least

improved to adjust the increase of impact wave

protect life with comprehensive measures.

force due to undulating bore of tsunami.

knowledge

Moreover, it is also important to ensure theavailable for the designers of practical protection

stability of base mound of breakwaters for tsunami,

facilities to determine the details of design

because the stability of main body is damaged due

conditions and procedures for frequently occurring

to severe scouring of the base mound. Therefore,

tsunami, and to establish a concept for tsunami

hydraulic model experiments were carried out, toresilient

structures.

The

Centralinvestigate the failure mechanism due to thePrevention

Councilplannedto

However,

there

wasn’tenoughDisasterreviewthescouring of base mound, and countermeasures

assumptions of “Tokai, Tonankai and Nankaido

against scouring.

earthquakes,” and, in the future, the council might

To ensure the stability of base mound of

require introducing a performance design concept

breakwaters for tsunami, the study committee

for largest-possible tsunami to breakwaters, as

investigated the following 3 points: (1) Required

well as to high priority facilities such as seawalls, tomass of covering material for base mound to resist

protect hazardous materials. These issues also

the flow induced by tsunami at the bay entrance

faced a lack of knowledge for practical design.

(including head part of breakwaters), (2) Required

Therefore, the study committee would prepare

mass of covering material to resist the flow induced

the guidelines for designers to carry out practicalby tsunami along the breakwater, and (3) Required

design of breakwaters and seawalls in ports. The

mass of covering material for rear side of basestudy committee discussed the following 5 issues:

mounds to resist the overtopping flow through(1) Scope of guideline, (2) Basic concept ofbreakwaters induced by tsunami. The required

assumed earthquake and tsunami, (3) Basicmass of covering materials at each point wasconcept of required performance regarding theevaluated from velocity of the flow calculated in (1)objective of corresponding facilities, (4) Concept ofand (2), respectively. The existing equation

standardof

proposed by Isbash was applied, to calculate theperformance design simulation and its verification

designcondition,

examplesrequired mass of covering stones and blocks tostandards, and (5) Concept of tsunami resilient

resist the flow, introduced in the present technicalstructures.

standards and commentaries for port and harbor

The study committee improved the existing wave

facilities. This equation sometimes provides anforce formula regarding breakwaters for tsunami,

extremely

while considering overtopping and undulating

depending on the velocity of flow. In such a case,bores. Firstly, tsunamis are classified as to whether

the required mass of the covering material shouldthey

be evaluated through hydraulic model experiments,

formulateaundulating

bore

or

not.

Propagating the long wave of tsunami into shallow

overestimatedrequired

mass,

etc.

waters, the wave will divide into multiple waves

Regardingtheinvestigation

of

the

study

with short periods, and an undulating bore will becommittee, it is proceeding to prepare guidelines,

created in front of the tsunami. The impact wave

while

force due to bore has extremely large

performance,

values,reviewingtheconcept

reviewing

theofrequired

comprehensive

which can be clearly underestimated if using themeasures for tsunami in port reported by Transport

existing formula proposed by Tanimoto. In general,

Policy Council, investigating

the undulating bore will be created if the sea

tsunami resilient structures shown in Fig. 3.3.7.8,

bottom slope is very loose. The bore will not be

investigating

214

the

coefficient

the concept of
of

water

7)

level

difference to estimate wave force acting on

Shinji SATO, Professor, Graduate School of the

breakwaters for tsunami, as well as reviewing the

University of Tokyo

concept of performance design for seawalls and its

Susumu NAKANO, Professor, Research Center

procedures.

forManagement

Environment,<Reference: Study committee on design guidelines

of

The

DisasterandUniversityofTokushimaof seawalls and breakwaters in port for tsunami>

Tetsuya

HIRAISHI,

Professor,

Disaster(Investigation items)

Prevention Research Institute, Kyoto(1) Scope of the guideline

University(2) Basic concept of the assumed earthquake and(Members: Port and Airport Research Institute)tsunami(3) Basic

Shigeo TAKAHASHI, President
conceptofrequired

performance

Hiroyuki YAMAZAKI (Yoshiaki Kikuchi), Director

regarding to the objective of corresponding

for Special Researchfacilities

Yoshiaki

KURIYAMA,(4) Concept of standard design conditions, andDirectorforSpecial

DirectorforSpecialResearch

examples of performance design simulation

Takahiro

SUGANO,and its verification standards

Research(5) Concept of tsunami resilient structures

Ken-ichiro SHIMOSAKO, Director of Coastal and
Ocean(Progress of investigation)

Engineering

Field

/

Team

Leader of Maritime Structures GroupDec 12, 2011 1st meeting of study committee

Takashi TOMITA, Vice

• Direction to revise the technical standards andAsia-PacificDirector
Center

General,for

Coastalcommentaries for port and harbor facilities, Main

Disaster Research

items to be included in guidelines, Future(Members Concerned: MLIT)

schedule of investigation, etc.

Yasuo MATSUNAGA (Kazushige WATANABE),

Jan 31, 2012 2nd meeting of study committee

Director, Engineering Administration• Verification on the performance of breakwaters

Office, Engineering Planning Division,for tsunami, Report on the disaster reduction

Ports and Harbours Bureau

effect of breakwaters for tsunami, Tentative

Kazuhiro NAGAI (Hironobu ITO) Director forreport on the hydraulic model experiments andCoastal and Disaster Management,

future schedule, etc.

Coast Administration and DisasterMarch 9, 2012 3rd meeting of study committee

Reduction• Report on the progress of hydraulic model

Division,

Ports

and

Harbours Bureau

experiments, Investigation of the draft guideline.

Tomoyuki

TANAKA
Director(Hironobu

forTechnical

ISHIBASHI),
Standards,(Members)

Engineering(Member: Universities)

Engineering Planning Division, Ports◎Masahiko ISOBE, Professor, Graduate School of

Kazuhiro HIGASHIYAMA (Masakatsu SATO),

Susumu IAI, Professor, Disaster Prevention

Director,

Research Institute, Kyoto University
IMAMURA,Professor,

KIYOMIYA,

Professor,

SendaiResearchandEngineering Office for Port and Airport,

Graduate

Tohoku Regional Bureau

School of Tohoku University
Osamu

Office,and Harbours Bureau

the University of Tokyo

Fumihiko

Administration

Haruo
WasedaYONEYAMA,

Director,

Yokohama

Research and Engineering Office for

University

Port and Airport, Kanto Regional
215

Bureau

Engineering Field / Team Leader ofShinichi URABE, Deputy Director General,

Soil Mechanics and Geo-environment

NILIM

Group

Takeshi SUZUKI (Takashi KOIZUKA), Director,
Coastal,MarineandTaro ARIKAWA, Research Director (Coastal

Disaster

Structure Design)

Prevention Department, NILIM

Shinji SASSA, Team Leader of Soil Dynamics

Department Manager, ResearchGroup, Geotechnical Engineering Field

Takashi NAGAO, Director, Port and Harbor

Atsushi NOZU, Team Leader of Engineering

Department, NILIM
Takashi NEGI, Head,

Seismology

CoastalDisasterGroup,

Earthquake

Disaster Prevention Engineering Field

Prevention Division, Coastal, Marine

Eiji KOHAMA,Team Leader of Earthquake andand Disaster Prevention Department,

Structural

Dynamics

NILIM

Earthquake

Disaster

Masafumi MIYATA (Takashi NAGAO), Head, Port

Group,
Prevention

Engineering Field ◎ indicates Committee Chairman,

Facilities Division, Port and Harbor
Department, NILIM

names in parentheses ( ) are predecessors(Members Concerned: Port and Airport ResearchInstitute)
YoichiWATABE,

Director,

GeotechnicalConceptual Figure of Tsunami Resilient Structures○ The breakwaters, that would be difficult to restore quickly when collapsed, should have tsunami resilient structures to maintain the calmness in
ports in normal time and to deduce the damage in disaster.
○ Therefore, the technical standards for port and harbor facilities are amended based on the results from technical investigations including
hydraulic model experiments, and tsunami resilient structures for breakwater are examined considering the cost-effectiveness performance.

Disaster mechanism by the tsunami in this case

Breakwater with tsunami resilient structures

1) Caisson sliding was caused by the pressure of the water-level differenceon outer side of port produced by the overflow of tsunami ,and theoverflow caused scouring of the mound on the inner side of port.

[Outside the port][Inside the port]

Water-level difference

Overflow

External forceof tsunami[Inside the port][Outside the port]
CaissonFoundation mound[Foundation mound scouring]2) Flow was concentrated to the part where sliding was occurredcausing scour to be progressed on both sides of the mound.
Consequently, caissons remained on the mound were tilted too.

[Caisson tilting][Front view of breakwater]

Improvement as“tsunami resilient” structures

Caisson[Caisson sliding][Covering material]
As a Countermeasurefor foundation moundscouring

Foundation mound[Broadening and heightening of foundation mound]Control of caisson sliding[At tsunami attack]
Water-level difference

Overflow

CaissonExternal forceof tsunami

CaissonFoundation mound[Caisson sliding]

The resistance to a tsunami increases and the system will
not break even if the caisson moves.

[Foundation
mound scouring]

Note: Translated tentatively to English by the author based on materials from the Transport Policy Council

Figure 3.3.7.8 Example of tsunami resilient structures (Material of the 6th Disaster Prevention Group Meeting,
7)

Port and Harbor Subcommittee, Transport Policy Council )216

Acknowledgements

TATSUMI,In conducting disaster surveys, we received the

MakotoWASHIZAKI,

TakuyaIZUMIYAMA, Katsumi SEKI, Gyeong-Seonfull support of the Tohoku Regional Bureau andYEOM,

Masahiro

TAKENOBU,

Kanto Regional Bureau. In preparing the report,

KASHIMA,the members of the Disaster Prevention Group,

FUKUNAGA, Jyun-ichiro SAKUNAKA and Yuji

Port and Harbor Subcommittee, Transport Policy

WATANABE:

Council provided us their earnest and fruitful

East Japan Earthquake and Tsunami Disasteradvices during the deliberations. In preparing thein Ports and Coasts, Technical Note of PARI,

draft guidelines, the members of study committee

No. 1231, 200p., 2011 (in Japanese).

Masayuki

BANNO,

HiroakiYusukeUrgent Survey for 2011 Greaton design guidelines of seawalls and breakwaters

5) Transport Policy Council, MLIT: Material of thein port for tsunami provided us their earnest and5th Disaster Prevention Group Meeting, Port

fruitful advices during the discussions. We would

andlike to take this opportunity to express our deep

Japanese).

appreciation for their great assistance.

HarborSubcommittee,

2012

(in

6) Transport Policy Council, MLIT: Material of the
3rd Disaster Prevention Group Meeting, Port

References

and1) Kentaro KUMAGAI, Masaaki SAKURABA andHarborSubcommittee,

2011

(in

Japanese).

Hisanari USHIROOKA: Tsunami debris due to7) Transport Policy Council, MLIT: Material of thethe 2011 off the Pacific coast of Tohoku

6th Disaster Prevention Group Meeting, Port

Earthquake

andTsunami,

The

23rd

Ocean

Engineering Symposium, OES23-015, Japan

HarborSubcommittee,

2012

(in

Japanese).

Federation of Ocean Engineering Societies,
2012 (in Japanese).
2) Transport

Useful reference websites

PolicyMLIT:1) National Institute for Land and Infrastructure

Comprehensive Measures for Earthquake andManagement website: Information related to

Tsunami

the

in

Ports

Council,andHarbors(report):

Great

East

Japan

Earthquake

Disaster Prevention Group, Port and Harbor

Japanese)

Subcommittee, 2012 (in Japanese).

http://www.ysk.nilim.go.jp/oshirase/uc.html

3) Transport

PolicyCouncil,

MLIT:

(in

http://www.nilim.go.jp/lab/bbg/saigai/h23tohok

Comprehensive Measures for Earthquake andu/index.html

Tsunami in Ports and Harbors (Interim Report):

2) Ministry of Land, Infrastructure, Transport andDisaster Prevention Group, Port and Harbor

Tourism

Subcommittee, 2011 (in Japanese).

Disaster Prevention Group, Port and Harbor4) Shigeo
Yoshiaki

TAKAHASHI,KIKUCHI,

Kazuhiko
Takahiro

TODA,

website:Information

relatedto

Subcommittee, Transport Policy Council (inSUGANO,Japanese)

Yoshiaki KURIYAMA, Hiroyuki YAMAZAKI,

http://www.mlit.go.jp/policy/shingikai/s303_ko

Takashi NAGAO, Ken-ichiro SHIMOSAKO,

uwanbousai01.html

Takashi NEGI, Jinkatsu SUGENO, Takashi
TOMITA,

Hiroyasu

NAKAGAWA,

KAWAI,

Atsushi

NOZU,

Yasuhiro
Osamu

OKAMOTO,

KojiroSUZUKI,

Yoshiyuki

MORIKAWA,

Taro

ARIKAWA,

Mitsuyasu

IWANAMI, Taka-aki MIZUTANI, Eiji KOHAMA,
Toru YAMAJI, Kentaro KUMAGAI, Daisuke217

3.3.7.2 Coastal protection facilities in ports(1) Damage survey, on-site response
1) Activities of TEC-FORCE(1) March 16-19, 2011 1 staff member dispatched
to conduct disaster surveys at Kamaishi Port and1)

Ofunato PortThe disaster surveys described in 3.3.7.1 (1)(2) March 16-19, 2011 2 staff members dispatched

include the surveys on coastal protection facilities

to conduct disaster surveys at Hachinohe Port andin ports, as well as on port facilities. The Coastal,

Kuji Port

Marine and Disaster Prevention Department and(3) March 27-30, 2011 1 staff member dispatchedtheto conduct disaster surveys at Kamaishi Port and

Port

and

Harbor

Department,

NILIM,

dispatched 8 staff members for 7 series of surveys

Miyako Portduring March 16-30 (including 4 staff members for(Release of Prompt Report)

3 series of surveys, from the Coastal, Marine and(1) March 24, 2011

Disaster Prevention Department), to investigate

Kamaishi Port and Ofunato Port

the tsunami traces and the damages to the coastal(2) March 24, 2011protection facilities in ports, as well as to the port

Hachinohe Port and Kuji Port

facilities. All the investigations were carried out in(3)

cooperation with staff of the Port and Airport

Kamaishi Port and Miyako Port

March 31, 2011

Damages for Tsunami at
Damages for Tsunami at
Damages for Tsunami at

Research Institute.
2) Damages of coastal protection facilities

2)

The Coastal, Marine and Disaster Prevention
Department dispatched 6 staff members for 3
series of surveys during June 16 to September 1.
They conducted disaster surveys on coastal
protection facilities, to investigate the damage offacilities, and to understand the causes of failures.
The details of disaster surveys were included in the2)technical notes of NILIM.
The seawall type of coastal protection facilities
are more commonly installed in port areas andfishing(a) Collapsed seawalls in Ichikawa district,port

revetments.

areas,

comparedtoleveesorThus, the field survey on coastal

Hachinohe Port

protection facilities was focused on the seawalls in(Crown height of walls T.P. + 5.4m, Observed

port areas, to investigate the details of damages,

tsunami inundation height T.P. + 8.38m)

and to understand the causes of failures. Photo

Photo 3.3.7.8 View of disaster survey on coastal

3.3.7.9 shows some examples of tsunami damage

protection facilities

to coastal facilities.

Photo 3.3.7.8 shows a collapsed revetment in(Summary of Surveys)

Ichikawa district, Hachinohe Port. The details of(1) June 16-17, 2011 2 staff members dispatcheddisaster surveys were posted on the web site as a

to conduct disaster surveys on coastal protection

1)

prompt report, as well put into the report of urgent

facilities at Ofunato Port.

survey with Port and Airport Research Institute.

(2) July 19-20, 2011 2 staff members dispatched to
conduct disaster surveys on coastal protection(Summary of Surveys: Portions by the Coastal,facilities at Kesennuma Port

Marine and Disaster Prevention Department,(3) Aug 30-Sept 1, 2011

NILIM)

dispatched to conduct disaster surveys on coastal

218

2 staff members

protection facilities at Ogatsu Port, Onagawa Port,
Oginohama Port, Ishinomaki Port, and Matsushima
Port(Release of Prompt Reports)(1) June 27, 2011 Damages of coastal protection
facilities at Ofunato Port
(2) Aug 15, 2011 Damages of coastal protection
facilities at Kesennuma Port
(3) Oct 31, 2011 Damages of coastal protection
facilities

at

OgatsuPort,

Onagawa

Port,

Oginohama Port, Ishinomaki Port, and MatsushimaPort(b) Seawalls collapsed to seaside (Nagahama
district, coastal protection area in Ofunato Port)

These surveys revealed the damage of seawalls(Crown height of walls T.P. + 3.00m,

and revetments in coastal protection facilities at 20

Observed tsunami trace height T.P. + 10.02m)

areas in 7 ports along the coast of Iwate and Miyagi
prefectures.

(c) Scouring observed on seaside (Suga district,coastal protection area in Kamaishi port)(Crown height of walls T.P. + 4.00m,(a) Seawalls collapsed to landside (Chayamae

Observed tsunami trace height T.P. + 8.64m)

district, coastal protection area in Ofunato Port)

Photos 3.3.7.9 Tsunami damage to coastal(Crown height of walls T.P. + 3.40m, Observed

protection facilities

tsunami trace height T.P. + 8.07m)
As for the damage of seawalls, “collapse of mainbody” appeared with following failure patterns:
1-(1) development of cracks, 1-(2) damage due tocollision of driftage, and 1-(3) removal of top partfrom joint of main body. Extent of damage wasleast in (1) and largest in (3). “Scouring anddisplacement of main body” appeared with thefollowing failure patterns: 2-(1) slight scouring of
paved ground in front and behind the main body,2-(2) extensive wash away of ground due to219

current, 2-(3) collapse of main body due to wave
force and subsequent scouring, 2-(4) ground2) Study committee on measures for tsunami insubsidence of entire area, requiring embankment.

coastal area

“Dysfunctional operations” appeared with the

The study committee on measures for tsunami infollowing failure pattern: 3-(1) incomplete operation

coastal area held 4 meetings from April toof flap-board valve. Additionally, in a past disasterNovember 2011, and reported “Basic Concepts on

survey, the seawalls at Kuji Port showed 3-(2)Restoration of Coastal Facilities Damaged by theobstruction of passage through land lock.

2011 off the Pacific Coast of Tohoku Earthquakeand(2) Damage analysis and restoration measures

Tsunami”

4)inNovember

2011,

as

recommendations.

response

As mentioned in 1) above, seawalls are more

A council and study committee established bycommonly installed in ports, compared with

the Ministry of Land, Infrastructure, Transport andrevetments, embankments, etc. And functioning

Tourism deliberated restoration measures, usingwith seawalls, an offshore breakwater is installed

the data of preceding disaster surveys and related

to reduce the water level rise in the port. It is a

information on the Great East Japan Earthquake

general idea to protect life and properties onand subsequent Tsunami, provided by NILIM andhinterland in port. Therefore, NILIM organized thethe Port and Airport Research Institute.

damage of seawalls and related information, andrevealed the issues for their restoration. This

1) Disaster Prevention Group, Port and Harbor

information was reflected in the recommendation.

Subcommittee, Transport Policy Council

In

cooperation

with

other

bodies,NILIM

The Disaster Prevention Group, Port and Harbor

investigated the failure mechanisms for seawalls,

Subcommittee, Transport Policy Council wasand suggested the measures for their restoration.

established

on

May

2,

2011

to

report“Comprehensive Measures for Earthquake andAcknowledgments

Tsunami in Ports and Harbors” to the Minister. By

In conducting disaster surveys, we received theJune 2012 the group had held 6 meetings, and on

full support of the Tohoku Regional Bureau.

June 13, 2012 it submitted the report on

Especially, Mr. Norihiko NAGAO, deputy-director of“Comprehensive Measures for Earthquake andKamaishi Port Office, and Mr. Motokazu AYUKAI,

Tsunami in Ports and Harbors.” NILIM provided

assistant manager of the Port and Airport Division,various information to support the group meetings,

were kind enough to help us to conduct disasterin association with the Port and Airport Research

surveys on seawalls in the field. In preparing theInstitute.

report, the members of the Disaster Prevention

As shown in Fig. 3.3.1(5) 2), seawalls areGroup, Port and Harbor Subcommittee, Transportcommonly installed in ports. And functioning with

Policy Council provided us with their earnest andseawalls, an offshore breakwater is installed to

fruitful

reduce the water level rise in the port. It is apreparing the recommendation, the members ofgeneral idea to protect life and properties on

the study committee on measures for tsunami inhinterland in port. Coastal protection facilities incoastal provided us with their earnest and fruitful

ports are expected to have same function foradvices during the discussions. We would like todisaster prevention. Therefore, the outcomes fortakeseawalls should be applied to those for coastal

appreciation for their great assistance.

advicesthisduringopportunity

the

to

deliberations.

express

our

In

deep

protection facilities, such as failure mechanisms,
conceptoftsunamiresilient

structures

for

References

largest-possible tsunami, etc.

1) Shigeo

220

TAKAHASHI,

Kazuhiko

TODA,Yoshiaki

KIKUCHI,

Takahiro

SUGANO,

2) Ministry of Land, Infrastructure, Transport andYoshiaki KURIYAMA, Hiroyuki YAMAZAKI,

Tourism

Takashi NAGAO, Ken-ichiro SHIMOSAKO,

Disaster Prevention Group, Port and Harbor

Takashi NEGI, Jinkatsu SUGENO, Takashi

Subcommittee, Transport Policy Council (inTOMITA,

Yasuhiro

Japanese)

Osamu

http://www.mlit.go.jp/policy/shingikai/s303_ko

Hiroyasu

NAKAGAWA,

KAWAI,

AtsushiNOZU,

OKAMOTO,

KojiroSUZUKI,

Yoshiyuki

MORIKAWA,

Taro

ARIKAWA,

Mitsuyasu

uwanbousai01.html

IWANAMI, Taka-aki MIZUTANI, Eiji KOHAMA,
Toru YAMAJI, Kentaro KUMAGAI, Daisuke
TATSUMI,

MakotoWASHIZAKI,

TakuyaIZUMIYAMA, Katsumi SEKI, Gyeong-Seon
YEOM,

Masahiro

KASHIMA,TAKENOBU,

Masayuki

BANNO,

HiroakiYusukeFUKUNAGA, Jyun-ichiro SAKUNAKA and Yuji
WATANABE: Urgent Survey for 2011 Great
East Japan Earthquake and Tsunami Disasterin Ports and Coasts, Technical Note of PARI,
No. 1231, 200p, 2011 (in Japanese).
2) Kentaro KUMAGAI, Yuji WATANABE, Norihiko
NAGAO and Motokazu AYUKAI: Field Surveyof the 2011 off the Pacific coast of Tohoku
Earthquake and Tsunami on Shore Protection
Facilities in Ports, Technical Note of NILIM, No.
658, 39p., 2011 (in Japanese).
3) Transport

PolicyCouncil,

MLIT:

Comprehensive Measures for Earthquake andTsunami

in

Ports

and

Harbors(report),Disaster Prevention Group, Port and Harbor
Subcommittee, 2012 (in Japanese).
4) Study

Committee

Countermeasuresonon
Coastlines:

TsunamiBasic

Concepts of Restoration of Coastal Dikes etc.
Damaged by the 2011 off the Pacific Coast of
Tohoku Earthquake and Tsunami, 2011 (inJapanese).
Useful reference websites
1) National Institute for Land and InfrastructureManagement website: Information related to
the

Great

East

Japan

Earthquake

website:(inJapanese)
http://www.ysk.nilim.go.jp/oshirase/uc.html
http://www.nilim.go.jp/lab/bbg/saigai/h23tohok
u/index.html
221

Information

relatedto3.3.8 Airport

has already been exposed, the runway strip and the(1) Overview of Damage

area around Runway A are submerged. It is thought

During the Great East Japan Earthquake, tremorsthat it remained submerged for a long time because

measuring 6 on the Japanese seismic intensity scale

the area around Runway A is at a lower elevation thanwere observed in the cities of Natori and Iwamura,the other areas of the airport.

where Sendai Airport is located.

During the period March 21-27, NILIM, the Civil

Immediately after the earthquake, staff from theAviation Bureau and the Port and Airport Research

Sendai Airport Office began urgent inspection of theInstitute conducted a survey focused mainly on the

airport facilities. But a tsunami warning (6 m in height)

asphalt and concrete pavement of the runway,

was issued for the coastal areas of Miyagi Prefecture,

taxiway, apron, etc in order to check and assess theso the urgent inspection was halted and the staff

damage to the pavement, as well as identifying theevacuated to the office building. Subsequently, theareas that needed to be repaired before reopening of

forecast height of the tsunami was revised to "at least

the airport. Figure 3.3.8.1 shows the site plan of the

10m in height", and the tsunami actually arrived at

airport and the damage status. The following provides

Sendai Airport about 70 minutes after the earthquake.

details of the damage to the runway, taxiway, andPhotograph 3.3.8.1 shows the situation at the

apron.

airport at around 14:00 on March 12, the day after theearthquake. At this point, although the pavement
surface of Runway B, which is at a higher elevation,

RWY B
Parallel TWY
Apron
RWY A

Terminal Building

Photo 3.3.8.1 Situation at Sendai Airport around 14:00 on March 12, 2011
(photograph by the Geospatial Information Authority of Japan)

222

Road

R1

RWY B

Large Settlement
at Apron

Canal

R2

R4
RJ1
R3

R5

R6

R7

R8

T3 T4

Parallel TWY

R10

R11

R9
T5

T6 T7 T9 T10

T11

T8
T1

Apron

T2

Small
Settlement

Large
Settlement

Small
Settlement

Terminal
Building
RWY A

Crack
Figure 3.3.8.1 Status of Damage to Pavement(2) Damage to the Runway

there was a total of 11 cracks in the parallel taxiway,

Both of the runways at the airport are made ofas shown in Figure 3.3.8.1. Almost all of the cracks

asphalt pavement. However, Runway A was being

ran in a transverse direction across the whole width ofused as a temporary space for storing vehicles thatthe taxiway. The cracks were around 3mm at their

had been washed up at the airport as a result of thewidest, but no faulting was found at any of the cracks.

tsunami. Accordingly, a survey of Runway B was

As shown in Figure 3.3.8.2, localized settlement

carried out, with a view to reopening the airport.

due to liquefaction was found (i) at Taxiway C1, at the

As a result of visual inspection of Runway B, it waswesternmost point of the parallel taxiway; (ii) at theconfirmed that there was a total of 12 cracks, as

point where the underground road intersects with theshown in Figure 3.3.8.1. Almost all of the cracks ran inparallel taxiway (hereinafter referred to as the roada transverse direction across the whole width of theintersection); and (iii) at the point where therunway. The cracks were around 5mm at their widest

underground canal intersects with the parallel taxiway

and the faulting of the crack was also around 5mm at(hereinafter referred to as the canal intersection). The

most; no cracks were found that appeared likely tooccurrence of liquefaction at these points had been

impede the passage of aircraft. As a result of core

forecast even before the earthquake occurred, so soil

drilling at three points along the cracks, it wasstabilization was in the process of being carried out.

confirmed that in all of the cores, the crack penetrated

But localized settlement occurred at points where

the whole thickness of the asphalt concrete layer

stabilization had not yet been carried out at the time of(surface course, binder course, and asphalt stabilized

the earthquake.

base).

Photograph 3.3.8.2 shows the situation in regard to

The road and canal run underground north to south

localized settlement at the road intersection. At thisbelow the airport. With regard to the two points wherepoint, the settlement that occurred followed the edge

the road and canal intersect with Runway B,of the box culvert for the road. Although the shape ofliquefaction had been forecast even before thethe settlement was not measured, the width of theearthquake occurred, so soil stabilization had alreadysettlement was around 5m on both sides of the box

been carried out. Therefore, there were no areas

culvert, while the depth of the settlement was a few

where the evenness of the runway had deteriorated.

dozen centimeters at the shoulder of parallel taxiway.

(3) Damage to the Taxiway
As a result of visual inspection of the paralleltaxiway and other taxiways, it was confirmed that223

CanalRoad

Small
Settlement
at C1

Large
Settlement
atRoad Intersection

Small
Settlementat
Canal Intersection

Figure 3.3.8.2 Positions of Areas of Settlement due to Liquefaction on the Parallel Taxiway(a) Shoulder (forefront) and taxiway(b) Shoulder (left) and taxiway

Photo 3.3.8.2 Status of Localized Settlement at the Road Intersection(4) Damage to the Apron

stand #1, around the center line of aircraft stand #2,

The apron is made of jointed plain concreteand the middle of aircraft stand #3.

pavement. The designed bearing capacity factor of

The cracks in the apron were around 3mm at their3

the granular base is 70MN/m , while the thickness ofwidest, but no faulting was found at any of the cracks.

the concrete slabs is 42cm. The initial declivities of theMoreover, no faulting was found at the joints between

apron had been a gradient of 0.5% in the direction of

the concrete slabs. These cracks were concentrated

the terminal side and the Runway B side, with the joint

around the areas of localized settlement. So rather

between the 15th and 16th row of slabs in Figure

than having been caused by seismic motion, it was

3.3.8.3 forming the boundary.

thought that these cracks had occurred as a result of

As a result of visual inspection of the apron,

considerable localized settlement of the slabs due tonumerous cracks and settlement were found atliquefaction of the ground.

aircraft stands #1, #2, and #3 on the eastern side of
the apron. The positions of the cracks and the heightof the apron are shown in Figure 3.3.8.3. There wasconsiderable settlement on the eastern side of aircraft

224

GG
1

FF

EE

DD

CC

BB

ＡＡ

Ａ

Terminal Building Side (South)
B

C

D

E

F

G

H

I

J

K

L

2.200

O

2

2.300

3

3

2.250

4

N

1

2.150

2

M

4

2.350

5

5

2.400
6

6

7

7

2.450
8

8

2.500
9

9

2.550

10

12

Crack

10

2.400

2.600

11

標高 (m)
Elevation
(m)

11
12

2.650

13

13

Confirmed in March
14

2.700

14

Confirmed in May

15

15

16
17

2.050
2.100
2.150
2.200
2.250
2.300
2.350
2.400
2.450
2.500
2.550
2.600
2.650
2.700
2.750

16

Center of
Aircraft Stand #1

Center of
Aircraft Stand #2

2.700

Center of17
Aircraft Stand #3

Runway B Side (North)

The initialdeclivities of theapron had been a
gradient of 0.5%
in the direction ofnorth and south

Figure 3.3.8.3 Apron Cracks and Height (squares represent a single slab of concrete (7.5m×7.5m))(5) Repair Work・Stage 3

Table 3.3.8.1 provides a chronological summary of
the repair work carried out at the airport from theWith the goal of reopening the airport for civil

immediate aftermath of the earthquake. Repair work

aviation, areas that needed to be repaired before

was carried out over the following three stages, with areopening were considered with reference to theview to reopening the airport at the beginning of April.

results of the aforementioned survey and fallingweight deflectometer (FWD) tests. As a result, it was・Stage 1

decided that the parts of the apron with localized

Rubble clearance and other work was carried out,

settlement would remain closed for the time being; thewith the goal of opening 600m of the eastern side ofcracks on the runway and taxiway were repaired

Runway B and part of the apron for helicoptersusing sealing materials and the sections of pavementtransporting emergency supplies and conducting

on the parallel taxiway that had suffered localized

search and rescue operations. Usage of these areas

settlement were replaced. Following this, a limited

commenced on March 15, four days after thenumber of domestic flights began operating on April

earthquake occurred.

13, 33 days after the earthquake occurred.

・Stage 2

After reopening of the airport, repair work at aircraft

Rubble clearance and other work was carried out,

stand #3 was carried out in order to meet the deadline

with the goal of opening 1,500m of the eastern side offor the start date of international flights, which were

Runway B for aircraft transporting emergency supplies.

due to commence on July 25.

Usage of these areas commenced on March 16, fiveFirst, the concrete slabs were cut into cube-shapeddays after the earthquake occurred. Rubble clearance

chunks on the apron and lowered artificially in order toand other work continued thereafter and usage offill the void underneath the slabs. Next, an asphalt

3,000m of Runway B commenced on March 29, 18

mixture was paved over them. Usage of these areas

days after the earthquake occurred.

commenced on July 25.

225

Subsequently,

soilstabilization

andand full-scale repair work was completed by the end

concreteof FY2011.

pavement replacement work was carried out in regard
to the parts of the apron that had suffered settlement,

Table 3.3.8.1 Overview of Repair Work
Number of
Date

Days Since theSituation/Response

Earthquake
14:46 Earthquake occurs
14:47 Sendai Airport Office commences urgent inspection
March 110

14:49 Tsunami warning issued (6 m in height)
15:14 Tsunami warning updated (at least 10m in height)
15:59 Tsunami reaches Sendai Airport
07:30 Alert downgraded from tsunami warning to tsunami advisory

March 132

17:58 Tsunami advisory lifted
Checks of damage status commence

March 14

3

March 15

4

March 16

5

March 20

10

March 29

18

April 13

33

July 25136

September 25

198Work to remove soil, sand, and rubble commences
Interim use of Runway B (600m on the eastern side) commences(restricted to helicopters for search and rescue operations)Interim use of Runway B (1,500m on the eastern side) commences(restricted to aircraft transporting emergency supplies)
Drainage work by the River Bureau commences (some had alreadycommenced on March 13)
Interim use of Runway B (3,000m) commences (restricted to aircrafttransporting emergency supplies)
Sendai Airport reopens
Limited domestic flights begin operating
Regular domestic flights begin operating
Limited international flights begin operating
Regular International flights begin operating

Acknowledgments

Phenomena in the Event of Disaster, 2011 No.1,

In writing this report, we received various data from

August 17, 2011.

the Civil Aviation Bureau, the Sendai Airport Office,2) Tsubokawa, Y., Mizukami, J., Hata, I., Maekawa,the Tohoku Regional Development Bureau and theR.: Report on Damages of Pavement at Sendai

Sendai Port and Airport Technology Survey Office at

Airport due to 2011 Tohoku Region Pacific Coast

the Ministry of Land, Infrastructure, Transport andEarthquake, Technical Note of National InstituteTourism. We would like to express our profoundfor Land and Infrastructure Management, No.680,

gratitude to all concerned.

2012.

References
1) Japan Meteorological Agency: Earthquake andTsunami Warnings in the Event of Disaster: The
Great East Japan Earthquake, Report on Natural226

3.3.9 Building

A team of 49 persons from NILIM and 91 persons

3.3.9.1 Damages Survey, Field Support

from BRI was dispatched 43 times in all to the

The National Institute for Land and Infrastructuredamaged areas in Aomori, Iwate, Miyagi, Yamagata,

Management (NILIM) in conjunction with the Building

Fukushima, Ibaraki, Tochigi, Chiba, Tokyo andResearch Institute (BRI) was preparing to respond to

Kanagawa prefectures over a period of about 10

calls for help in regions damaged by the earthquake

months by January 27, 2012, to survey the damage

this time. It started its activities with the preliminary

from the earthquake, tsunami and fire, mainly toinvestigationplanbuildings, in response (about 2 weeks after thecountermeasures against future earthquakes or

earthquake) to the appeal of the Housing Bureau of theflooding from Tsunami on the basis of the current status

Ministry of Land, Infrastructure, Transport and Tourism.

of damage mainly to buildings and the “NILIM and BRI

The execution status of the damage survey is shown in

Joint Council to Study an Action Plan for Mitigation of

Table 3.3.9.1.

of

the

sites

in

order

to

Building Damage from Earthquakes” shall be held on
March 12 (Saturday) from 9 a.m.
Table 3.3.9.1 Status of Damage Survey
Period1
2

2011
March 12
March 14

3

March 14 - 16

4
5
6
7
8

March 14 - 15
March 15
March 16
March 23
March 24-26

9

March 24 -25

10March 24

11
12
13
14

March 25
March 30 -31
March 30 -31
March 30 -April 2

15
16
17

March 31
March 31-April 3
April 6 -9

18
19

April 6 -9
April 8 -10

20
21
22

April 11-12
April 12April 15-16

23

April 20-22

24

April 21-22

25
26
27
28

April 21
April 24-26
April 26 -28
April 27 -29

29

May 11 -14

Place
IbarakiNumber of persons
dispatched
NILM
BRI
1
1

Details

Requested by

Ibaraki

-

1

Iwate
Miyagi
Fukushima
Ibaraki
Ibaraki
IbarakiMiyagi
Fukushima
Fukushima
Tochigi
Ibaraki
Chiba
Ibaraki
Ibaraki
Ibaraki
Iwate
Miyagi
Chiba
Miyagi
Iwate
Iwate
Miyagi
Miyagi
Miyagi1

3

Investigation of damage to the Ibaraki Airport terminal building from caving of theceiling.
Investigation of the danger of prefectural houses (wooden houses) collapsingfrom liquefaction
Investigation of damage to wooden buildings from earthquake vibration

2
1
1
1
2

2
2
3
2
3

Investigation of damage to RC building s from earthquake vibration
Investigation of damage to general buildings from earthquake vibration
Investigation of damage to general buildings from earthquake vibration
Investigation of damage to wooden buildings from earthquake vibration
Investigation of damage to RC buildings from earthquake vibration

Housing Bureau
Housing Bureau
Housing Bureau
Housing Bureau
Housing Bureau

11

Investigation of damage to wooden buildings from earthquake vibration

Housing Bureau

1

2

Investigation of damage to building foundation from earthquake vibration

Housing Bureau

1
2

4
1
3
3

Investigation of damage to wooden buildings from earthquake vibration
Investigation of damage to steel buildings from earthquake vibration
Investigation of damage to steel buildings from earthquake vibration
Investigation of damage to general buildings from tsunami

Housing Bureau

1
1

1
-

Kanto Regional Office

1

4

3
-

3
1

1
2

2
2
1

Investigation of damage to general housing from liquefaction
Investigation of sites by the Ministry of Land, Infrastructure, Transport and Tourism
for understanding the status of devastation and urgent restoration
Investigation of damage to general buildings from tsunami.
Jointly conducted with the Port and Airport Research Institute.
Investigation of damage to wooden buildings from tsunami
Investigation of damage to buildings from fire induced by earthquakes. Jointly
conducted with the Tokyo University of Science.
Investigation of damage to steel buildings from ground shaking
Investigation of damage to steel buildings from ground shaking
Investigation of damage to building land from ground shaking

3-

Investigation of damage to buildings from fire caused by earthquakes

3

2

1
2
1

4
2
4

Investigation of damage to buildings conducted by the C Building construction
standard committee of NILIM
Investigation of damage to wooden buildings from ground shaking
Investigation of damage to buildings from fire caused by earthquakes
Investigation of damage to buildings from fire caused by earthquakes
Investigation of damage to wooden buildings from ground shaking

1

4

Investigation of damage to RC buildings from ground shaking

Ibaraki
IbarakiMiyagi
Fukushima
Miyagi
Iwate
Miyagi
Fukushima
IbarakiMiyagi
Aomori
Miyagi
Tochigi
Fukushima
IbarakiTochigi

227

Housing Bureau
Kanto Regional Bureau
Housing Bureau

30

May 24 -27

1

6Investigation of damage to wooden buildings from tsunami

2

3

Investigation of damage to steel buildings from ground shaking

June 27 -30

Iwate
Miyagi
Miyagi
Yamagata
Miyagi31

June 1 -2

32

-

2

33

June 30 -July 2

Iwate

1

1

34
35
36
37
38
39

June 30
July 1
July 4
July 6
July 8Aug 29 -30

Ibaraki
IbarakiTokyo
IbarakiMiyagi
Miyagi

1
2
1
2
1

2
2
1
2
1
-

40

Aug 31-Sep 1
Sep 22 -24
Oct 13-16
Nov 30Miyagi12

Miyagi
Miyagi
Kanagawa

1
1
2

2
5
1

Investigation of damage to general buildings from tsunami.
Joint investigation with ASCE.
Investigation of damage to general buildings from tsunami. Joint investigation withASCE.
Investigation of damage to steel buildings from ground shaking
Investigation of damage to steel buildings from ground shaking
Investigation of damage to steel buildings from ground shaking
Investigation of damage to steel buildings from ground shaking
Investigation of damage to steel buildings from ground shaking
Investigation of damage to fire-proof buildings from ground shaking. Jointly
conducted with the maintenance department of NILIM.
Investigation of damage to general buildings from ground shaking.
Jointly investigated with the American research team (members of UJNR) .
Investigation of damage to wooden buildings (public housing) from tsunami
Investigation of damage to wooden buildings from tsunami
Investigation of damage to steel buildings from ground shaking

41
42
43

Considering the status of damage seen, there was aseismograms caused by the destructive process in theneed to review the technical standards applicable toepicentral area of the main quake were extensively

safety measures. The “Building Structure Standards

observed. Large-amplitude records on the numerous

Committee” was therefore set up in April, whichlarge scale tremors which took place in succession

surveyed the sites to draft the technical standards forwere collected. The displacement response spectrum

building construction with the help of experts. The

on ground shakings recorded mainly at the devastatedcommittee studied the status of earthquake damage

areas was about as large as the earthquakes whichperceived in the initial stage and set up the tasks

occurred in the past. The long-period ground motion

related to damage caused by tsunami, liquefaction,

component of 4 seconds or more was not particularly

ceiling collapse, or falling escalators and the like in thelarge in the devastated areas and areas around Tokyo.

course of the project of updating the standards forRather the long-period component was predominant incollection and organization of the technical knowhow

several regions far-flung from the earthquake center

required to draft and revise the technical standards ofsuch as Saitama or Osaka, as shown in figure 3.3.9.1.

the nation, and carried out survey research with

Particularly in the skyscrapers in the bay area of

external help.

Osaka, continuous response of max approximately
130 cm amplitude was recorded on the top floor (52nd3.3.9.2 Damage to buildings from earthquakes

floor) for more than 10 minutes.

The committee first analyzed the records ofPseudo velocity response (cm/s)

observation of effects on buildings and ground forexample from ground shakings in the course of theinvestigation of damage to buildings from earthquakes.
It also conducted a detailed analysis of groundliquefaction and non-structural elements in addition todifferent type of structures of reinforced concretebuildings, steel buildings, wooden buildings andearthquake-proof buildings based on field investigation

HKD129 (Tomakomai)
OSK005 (Osaka Kunijima)
NIG010 (Niigata)
TKY016 (Tokyo Shinonome)
MIE003 (Yokkaichi)
OSKH02 (Osaka Konohana)
KNG002 (Yokohama)
SIT003 (Saitama Kuki)

5% damping, maximum horizontalof damage and its result. The summary is given below.
Period (s)(1) Ground shaking and response analysis

Figure 3.3.9.1 Pseudo velocity response spectrum of

The following characteristics were confirmed on

observations recorded in areas other than the affected
3.3.10-1

analysis of the observation records.

areas (K-Net and KiK-net

Several long-period and high level strong motion
228)

Strong motion accelerations were collected from theAdditionally, the results of the questionnaire survey

damaged (including wrecked) structures. The system

conducted on people using skyscrapers whose strong

verification method performed by using observed

motion observations were recorded to see how theyrecords confirmed variations in the 1st natural

would behave at the time of an earthquake and thefrequency before or after the main quake as shown in

effects

figuremeasures were organized.

3.3.9.2.

Seismometers

wereadditionallyofdamage,evacuation

andproactive

installed in buildings and surrounding ground after themain quake to confirm the behavior of each building(2) Reinforced concrete (RC structures) buildings

using aftershocks. The relative displacement at

The damage patterns on RC building structures was

expansion joints was calculated with the help of theseclassified and compared to the damage patterns

observation records to evaluate the natural frequency

induced by the 1995 Kobe Earthquake. As shown inor damping of buildings and study the input loss.

Table 3.3.9.2, the similar damage patterns were

Further, when the input earthquake motion on thesereported

between

Kobe

Earthquake

and

this

buildings (gyms) at the time of the main quake wasearthquake to the element level, while the damage

estimated from the aftershock observation result topatterns of the total frame decreases. . In fact, severe

investigate the damage from ceiling collapse, itdamage on the total frame was not observed inshowed that there is a response acceleration ofbuildings designed according to the current building

around 2G or greater on roof surfaces which serve ascode enforced in 1981. From the viewpoint of thethe bases for suspending the ceiling, this may betechnical standards, it indicates that major part of thesubstantial enough to make them rock violently.

typical damage patterns of the building observed inprevious earthquake was prevented by revision of the0.7

1st natural freq.[Hz]technical standards so far.
0.65

Table 3.3.9.2 Comparison of damage patterns of RC

0.6

buildings between in 1995 (Kobe Earthquake) and
0.55

2011 (Great East Japan Earthquake)
Damage observed from the 1995 Kobe
Existence ofEarthquake3.3.10-2), 3.3.10-3)
damage1995 2011
1) Shear failure of column
◎◎2) Compression failure at the concrete◎◎end section on column
3) Bending failure at the column top or
bottom (including damage by tensile◎―
or compression axial force)4) Axial failure on the longitudinal
reinforcing bar joint on columns5) Damage on anchorage of the 90°

hook hoops6) Bond failure on columns or beams◎
7) Shear failure of beams (including◎◎
beams with penetrating holes)
8) Shear failure of structural walls◎◎(including beams with openings)◎
9) Bending failure of structural walls
―10) Shear failure of beam-column joint11) Rupture of reinforcing bar on the gas◎◎pressure welded point
12) Damage to non-structural walls inapartment buildings
Note: If any relevant damage is observed, [○] is

0.5
0

50

100

150

200

250

300

350

400

Earthquake No.

(a) 1st natural frequency (■ is the main quake)
0.64

0.6

Damage at member level

1st natural freq.[Hz]0.62

Before 3/11

0.58

After 3/11
0.56
0.54
0.52
0.1

1

10

100

1000

Max accelaration at top floor[cm/sec2](b) Relation between response acceleration and 1stnatural frequency
Figure 3.3.9.2 Result of analysis of observation
records on steel buildings before and after the main
quake (21-story building in Tokyo)
229

entered in the “Damage existence” column, and
if no damage is observed, [-] is entered. If thedamage level was slight, △ is entered. If damage
is observed among buildings designed according
to the current building code, ◎ is entered.
A detailed survey and post-earthquake damage
observation was carried out on damaged 11 RC
buildings designed by the old building code before
1981. 4 buildings were categorized as severe damage,
4 as moderate damage, and 3 as minor damages.

Photo 3.3.9.2 Shear failure of non-structural wall

Some buildings show severe damage like shear failurein short columns (Photo 3.3.9.2) or shear failure in load

The analysis results confirmed that if structural slits

bearing walls. Although the damage to structural

were made in the spandrel or hanging walls of

elements was comparatively minor, the damage ofbuildings which suffered major damage from shear

non-structural wall such as shear failure in partition

failure in short columns, the building could achieves

walls (Photo 3.3.9.2), the damage of non-structural

the ductile behavior in a range of the response of theelements like inner/exterior cladding, and the danger ofstory drift with an equivalent single-degree-of-freedom

falling object accompanied by above nonstructural

system. It indicates if the seismic retrofitting including

elements damages made it difficult to use continuously.

improvement of the entire building strength is difficult inThis proved that it necessary not only to ensure theterms of the time, budget and life cycle cost, thesafety of the structure by retrofitting, but also to reduce

damage can be temporarily mitigated by making thethe damage of non-structural elements for sustainablestructural slit preceding to the strengthening when theuse of the existing buildings after the earthquake

adequate strength and ductility of the bare frame canbe confirmed.
On the other hand, with regard to damaged large
eccentric buildings, building models with additionalload carrying capacity in order to improve torsional
behavior was created and earthquake response
analysis was carried out. The result showed that there
was almost no improvement in its torsional behavior
from original model. It is generally recommended to try
improving eccentricity, rather than to increase thelateral load carrying capacity of buildings for large
eccentric buildings.

Photo 3.3.9.1 Shear failure of short column(3) Steel buildings
Detailed analyses of damage to steel buildings havebeen conducted on school gymnasiums similar tofactories or warehouses on the basis of the results ofthe field surveys in the devastated areas. Structure
types of school gymnasiums designed in accordancewith the old and current building codes were comparedandstudiedinadditiontoretrofitted

gymnasiums. The result is given below.
230

schoolThe

damagetothestructuresofschoolseismic diagnosis and seismic reinforcement include

gymnasiums designed by the old building codes (55those such as first finding out the seismic intensity

gymnasiums) was classified into 6 types. In theseacting on the roof surface from the horizontal

types, (1) Buckling or fracture of bracing elements andload-carrying capacity of the top story, and thenfracture of joints and (2) Buckling of diagonal

calculating the roof shear force depending on the roof

elements of lattice columns, were classified as majorarea ratio, or if an abbreviated calculation method isdamage, which were seen in 4 school gymnasiums

desired,( less than 10% damage rate). This damage rate wasmultiplying the weight that should be transferred fromsmaller than that of the gymnasiums built by the old

the roof surface by 0.55×Ai×Fes.

building codes damaged in the Mid Niigata Prefecture

methods like these can reduce the damage to thesecalculatingtherequired
10)

5)-7)

strengthby

Suitable designparts from earthquakes.

Earthquake in 2004 targeted in a similar survey(about 30% damage rate). Comparatively, unlike thegymnasiums built by the current building codes, thebraces or columns of these gymnasiums designed by
the old codes did not have sufficient structural strength,
and they did not have joints of load-carrying capacity,which were considered to be the main reasons ofdamage. In this survey of retrofitted gymnasiums
reinforced with braces, almost no damage wasobserved. Thus we can say that damage to buildings
can be mitigated by proper retrofitting.
On the other hand, damage types (1) and (2)mentioned above were not seen in gymnasiums built
Photo 3.3.9.3 Example of damage at RC column andby the current building codes (29 gymnasiums). They

Steel roof joints (bearing support parts)

suffered damage of other types, namely (3) Abrasion
or cracks in concrete at the joints (bearing support
parts) of RC columns and Steel roof frames, (4)Besides, damage of non-structural elements ofDeflection of roof horizontal braces, (5) Cracks ingymnasiums such as ceiling and lighting fall, exterior

column base concrete, and (6) Others (overturning ofwall collapse, interior wall collapse, and window glass

floor struts, etc.. However, the damage level of thesebreakage was observed. Damage of extensively fallen4)

as minor in almost all cases,

ceilings was observed in 4 gymnasiums. Damage of

except for 1 gymnasium which suffered moderateceiling break or fall was observed in relatively large

damage. Unlike the damage rate of gymnasiums

numbers in the gymnasiums designed by the current

designed by the old building codes, the damage levelbuilding codes. There was not much difference in theof buildings designed by the current building codes

tendency of ceiling damage in the gymnasiums

was determined as minor in most cases, and there

designed by the old and current building codes. The

was no major damage. Further it was seen that among

ratio of the gymnasiums with IIw or greater in thethe damage types described earlier, the rate of type (3)damage level classification of non-structural elements

Damage at the joints (bearing support parts) as shown

was relatively higher in the current building codes thanin Photo 3.3.9.3 was comparatively high. The types ofin the old ones.

types was determineddamage and their countermeasures are described in“Design

Recommendations

forComposite

8)

Constructions” of the Architectural Institute of Japanfor example. Also, the methods of designing RC
columns, gable walls and Steel roof joints used in
231

Is

Ｏｓ

II s

III s

IV s

developed by filling swamps or rice paddy fields, evenVs

if there is no ground deformity as seen near Kurihara(76)

Entire(45)

Old code(29)

Current code(2)

Retrofitting

and Osaki cities in Miyagi prefecture, Nasu town in
Tochigi prefecture and Hitachiota city, Naka city, Joso
city and Ryugasaki city in Ibaraki prefecture.
As part of the detailed survey of damage to woodenbuildings, structural specifications, layout of structural
0%

20%

40%

60%
Proportion

80%

elements was studied along with the damage status of100%

several buildings in areas where the damage was(a) Damage level classification of structural frames

comparatively greater. The relation between the wall
capacity (ratio of shear walls in the investigated

Ｏw

(76)

Entire(45)

Old code

Iw

II w

III w

buildings to required shear walls by building code) andIV w

residual deformation was also studied. As residual
deformations of investigated buildings were not large
in wooden buildings as shown in Figure 3.3.9.4(a) ,there was no definite trend between wall capacity(29) Current code(2)

and residual deformation. The result of the study on
Retrofitting

the relationship between the rate of eccentricity and
0%

20%

40%

60%
Proportion

80%

residual deformation was also the same. From the

100%

11)

result of a similar study

conducted after the Mid(b) Damage level classifications of non-structural

Niigata Prefecture Earthquake of 2004 shown inelements

Figure 3.3.9.4 (b), we can see that the tendency of

Figure 3.3.9.3 Damage level classification (numbers inresidual deformation is smaller when the wall capacity( ) on the far left indicate the number of gymnasiums

is greater. This is because of several factors such as
the different characteristics of ground motion related todamage to wooden buildings and the difference inseismic intensity. However the result cannot be(4) Wooden Buildings

affirmed, as few buildings were surveyed this time.

Several cases of damage to wooden buildings due
to ground ground motion were confirmed at Osaki city

0.3

in Miyagi prefecture, Sukagawa city in Fukushima

X (east-west) direction

Residual deformation (rad)prefecture, Nasu town in Tochigi prefecture, Hitachiota
and Naka city in Ibaraki prefecture. In Kurihara city in
Miyagi prefecture where the seismic intensity was 7,
the damage to wooden buildings was not severe,
unlike the past records of earthquakes of the same

Y (north-south) direction

0.2

0.1

seismic intensity. Damage due to ground deformities
other than the structural members was large in0

housing areas in cities like Sendai in Miyagi prefecture
and Yaita in Tochigi prefecture, and as a result the

0

0.5

1

1.5

Wall capacity

number of damaged buildings was also greater.
Further, damage of roof was greater in Fukushima and(a) 2011 Great East Japan Earthquake

Ibaraki, than in Miyagi prefecture where the number of(First floor only)

the past earthquakes damage is larger. Other than that,ground motion is likely to be greater in housing areas
232

Residual deformation (rad.)appeared to have performed well. Because theexpansion joints and covers did not follow the0.2

movement of isolation layers, some of them were
X direction on 1st story
Y direction on 1st story
X direction on 2nd story
Y direction on 2nd story

0.1

damaged (Photo 3.3.9.4). These damages wereconsidered as damage due to lack of estimation in thedesign.
Scratchboardswere

installedtomeasuredisplacement of the isolation layer during earthquakes.

0
0%

100%

200%

300% It was confirmed that there was a displacement ofWall capacity in the building codeabout 20 cm in most of the 8 SI buildings surveyed,
and the largest displacement was about 40cm.

(b) Mid Niigata Prefecture Earthquake of 2004

Among the seismic isolation devices (hereinafter to11)(seismic intensity 7)

as SI devices), lead dampers, cracks (Photo 3.3.9.5)

Figure 3.3.9.4 Relationship between wall capacity andappeared on their surfaces, and some of dampers

residual deformation

actually had to be replaced. As for steel dampers, theirsurface coating peeled off, and in some cases residual

In addition, the areas recorded strong ground motion

deformation was observed on the steel part. These

where the amount of damage to wooden buildings

deformities did appear in the series of earthquakes

1),12)(Respective NS and EW element of

which occurred during main shock on March 11 and its

JMA Furukawa-Mikkamachi, K-NET Furukawa, K-NET

aftershocks. In addition, rust and other such defects

Ishinomaki and K-NET Saitama) were used toalso appeared on the surface of junctions and othercalculate the earthquake response, with the wallparts in some of the SI devices.

was larger

capacity of each story as the parameter of structural

In some of the buildings affected by the tsunami, themodels of 2 story wooden houses.

isolation layer was submerged in the water. This does

The result showed that the response by the input of

not mean that the performance of the SI devices does

JMA Furukawa-Mikkamachi and K-NET Furukawa

not be kept. In this case, to check the performance ofincreased in case that the wall capacity was less thanSI devices, it is necessary to conduct of proper

1.0, and the maximum deformation angle did not

maintenance for assessing the durability of the SI

exceed 1/10rad, even when the wall capacity was

devices and its joints. A similar survey, which was

about 0.6. A comparison of this result to the damage

conducted on the SI buildings in Kanto region, showed

condition of wooden buildings observed in the detailed

the same results, though the response and damage

survey shows that the damage condition of Ishinomaki

level was less.

city in Miyagi prefecture and Naka and Hitachiota cities

Field surveys were carried out on 10 SI single family

in Ibaraki prefecture matches the analysis result to ahouses in Miyagi. The intensity of ground shaking

great extent, but the damage condition in Furukawa

measured around these SI houses was between 5.5city in Miyagi prefecture was smaller than the analysis(6 minus) to 6.2 (6 plus). There are no structural

result.

damages of these houses, showing that the isolation
layer had performed well.

(5)Seismically Isolated buildings
A field survey was conducted on 16 seismicallyisolated (hereinafter to as SI) buildings in Miyagi and 1
in Yamagata Prefecture (offices, medical institutes,etc.). There was little damage to building frames inevery building, and even during severe earthquakes
with intensity exceeding 6 minus, the seismic isolation
233

nearly circular in Miyagi, whereas the shape wasparticularly large in the east-western direction in
Fukushima. The largest displacement from the originof the isolation layer was 24.5 cm in buildings of
Fukushima. A good correlation was observed between
maximum displacement of the isolation layer andseismic index of JMA at nearest earthquake
observation records, as shown in figure 3.3.9.6. The
results of scratch boards were very useful to confirm
the response of the isolation layers, and to compare
Photo 3.3.9.4 Cover broken by contact etc.

the displacement locus to the analysis result.
1.2

Horizontal acceleration1
Largest acceleration ratio

Upper part of the seismic isolation layer
Upper part of building

0.8
0.6
0.4
0.2
0
0

200

400

600

800

Largest acceleration (lower part of the seismic isolation layer) (gal)Photo 3.3.9.5 Cracks in lead damper

Figure 3.3.9.5 Largest acceleration at the upper part ofHowever, the outer structural parts where theisolation layer and the top of the building vs. the lower

seismic isolation layer did not respond well got

part of isolation layer

damaged, as seen in the blocks in the outer foundation

30

flanks around the buildings from the tsunami or ground

Horizontal direction
Maximum displacement of isolation layers( cm)shaking, and damage on the floors around thegateways. The displacement records of the scratchboards around 5 buildings were confirmed, and the
direction of displacement was found in the south-east
direction

in

most

cases,

andthemaximum

displacement was about 10 cm to 35 cm.
The seismic behavior of SI buildings can beunderstood from seismic observation records and from

20

10

0
4

the result of scratch boards. Among the observed
accelerations below isolation layer, the largest one was14)

observed in a building of Fukushima Prefecture

5
6
Measured earthquake intensity(a) SI buildings

followed by Miyagi and Ibaraki prefectures, and lower
in Tokyo and Kanagawa prefectures. As shown in
Figure 3.3.9.5, as the maximum acceleration becomeslarger in lower part of the isolation layer, the maximum
accelerations at upper part of isolation layer tend to beless. The displacement locus of the isolation layer
calculated by using the acceleration records was234

7

motions in Tokyo bay area during the 2011 earthquake

40

Maximum displacement of isolation layers (cm)

is much longer than those at the liquefied zones during
the past earthquakes in Japan. Also was suggested

30

that the amplitude and predominant period ofacceleration time history change drastically due to soil

20

liquefaction in the area. As shown in Table 3.3.9.3, theNeq values estimated at Chiba port and Yumenoshima

10

sites for the 2011 earthquake were about 20 to 60,
which are about two times larger than those for the

0
5

5.5

6

1987 earthquake. For the both earthquakes, there

6.5

Measured earthquake intensity

were no liquefaction remarks on ground surface at the(b) SI houses

sites because the equivalent shear stress ratios might

Figure 3.3.9.6 Relation between measured

be lower than the soil liquefaction resistance.

earthquake intensity of earthquake motion, and

The Neq values estimated in Kobe port island during

maximum displacement at isolation layer

the 1995 earthquake could be, however, about 5-10 ,19)

which might be about 1/4-1/6 times smaller than thosein Tokyo bay area during the 2011 earthquake.

A questionnaire survey was conducted on residents
and users of both SI and non-SI buildings regarding

Based on the estimated results and discussions on

safety and habitability. The effect of seismic isolation in

their relationships with earthquake magnitude, it isreducing the shake was apparent which helped inconcluded that the Neq values could roughly be

alleviating the fear and discomfort of the residents andpredicted for a huge earthquake with magnitude M > 8users. And to the question on difficulty in performance,by extrapolation of the existing M-Neq relations for the

few people replied that “I cannot move.” A comparison

past earthquakes with magnitude M < 8, those wereof the status of furniture and other movables showedempirically proposed in the previous studies19)-21).

that the damage in the rooms was minimal from fallingof cupboards, rolling of furniture etc in SI houses and Table 3.3.9.3 Number of equivalent cyclic shear andin medical facilities etc., it was confirmed that there shear stress ratio for soil liquefaction during earthquakes
Chiba Port

Number of equivalent
cyclic shear
20-50

Shear stressratio
0.12-0.18

Yumenoshima30-60

0.10-0.15

Yumenoshima

10-30

0.05-0.08

Kobe Port
Island5-10

0.3-0.5

was no damage in the rooms and work resumed as

Earthquake

Site

usual immediately after the earthquake, because of2011 Great East
Japan Earthquake(MW=9.0)
1987 Chiba Toho-oki
Earthquake (Mj=6.7)
1995 Kobe
Earthquake (Mw=6.9)

the private generators and emergency feed water lines
installed for emergency use for lifelines.
(6) Liquefaction
One-dimensional effective stress analyses were
performed for the vertical array recordings of strong15)-17)ground motions

at Chiba port and Yumenoshimasites, to estimate the number of equivalent cyclic shear
for liquefaction, Neq, in the Tokyo bay area. The
correction factor to determine soil liquefaction
resistance with seismic magnitude employed in the
Recommendations for Design of Building Foundations
18)(Architectural Institute of Japan)

could be verified

from the relationship between the estimated Neq
values and earthquake magnitude.
It was revealed that the duration of strong ground235

Yumenoshima

Chiba Port

Yumenoshima

Kobe
Recommendations for
Design of Building
Foundations (AIJ)

Photo 3.3.9.7 Collapse of integrated ceiling
Figure 3.3.9.7 Relationship between earthquake

3.3.9.3 Damage to buildings by tsunami

magnitude and number of equivalent cyclic shear for(1) Background of field investigation and study

soil liquefaction

The NILIM and the BRI jointly created a tsunami
damage survey team consisting of 27 members, for(7) Nonstructural components

autonomous

investigation

of

sites

mainlytoMore damage was observed to the nonstructural

understand the actual status of damage by Tsunami tocomponents with the older construction method. Also,

grasp the whole damage of the Great Earthquake andthe damage type of breaking and falling was observed

also to gather information on the structural, locational,

to the nonstructural components installed in higher

functional and other such requirements of tsunami

places. As for ceilings, the damage tended to be

evacuation buildings during restoration. The First

greater with more severe structural damage, for

Tsunami Damage Survey Study Meeting was held on

example damage to the horizontal braces on the roof

March 17, 2011 and the field survey team was first on

or to the roof joints (supports) (Photos 3.3.9.6 andMarch 30, 2011, about three weeks after the outbreak

3.3.9.7).

of tsunami, and the NILIM and BRI conducted three

As for window glass at the gymnasiums, thesuch field surveys in all.

damage was greater at the building designed with theAfter that, “40. Study towards Preparing theold quake-resistance standards than at those by theConstruction Standards for Tsunami-hazard Areas”

new standards.

was conducted during the construction standards
preparation promotion project of the Ministry of Land,
Infrastructure, Transport and Tourism in 2011 and the“Basic Study of Structural and Evacuation Safety of
Tsunami Evacuation Buildings” was conducted in thecourse of basic research by the BRI in 2011. The
construction standards preparation promotion projectof 2011 was a joint research project of the BRI andresearchers from the Institute of Industrial Science, theUniversity of Tokyo and they submitted two interim
reports to the Ministry of Land, Infrastructure,
Transport and Tourism in July and October 2011
respectively. These interim reports included the

Photo 3.3.9.6 Collapse of furring ceilingassessment of tsunami load and tsunami evacuationbuilding design requirements based on the damage236

investigation results.

ground even after the tsunami. The flood water fromThe Ministry of Land, Infrastructure, Transport andthe tsunami reached 15.4m above ground level at the

Tourism established additional findings on the designbuilding site, and several buildings in the surrounding

method of construction for safety in the event of aarea were either destroyed or washed out. The ratio of

tsunami on November 17, 2011 and Notification No.

the lateral load carrying capacity of the first story of1318 of the Ministry of Land, Infrastructure, Transport

Building A against the horizontal tsunami load caused

and Tourism (the construction method for safety fromby hydrostatic pressure was 1.70. The building basethe estimated tsunami force while settings theshear far exceeded the tsunami load acting on it,

estimated tsunami inundation area defined on

thereby the building could survive after the tsunami.

December 27, 2011) which is a structural safety
standard for tsunami evacuation buildings based on
the interim reports.
On the other hand, the NILIM and BRI jointly
conducted field surveys starting May 2012 also, tograsp the whole damage to buildings by the tsunami.
In particular, to understand the status of damage towooden buildings, the NILIM and BRI investigated thesites in Miyagi and Iwate in May, September andOctober 2012, and discussed a calculation method on
the tsunami resistance performance of wooden
houses.

Photo 3.3.9.8 Tsunami Evacuation Building A(2) Case studies on damage to reinforced concrete

2) Case of Building B(RC) buildings

Building B is a 2-storied RC structure that is 10.5 m

The variant patterns of damage which occurred inwide, 4.5m long and 6.1m high (see Photo 3.3.9.9). It

RC buildings due to tsunami in the Great East Japanis a wall frame structure with 12 span, and is locatedEarthquake are also noteworthy. However, most of thein Onagawa Town in Miyagi. The building pile was

RC buildings survived the Tsunami, and the survival

pulled out and overturned by the force of the tsunami.

rate was estimated to be higher in the comparatively

The rate of the moment of resistance (including thenewer buildings. No serious damages or cracks in thebuoyancy acting on the building and the pile pulling-out

framework of these buildings were observed, andresistance) of the building against the overturning

even the non-structural walls did not suffer any major

moment caused by hydrostatic pressure was aboutdamage except the window glasses and doors.

79%, and the analysis result matched the actual
damage result of the overturned building.

1) Case of Tsunami Evacuation Building A
Building A, a 4-story RC structure located in
Minamisanriku in Miyagi prefecture is a public
apartment complex built in 2006. The outside stairs
could be used to escape to the roof, and it was
designated as a tsunami evacuation building (seePhoto 3.3.9.8).
Although the flood water reached about 1m above
the roof level, excluding the damage to non-structuralelements, there was no structural damage to thebuilding framework by ground shaking, and it stood237

Photo 3.3.9.9 Building B

damage investigation confirmed traces of water (5.0m)
inside the buildings and as a result, the tsunami load3) Case of Building C

acting on this wall was calculated presuming that the

Building C has 3 and 2-story RC structures locatedhydrostatic pressure behind the walls also exerted

in Onagawa in Miyagi and built in 1993 (called C-1 andforce in addition to the wave force in front of the wall.

C-2 buildings respectively as shown in Photo 3.3.9.10).

The work exerted by the external force of the tsunami

C-1 building was higher than the tsunami height, andwas 98% of the work generated by the internal force of

kept evacuees away from tsunami as a shelter. C-2 on

the building in hinge mechanism. Thus the estimatedthe other hand could not save evacuees because of

external force of the tsunami matched the actual

tsunami waves higher than the building. The ratio ofextent of damage.

st

the lateral load carrying capacity of the 1 story against
horizontal tsunami load caused by hydrostaticpressure in Building C-1 was 1.12, and proved by thefact that it could survived after the tsunami. On thecontrary, the ratio of C-2 was 0.79 and the buildingbase shear was less than the tsunami load. Despitethat it survived against tsunami in actually.

Photo 3.3.9.11 Building D
5) Case of Building E
Building E, a 2-storied wall frame type precast RC
structure built in 1970 (consisting of ribbed medium
sized concrete panels) is a public housing complex(see photo 3.3.9.12). The inundation depth in front of
Photo 3.3.9.10 Building C

the neighboring 3-story RC apartment complex was
7.5m. No significant structural damage was apparent

4) Case of Building D

in the building although it suffered damage to the gable

Building D is a 3-story RC structure located inwalls on the 2nd floor because of the colliding floating

Sendai city in Miyagi. The tsunami load acting on it

materials and also tilted from scouring of thecaused out-of-plane deformations in the outer wall,

surrounding soil.

and attached columns and beams of the building (seeAlthough the lateral load carrying capacity of the

Photo 3.3.9.11).The section of the outer wall which got

building was 37% of the tsunami wave load acting on

destroyed is well hole from the first floor to the top floor

the building that was caused by the hydrostaticwith 4 spans in the longitudinal direction.

pressure, the analysis result did not match the actual

Not the whole structure but the outer walls of thisdamage status of the surviving building. This may

section were destroyed in this building, so that thehave happened because the sea water enteredcollapsing mechanism strength due to the tsunami

through the several openings inside the building whichload will change according to the estimated folding line

must have helped in reducing the wave pressure

on the wall panel. In this study, the induced tsunami

acting on it.

load was evaluated with a hinge mechanism model byassuming folding lines on wall surface based on themeasurement result of the wall deformation. The
238

Water depth coefficient a

Figure 3.3.9.8 Water depth coefficient a estimated fromthe strength of the steel skeletons that survived
Figure 3.3.9.8 shows the investigation results of thesteel skeletons of 5 buildings. In the case of Onagawa
City (ON-S3) and Rikuzentakata City (RT-S3), where
Photo 3.3.9.12 Building E

the measured maximum water depth ηm was 14 - 15m, the range of the water depth coefficient a shown by(3) Study of damage to steel buildingsa dotted line was below 1. In the case of Taro in

Many skeletons of steel buildings remained most

Miyako City (TR-S6), where ηm was 11.5 m, the range

likely due to the reduction of the tsunami wave

of a was nearly 1. On the other hand, in the case ofpressure caused by the early breakaway of theKamaishi City (KM-S1), where ηm was value of 3.5 m,

external walls. Meanwhile, a fair number of buildings

the range of a was far beyond 1. In the case of

were found to have collapsed, have overturned, have

Ofunato City (OF-S2), where the steel skeleton

been displaced, or have been washed away. These

survived despite a low value for ‘a’, it was believed thatwere presumed to have been subjected to high wave

due to other buildings that survived on the periphery orpressure before the external walls were washed away.

in the direction of the sea, the load exerted by theInundation depth η’ corresponding to a hydrostatic

tsunami was comparatively lower in this case. Fromload equal to the horizontal load at the time of

the aforementioned results, it is inferred that in regions

collapsing of a building was taken as the “inundation

where η exceeded 10 m, since the water had gusheddepth equivalent to the building strength”, and theinto the surroundings of the building before themaximum inundation depth ηm measured in the field

maximum water depth was reached or the tsunami

investigation was taken as the “measured maximum

waves surged in from all directions, the situation of theinundation depth”. η’/ηm was defined as the waterhydrostatic load equivalent to the measured maximum

depth coefficient ‘a’ and the correlation between theinundation depth acting from one side did not arise.

damage to each of the surveyed buildings and thewater depth coefficient was studied.

(4) Study of damage to wooden buildings

The strength of a building was calculated by

In the areas where the maximum water depth was

conducting a simple plastic analysis that was based on

about less than 1-story window height (about 1.5m -the assumption of the collapse mechanism. Depending2m), almost all wooden structures remained intact.

on whether external walls assumed to be washed

Although many wooden construction buildings wereaway or not, 2 types of opening ratios were set at 0.3

washed away, in the areas where the maximum waterand 0.8. (In other words, the load reduction ratio α fordepth was 1-storey height (3m - 4m), a few cases ofbuildings without openings was 0.2 and 0.7).

buildings remaining intact were also confirmed. Whenthe maximum water depth exceeded the 1-story height(more than 4m), almost all wooden buildings including
1-story and 2-story wooden buildings were washed

Water depth (m)away.
The lateral shear capacity and tsunami load was
calculated for a wooden public housing building forwhich detailed survey was done and the values werecompared to the actual damage to verify the adequacyof the calculation formula. The wooden houses used

H for eave height239

for the study was the city-provided housing (Suzaki

verifying that the structure does not collapse, overturnHousing) of Higashi Matsushima (See photo 3.3.9.13)

or slide against the tsunami load on the building.

Figure 3.3.9.9 shows the results calculated for an

Moreover, it is necessary to verify that the pressure

areas where the water depth coefficient a = 1.0, 1.5,

resistant material used for the pressure surface

2.0. The tsunami wave load was integrated with the(surface of the building that would be subjected todirection of the height of the building and the window

direct pressure from the tsunami wave) would not be

openings were not considered. Although the water

destroyed by the wave pressure and would not lose its

depth by the damage survey results was about 4.5m.

vertical bearing capacity or resistance capacity to

Although the calculated results shows that the tsunami

horizontal force. Even in this study, the aforementioned

wave load exceed the lateral shear capacity when a =concept is being followed without any changes as a

1.0 and water depth is about 4.5m, about half thepolicy for the structural design method of tsunami

number of houses escaped complete wash-out. It wasevacuation buildings, and the 3 items shown inalso believed that the RC structure in the direction of

Table-3.3.9.4 are verified in the tsunami evacuation

the incidence of the tsunami also had an influence.

building design. Moreover, the material used forpressure surface is classified into the conventionalpressure resistant material (material designed to resist
direct tsunami wave pressure) and pressure nonresistant material (material which is allowed to be
destroyed by the impact of direct tsunami wave
pressure) and it is verified that the pressure resistantmaterial is not affected by the tsunami wave pressure.
Figure 3.3.9.10 shows the design flow in the form of apattern diagram. The structural design of tsunami
evacuation buildings is carried out by the following flow.

Photo 3.3.9.13 Intact wooden public housing
300

Table 3.3.9.4 Structural design method of tsunami

a=1.0

evacuation buildings

a=1.5

Horizontal津波による水平力
force by tsunami(kN)
(kN)

250

Bearing load in the span
direction at the 1st floor ofbuilding
279 kN

a=2.0

2001) Tsunami load lower than the horizontal strength of each story of thebuilding
2) Overturning moment lower than the resistance moment consideringbuoyancy
3) Tsunami load lower than the basic frictional force or horizontal
strength of pile
 Advisable to separately consider resistance to horizontal motion
 Pressure resistant material used in pressure surfaces should remain
under tsunami pressure

150

100

50

0
1.5

2

2.5

3

3.5

4

4.5

5

浸水深 (m)Water depth(m)Figure 3.3.9.9 Relationship between lateral shear
capacity and tsunami wave load(5) Study of the structural design method of tsunami
evacuation buildings“The basic concept of structural requirements” isgiven at the end of the document (2) of the “Guidelines
for Tsunami Evacuation Buildings”

22)(referred to as‘the guidelines’ hereinafter in this section) given by the
Cabinet Office in 2005, based on the results of an
independent study conducted by the Building Center ofJapan in 2004. It contains information that is helpful in240

Calculation of pressure
from the tsunami wave

Calculation of buoyancy

Calculation of force fromthe tsunami wavea) Buoyancy
used todesign theupper
structure

Calculation of shear forcesin each layer(relatively simple constructions and buildings), and thewater depth coefficient equivalent to the strength of thestructureb) Buoyancy
used todesign thefoundation

while

presuming

hydrostaticpressure

distribution was reverse calculated using the measured
water depth at the site. Furthermore, as a result of
hearings

Design of pressure-withstanding
material

conducted

withexpertsontsunamiengineering, the concept that the wave pressure of thetsunami in the Great East Japan Earthquake is not

Examination on driftwoods

necessarily the imagined maximum and it is not
appropriate to amend the maximum value of wave

Examination on scouring

pressure only based on the damage was introduced.
Examination on collapse

The conventionally believed equation of “hydrostaticpressure = 3 times the designed water depth” wasExamination on
overturn

taken as the case of maximum wave pressure acting
on the structure and the scenarios where the water

Examination on slide

depth coefficient a could be reduced were investigated.

Design of footing beam

The water depth coefficients obtained as a result of thisFigure 3.3.9.10 Structural design flow of Tsunami

are given in table-3.3.9.5 and the details of the studies

evacuation buildings

related to water depth coefficients are given in 1) and2) below.

In the guidelines, it has been given that the water
depth coefficient a should be taken as 3 and theTable 3.3.9.5 Setting water depth coefficient atsunami wave pressure should be created by applying
Distance fromcoast or river,etc.
Setting of waterdepth
coefficient ahydrostatic pressure, three-times the water depth in
the design, on one side. This was a proposal given by
Asakura et al. in relation to the tsunami pressure acting

There is a shielding object

No shielding object

500m orfurtherLess than
500m

Does not depend on
distance

1.5

2

3

on the building in the form of tidal wave run-up on land
after overflowing the upright seawall, and it was based

1) Study Item 1 (Influence of shelter/cover)on the results of mock tests conducted by varying the

A case where masking was used to reduce thelocation of the structure, the slope gradient of the water

wave pressure of the tsunami from the incident

way,

or

directions was taken up whereby the water depth

wave-pressure

coefficient a would be reduced. In the study, in addition

distribution was triangular distribution, and its heightto other buildings around the building, a seawall at thewas almost 3 times the water depth. In other words,

entrance to the bay or a seawall or breakwater ofthe influence of underlying flow velocity has been

sufficient height (estimated to be at least more than ½

included in the formula for calculating tsunami wave

the height of the tsunami wave) considering the heightpressure generated by hydrostatic pressure.

of

wave

wave-height,

characteristics
the

fact

that

such
the

as

cycle,

thetsunami

wave

were

consideredas

In this study, based on the results of the fieldshelters/covers expected to reduce the wave pressure.

investigation, the “3” in the wave pressure calculation

As a result of the study, when the water depth

method in the “guidelines” was believed to be variable

coefficient a in case of masking expected to reduce thedepending on the momentum of the tsunami (Froude

wave pressure of the tsunami was compared to thenumber), and this “3” was kept as “a (water depthcase where masking was not used, it was understoodcoefficient)”, and ‘a’ was verified based on the damage

that masking reduced the pressure by 1/1.5. Thus, it

facts. In this verification, the strength was estimatedwas possible to bring the water depth coefficient a todepending on the type of damage to the structure2413/1.5 i.e. “2” when the masking is expected to reduce
the tsunami wave pressure.
2) Study Item 2 (Impact of distance from the coast or
river)A case related to the distance from the coast or river
was taken up where the water depth coefficient a
could be reduced. From the study it was derived thatthe momentum of the tsunami (Froude number)
reduces according to the distance from the coast or
river, and in case where the distance from the coast or
river is more than 500m, it was possible to show that a= about 1.0. Furthermore, taking into considerationthat this study was confined to the data obtained fromthe field investigations, that strength calculation was anabbreviated calculation, that there was variation in themeasured water depth and the water depth based on
the tsunami simulation, a maximum margin of 1.5
times was allowed in the results of the field
investigation. Hence, the water depth coefficient awhen masking was used and the distance was morethan 500m away from the coast or river was taken as
about 1.5. Furthermore, it is necessary to ascertainthat there are no elements that may increase the flow
velocity due to factors like a downslope or building
layout that can concentrate the flow while paying
attention to the topography of the region surrounding
the building.

242

3.3.9.4 Damage to buildings from firefrom 6pm to midnight. The factors leading to fire(1) Fire investigation summary

outbreaks immediately after the earthquake are; fire

The Great East Japan Earthquake followed byequipment and ceiling gadgets such as electric stovetsunami caused numerous fire outbreaks mainly in theand waste oil stove in use, electrical substationprefectures on the Pacific Ocean, between Aomori andequipment and electrical wiring related devices.

Chiba prefectures, and in the Tokyo Metropolitan area,

In many cases, fire broke out in residential buildings,

Saitama and Kanagawa prefectures. A summary of

but due to effective firefighting operations, only 1

the result of investigation of the fires is given below.

residence was burned in about 70% of the fires.

(For details, refer to National Institute for Land andAmong the all tsunami-flooded areas, the total fire

Infrastructure Management, Technical Note No. 674).

spread area went up to 72 ha, and there were a total of

The fire outbreak caused by the Great East Japan

7 territories, namely, Miyako City (Taroariya district),

Earthquake was characteristic of; widespread fire

Yamada Town (heart of the city), Otsuchi Town (central

outbreak at numerous locations, large-scale firepart),

spread in tsunami-flooded areas, and large-scale fire(Southwest coast), Ishinomaki City (Kadowaki district) ,outbreaks at petroleum complexes.

and Natori City (Yuriage district), in which the area

Kesennuma

City(Shishiori

district)

andThe areas most affected by the fire include theburnt down by fire spread reached up 3.3 ha (10,000

regions damaged due to tsunami flooding, Tokyotsubo) or 3.3 ha (33,000 square meters). Even in themetropolitan surroundings, urban areas of Chiba andGreat Hanshin-Awaji earthquake of 1995, the total fire

Yokohama city. Besides, these were the areas thatspread area was about 63 ha, and similar to this time,

were hit by earthquakes measuring upper-5 on the

7 territories had more than 3.3 ha area burnt down byJapanese scale.

fire. Besides, it has been confirmed that there areConsidering the number of fires (a percentage of fire

many regions that still have several nearby but

outbreaks) per municipality per 10,000 households,

discontinuous traces of fire. Out of 29 confirmed

greater the earthquake intensity higher is thetsunami fire cases, almost 21 cases are related topercentage of fire outbreaks. A significant difference is

vehicle fires caused by natural fire outbreak due toseen in the percentage of fire outbreak between

insulation failure of electric components subsequent tointensity of over lower-6 and less than upper-5. Thus, it

the tsunami flooding. In the territories that sufferedshows the same tendency as the Mid Niigata

massive fire, it was the collapsed houses and vehicles

prefecture earthquake of 2004. However, if we

swept away by tsunami waves that spread the fire.

calculate the fire outbreak rate by classifying it into
tsunami specific and non-specific fire outbreaks, therate of municipalities suffering no damage fromtsunami flooding (approximately 1.0 per 10,000
households) was about 1/4th of that of the Mid Niigata
prefecture earthquake (approximately 0.25 per 10,000
households in the regions where earthquake intensity
is greater than upper-6) whereas the fire outbreak rateof municipalities that suffered tsunami flooding wasextremely high at 8.14 per 10,000 households.
Interviews with residents living in the vicinity and FireFighting head office were conducted to obtain
information related to individual fire cases.
Incidents of fire outside the tsunami-flooded areas
mainly occurred immediately after the earthquake, andkept occurring until April 15, mostly during the hours2433.3.9.5 Response based on Building Damage• The draft of technical standards concerning(1) Particulars of response based on building damage

measures to prevent the fall of escalators

NILIM and BRI jointly started investigating damage•

to buildings from the next day when the earthquake

Measuresagainstlong-period

earthquake

motions

occured.

Round 5 (October 22, 2012)

Later the data of damage investigation results from• Measures for ensuring safety of buildings against

both NILIM and BRI were published on their websites

damages caused by the Great East Japanas Technical Note of NILIM and BRI Research Paper.

Earthquake

As a summary of last report published in March• The draft of technical standards concerning

2012, following challenges need to be addressed.

measures to prevent the fall of ceilings① Measures against tsunami• The draft of technical standards concerning② Measures to prevent damages of non-structural

measures to prevent the fall of escalators

elements like ceilings

Based on these discussions, the guidelines③ Measures against long-period earthquake motions

concerning structural requirements for tsunami-④ Measures against liquefaction damages

evacuation buildings were revised (as Notified by a

NILIM established the Building Structure Standards

Director General, Housing Bureau on November 17,

Committee (Chairman:Tetsuo Kubo, an honorary2011) and were incorporated in publication of technicalprofessor of Tokyo University) in April 2011 to study thestandards for specific evacuation facilities based on

proposed technical standards in the structure field. The

thecommittee initiated the study of measures in building

Tsunami-resistant Communities (Notification no. 1318

architecture against damages caused by the Greatpublished by Ministry of Land Infrastructure and

East

field

Transport on December 27, 2011). Public comments

investigations on April 21 and 22, 2011 (see photo

was also invited from July 31, 2012 on the draft of

3.3.9.15)

technical standards concerning measures to prevent

Japan

Earthquake

andconducted

The committee discussed the measures as follows.

Act

concerningtheDevelopmentofthe fall of ceilings and escalators.

Round 1 (June 18, 2011)

Further, due to the long-period earthquake motions,• Damage survey for buildings

significant shakes were recorded on a skyscraper• Measures against Tsunami

located about 700km away from the origin of• Measures to prevent damages of non-structural

earthquake. Based on this data, the committee

elements like ceilings

established “Working Group for investigation of•

Measuresagainstlong-period

earthquake

measures against long-period earthquake motions”

motions

and continues to investigate the same.

Round 2 (August 18, 2011)• Measures against Tsunami• Measures to prevent damages of non-structuralelements like ceilings
Round 3 (October 13, 2011)• Measures against Tsunami• Measures against long-period earthquake
motions
Round 4 (July 9, 2012)• Situation of response to the Great East Japan
Earthquake

Photo 3.3.9.14 Buildings damaged by tsunami• The draft of technical standards concerning
measures to prevent the fall of ceilings244

(2) Survey details of analysis of buildings damaged bytsunami and technical standards

During their investigation research, the Institute of1) Damage analysis and creation of guidelines on

Industrial Science, University of Tokyo and the Building

constructional

Research Institute presented the first interim report on

requirements

for

the

tsunami-July 7, 2011 and the 2nd interim report on Oct 10, 2011.

evacuation buildings
Tsunami-damaged buildings were seen in a wide

Based on these accomplishments, the NILIM createdarea in coastal regions. The NILIM and BRI

a draft of technical standards and prepared a design

investigated the damage to buildings at the field survey,

model

and based on the results of the investigations thediscussions with Building Construction Standards

technical standards for construction design methods

Association in the Ministry of Land, Infrastructure,

for the tsunami-evacuation buildings was reviewed.

Transport and Tourism.

fortsunami-evacuationbuildings

after

In the course of this investigation, unlike analysis ofThis section reports on the technical standards.
In the Great East Japan Earthquake, many buildings

damage by ground shaking, it was necessary towere destructed and damaged owing to Tsunami,

assume the external force generated by tsunamis onwhich highlighted the importance of ensuring structural

each of the damaged buildings, however in the fieldsafety of tsunami-evacuation buildings used assurvey, the information required for assuming the

temporary shelters to cope with tsunami. As a result,appropriate external force was not sufficient and the

Housing Bureau, the Ministry of Land, Infrastructure,

NILIM also conducted the investigations with theTransport and Tourism and the NILIM immediately

cooperation of the River Department and Building

conducted studies related to design methods for

Department.

structural safety of buildings to cope with tsunamis.

Herewith, the existing guidelines (“guidelines on

Particularly in FY 2011, under the Building Standards

tsunami evacuation buildings” (by the Cabinet Office in

Maintenance Promotion Program (subsidized project2005), hereinafter referred as “the Cabinet Officeof Housing Bureau, Ministry of Land, Infrastructure,

Guidelines”) were referred for setting the tsunami

Transport and Tourism) investigation research agendaloads in structural design methods, and considering

was set as “40. Investigation on maintenance ofthe site situations, etc., the hydrostatic pressure whichconstruction standards in Tsunami hazard area”, andwas set to 3 times the inundation depth was relaxed

the public offering of operating bodies started fromdown to hydrostatic pressure of 2 or 1.5 times of theApril, 2011. Thus, the Institute of Industrial Science,

inundation depth. Also, overturning caused by

University of Tokyo (Prof. Yoshiaki Nakano) selectedbuoyancy was investigated and designs were clarified

as the operating body started the investigative

to protect against scouring, collision of debris, etc.

research in partnership with “Earthquake Resistance

As for the technical standards, the Director-General,

Renovation Support Centre (Japan Building Disaster

Housing Bureau of the Ministry of Land, Infrastructure,

Prevention Association) and the Building Research

Transport and Tourism provided additional findings on

Institute.

design methods for structural safety of buildings tocope with tsunamis (Notification No. 2570.3 dated
November 17, 2011)”, to all the prefectural governors
in the form of “tentative guidelines concerning
structural requirements such as tsunami-evacuationbuildings (hereinafter referred as “guidelines”) basedon buildings damaged by tsunami subsequent to theGreat East Japan Earthquake.”

Photo 3.3.9.15 Field Survey by Building Construction
Standards Association (Onagawa Town)
2452) Tsunami Disaster Prevention Area Construction Act

The points sorted on the aforementioned guidelines

For reconstruction of areas extensively damaged byand technical standards notification (hereinafter

the tsunami, and for prevention and reduction ofreferred as “guidelines”) are shown below (Fortsunami damage in the future, it is necessary to

overview, see Fig. 3.3.9.11).

promote tsunami disaster prevention area construction

Tentative guidelines concerning structural requirements such as tsunami-evacuation buildings: Created by the Housing Bureau and the NILIM (as notified by the Housing Bureau on
November 17, 2011)
Publication of technical standards based on the Tsunami Disaster prevention Area Construction
Act (December 27, 2011)
Main reviews

with the help of “multiple defenses” inclusive of hardand soft policies and measures. Therefore, the “Actrelatedtotsunamidisasterprevention

area

Rationalization of setting the tsunami burden

construction” (Act No. 123, 2011, hereinafter “Tsunami

Existing guidelines(Setting based on experiments) Rationalization
based on thisSet to 3 times the hydrostatic
time’spressure of the inundation level earthquake

Disaster Prevention Area Construction Act” wasannounced as framework through Diet deliberations in① In the case that the reduction effect is anticipated 2.0

by levees or frontal buildings② For ①, in the case that the distance from thecoastal line is apart (500m or far)

③ In the case except ① and ②
Design supporting
inundation level

December 2011.
The specified evacuation establishments pointed in
the Tsunami Disaster Prevention Area Construction

times
1.5
times
3.0
times

Buildings

In addition, for burden calculation, to specify the following①Enable reducing the wave force by inflow into openings (windows etc)
②Exclude open sections in stilts from the burden calculation* Besides the abovementioned, clarify examination on overturn by buoyancy,
considerations to scouring and collision by driftwoods on designing

Act are equivalent to the aforementioned tsunamievacuation buildings, and must meet the following

Figure 3.3.9.11 Overview of technical standards related

criteria.

to structural requirements for tsunami-evacuation① Conform with the technical standards created bybuildings

the Ministry of Land, Infrastructure, Transport andTourism as structures safe against tsunami(a) Calculation formula of Tsunami wave load

② Having safe rooftops or other places that are higher① Tsunami wave pressure calculation formula

than the design water depth to be used for

The Cabinet Office Guidelines provided the formulaevacuation, and safe stairways or routes to reach tofor calculating the tsunami wave pressure as

such placeshydrostatic pressure equivalent to 3 times of③ Conform to given standards for management ofinundation depth for design, however, the calculationbuildings, that is, opening the stairways or routes toformula in the guideline was revised on the basis of the

public at tsunami disaster, and etc.

results of collaborative research by Institute of

Based on the contents of the aforementioned

Industrial Science, University of Tokyo and the Building

guidelines, the technical standards mentioned in point

Research Institute.

① are being standardized as the Notification “theconstruction method for safety from the estimatedtsunami force while settings the estimated tsunami
inundation area defined on December 27, 2011
(Notificationno.

Infrastructure,

1318

by

Transport

Ministry

and

of

Land,

Tourism,

2011,

hereinafter referred as “technical standards notification”
based on Article 31 of the Ordinance for Enforcementof the said Act, and the act related to tsunami disasterprevention area construction.
(3) Overview of technical standards related totsunami-evacuation buildings, etc.
1) Points on technical standards related to structuraldesign methods

246establishments or other buildings in tsunami invasion
qz=ρg(ah-z)

direction from tsunami evacuation buildings in which

Buildings

the reduction effect can be anticipated, the water depth

Design supporting
inundation level

coefficient can be decreased from 3.0 to 2.0. Whereas,ahwhen the tsunami evacuation buildings are locatedz

500 m away from the coast or river in the tsunamihinvasion direction, it can be decreased from 2.0 to 1.5.

aρgh

② Tsunami wave force calculation formula
The tsunami wave pressure in tsunami run-up

The tsunami wave pressure of ① represents the

direction was calculated for structural design using thetsunami wave force per unit area, so the tsunami wave

following formulaforce can be calculated by integrating the tsunami
wave pressure with wave loading area.

qz =ρg(ah－z) • • • (i)Formula (ii) is used for calculating tsunami wave

Here,
qz: Tsunami wave pressure in tsunami run-up direction

force when the minimum height of wave loading area

for structural design (kN/m2)

is z1, and maximum height is z2 (Fig-3.3.9.13). Further3

it is assumed that the width of wave loading area inρ: density of water (t/m )2

g : gravity acceleration (m/s )building was different from the height and it was

h : Inundation depth for design (m)decided to integrate it with width B of wave loadingz : Height of said part from ground levelarea.

(0≦z≦ah) (m)a : Coefficient of depth of water. Set to 3. However,Formula (ii)when it corresponds to the requirements mentioned in
the following table, it can be considered as the

Buildings

Design supporting ahinundation levelnumerical values given in column “value of a”
respectively. (Note: this coefficient does not represent

ｚ２ ｚ1

ｈ

the degree of rise in water level due to tsunami afflux infront of buildings, etc.)
(1)

aρgh

Requirements

Value of a

When establishment or other buildings are

2

Tsunami wave force in tsunami run-up direction forcovering the tsunami evacuation buildings instructural design is calculated using the following

tsunami coming direction ( only the case when

formula, assuming that the tsunami wave pressure

efficient mitigation of water flow can be

is generated at the same time.

anticipated)(2)

In case of (1), when tsunami evacuation buildingz2
Qz=ρg z 1 (ah – z) Bdz • • • (ii)1.5

is located 500m away from the coast or rivers

Here,

Figure 3.3.9.12 Tsunami wave pressure calculation

Qz : Tsunami wave force in tsunami run-up

formuladirection for structural design (kN)
B : Width of wave loading area in said part (m)Therefore, a hydrostatic pressure equivalent to 3

z1 : Minimum height of wave loading area (0≦z1≦

times of inundation depth for the design wasz2) (m)standardized and it was decided to decrease thez2 : Maximum height of wave loading area (z1≦z2≦

scaling factor (defined as water depth coefficient aah) (m)derived from formula (i)) when it is estimated that the

Figure 3.3.9.13 Tsunami wave force calculation formulaforce of tsunami can be reduced (Fig-3.3.9.12).
Specifically, when there is a obstacle such as
247

The width B of wave loading area does not always

established.

constant from the base to the top, and therefore,(d) Horizontal load direction

integration is done by using the each width of wave

Particularly, the geography around estuaries andloading area at the each height.

harbors is complex and since it is difficult to assume(b) Reduction due to openings

the tsunami invasion direction, it was provided in the

In the guidelines, after obtaining the damage

guidelines to assume that tsunami is going to generate

investigation results for reduction efficiency of tsunami

from all the horizontal load directions. As a general rule,wave force by openings, it was decided to specify thein this case a equivalent wave pressure was assumed

reason of excluding tsunami wave force in openings

infrom the calculation as a general rule of the tsunami

orthogonal direction (Y-direction). Moreover, for thewave force prior to exclusion not being below 70%. Inback wash also it is appropriate to estimate the samethe calculation of tsunami wave load for structural

wave pressure.

tsunamirun-updirection(X-direction)anddesign of the building, the “openings” mentioned here

However, the tsunami run-up direction can be

are in the wave loading area and are assumed to be

specified with plain geography and proper application

non-pressure resistant components that can beof numerical simulation results exceptionally, but aconfirmed destruction.

careful examination will be required in those cases

As for the method of wave force mitigation, 2

since the tsunami invasion direction may change

methods have been shown; ① calculation method in

depending on the analysis assumption of numericalwhich sum total of width of opening is excluded fromsimulation, positioning of surrounding structures, etc.

the width of wave loading area, and ② calculation(e) Calculation of buoyancy

method in which the wave load discount in proportion

Some buildings were found to have overturned due

to a reduction factor derived from a ratio of residual

to the tsunami in Great East Japan Earthquake. In

wave loading area excluding opening area to the totalsuch buildings, the piles did not have sufficient

wave loading area.

resistance to bear the overturning moment by tsunami

In ①, calculation is done by excluding the sum total

including buoyant force.

of opening width from the tsunami wave loading area

Based on the field survey results, it assumes thatin each story. When the wave force integrated bybuoyant force may generate corresponding to the

excluding the opening width is smaller than 70% of the

cubic volume under the inundation depth at thewave force on the tsunami wave loading area,

maximum, while on the other hand, many cases were

excluding opening width reduce according to aobserved wherein there was reduction by water inflow

coefficient in which the total wave force has beenfrom the openings.

adjusted to reach 70% of the wave force on theBased on such results, since water inflow inside thetsunami wave loading area.

buildings cannot always be anticipated when the

In ②, wave force is equal to (reduction rate) = 1 -tsunami water level is rising at a great speed, the(total of opening area / tsunami wave loading area),guideline was sorted considering the buoyancy

and the above reduction rate must not be smaller thanproportionate to the inundated building cubic volume

0.7.

(including volume of internal spaces), and it was

The lower limit of aforementioned reduction rate isdecided that the volume rate can be deducted fromset to 0.7 since the reduction efficiency of wave force

buoyancy only in cases when the volume of water

decreases if there are any inner walls, etc.

flowing into the buildings (inundation volume) can be

As for handling of open sections such as piloti, it wascalculated. In such cases, it is necessary to consider

decided to clarify the exclusion of the tsunami wave

buoyancy of volume rate of the skeletons itself.

pressure on open sections as well as the openings in(f) Special investigations and studies

the guidelines. As for the open sections, unlike theIn order to provide future support for development of

openings, a lower limit of reduction rate was notresearch and study, regulations on “depth water248

coefficient according to appropriate numerical values

2) Technical manual and design examples

for calculations based on special research or studies”

The aforementioned technical standards notification

have been incorporated in the guideline.

was announced and enforced on December 27, 2011,

At the present, it is assumed that value of abut for providing technical support to the structural

decrease according to the Froude number Fr (Fr =designers, the National Institute for Land andInfrastructure Management undertook the work ofu/ gη, here u: flow velocity, g: gravity acceleration, η:

creating technical manual and design examples

inundation depth. Higher the Froude number, stronger24), 25)

the flow force) shown in report

including above contents and guideline. The creatingof aforementioned

manual and examples has been totally supported bybuildings code revision promotion project.

Building Research Institute.

(g) Design flow of the buildings

Moreover, it created the design examples with the

The guideline shall confirm the strength of buildings

cooperation of the Urban Renaissance Agency, Japanagainst the tsunami load. Specifically, the following

Structural Consultants Association.

items were validated.

The design examples were based on the existing① There is no destruction of pressure-resistantreinforced concrete residential complexes with thecomponents due to tsunami wave pressure

purpose of providing an actual calculation process,② The horizontal load bearing strength exceeds theand cases having the following different inundation

tsunami wave force in each direction and each floor

depths were created; ①design example assuming③ Considering the buoyancy and self-weight, theinundation depth of 10m and water depth coefficient abuilding does not get overturned or slide due to the= 2.0 , ②design examples assuming inundation depth

tsunami loadof 15m and water depth coefficient a = 2.0④ It should be designed to consider soil erosion and

The important notice in detail design clarified throughimpact load by debris (Fig-3.3.9.14).

the creation of design examples were incorporated in
the technical manuals. Those contents are also

Calculation of pressure from the tsunami wave
Calculation of force from the tsunami wave

compiled as a National Institute for Land andCalculation of buoyancy

Infrastructure Management Report (no.673)

4)

, and

lectures has been carried out for the managers of local

Design of pressure-withstanding material

government based on lecture notes with additional

Examination on driftwoods

design examples under Ministry of Land, Infrastructure,

Examination on scouring

Transport and Tourism subsidized projects.
3) Overview of design example

Design of the structural framework

This section provides an overview of the design

Examination on collapse
Examination on slide

examples.

Design of footing beam(a) Reinforced concrete construction of 6 storied
residential complex

Figure 3.3.9.14 Design flow (overview)

This building was designed to carry tsunami wave
load in case of 10m inundation depth with the water(h) Other design-related considerations
Guideline recommended pile foundations, or spread

depth coefficient a being 2.The original design was anfoundations which have provision to protect the incline

8 storied residential complex but was revised to 6of the building considering corrosion. Further, forstories (Fig-3.3.9.15).

preventing damage due to debris impact, it was

The desired load carrying capacity was confirmed

ascertained that the major element consisted frame

by increasing the thickness of load bearing walls ([ex:structure does not damaged or the destruction in a

1 story] 230 mm in original design -> 350 mm forpart of columns or load bearing walls do not cause

evacuation building), increasing the piles (18 piles incollapsing of the whole building by debris impact.

original design -> 20 piles for evacuation building), and249

changing the pile diameter (1300φ in original design ->Shared hallway

1900φ for evacuation building).

Balcony

Shared hallway

Balcony

Balcony

Dwelling unit

Dwelling unit

Balcony

Balcony

Dwelling unit Dwelling unit Dwelling unit Dwelling unit Dwelling unit Dwelling unit
Balcony

Balcony

Balcony

Balcony

Balcony

Balcony

Balcony

Dwelling unit

Dwelling unit

Dwelling unit

Dwelling unit Dwelling unit

Dwelling unit

Dwelling unit

Dwelling unit

Balcony

Balcony

Balcony

Balcony

Balcony

Balcony

Balcony

Balcony

Ground plan of the standard story

Ground plan of the standard story

Elevation plan on the south side

Usage
Number of stories
Building heightStandard floor height
Structure type
Foundation type

Housing complex
6 stores above ground, 1 rooftop structure
18.07m
2.85m
Longitudinal direction bare frame structure
Transverse direction wall frame structure
Piled foundation (concrete composite steel pile cast inplace)

Usage,
Number of stories
Building height

Housing complex
8 stores above ground, 1 rooftop structure
23.77mStandard floor height
Structure type

2.85m
Longitudinal direction bare frame structure
Transverse direction wall frame structure

Foundation type

Piled foundation (concrete composite steel pile cast inplace)

Figure 3.3.9.16 Design example (2) overview

Figure 3.3.9.15 Design example (1) overview(4) Backing up measures related to support for(b) Reinforced concrete construction of 8-storied

damage to buildings by ground shaking

residential complex

1) Response to ceiling collapse damage

This building was designed to carry tsunami wave

The Great East Japan Earthquake caused muchload in case of 15m inundation depth with the water

ceiling damage in many buildings over a wide area.

depth coefficient a being 2. The original design is

The survey by the building standards development

same as the one mentioned in (1) (Fig. 3.3.9.16).

promotion project showed that more than 2000

The required load carrying capacity was confirmed

buildings suffered ceiling damage.

by further increasing the thickness of load bearing

Conventionally, the Order for Enforcement ofwalls (Ex: 1 story) maximum 500mm), increasing the

Building standards Law has stipulated that the ceilingpiles (18 piles in original design -> 34 piles forshould not fall by ground shaking. No specificevacuation building), and changing the pile diameterengineering standards have been defined and the(1300φ in original design -> 2000φ for evacuation

countermeasures have been given in the technicalbuilding).

advice.
After the disaster, a survey item 41 "a researchstudy for the promotion of the seismic standards on
nonstructural components with regard to the Great
East Japan Earthquake" was announced as a part ofthe building standards promotion project. The Building
Performance Standardization Association took thesurvey item and formed a committee to examine thedamage and work on the seismic design of suspended
ceiling chaired by Isao Sakamoto, a Professor
emeritus at the University of Tokyo.
Based on this result, the ceiling seismic design STG

250

made a standard draft, which was established underhousing bureau of MLIT and the NILIM between July

the technical standards draft TG of the NILIM building

31, 2012 and September 15, 2012 after somestructural standard committee.

modifications reflecting the comments by the NILIM
building structural standard committee.

Outline of the draft of technical standards for safety of prevention of collapse ceilings⑥Ceiling members appropriately transmit the stationary load and theseismic load to the structural members bearing the loads. The
suspending members are connected tightly to the structural members.

2) Measure to prevent the fall of escalators②Materials consisting of ceilings have sufficient bearing
forces against an anticipated load
⑫Ceilings are installed with enough clearance from eachother at seismic expansion joint.

⑧Bracing members arearranged well-balanced
in a V shape elevation in
X and Y directions.

By the Great East Japan Earthquake, it was
confirmed that 4 escalators fell in commercial facilities,③1 suspending rod
covers not more than 1 m2

although no one was fortunately hurt.

⑦Suspending member
measuring 1,500mm ormore needs horizontal
stiffening member.

⑪The ceiling is at aclearance of 100 mm ormore from the surrounding
elements and equipments.

With regards to the installation of escalators, the④Hanging length
does not exceed 3m.

⑬Ceiling planes withrelative seismic
displacement (forexample, at the level
difference or the fold) needenough clearance fromeach other.

⑩Bracing members
are at 60 degrees orless against thehorizontal plane(ceiling plane)⑨The joints of bracing members
and adjoining members areconnected tightly in order totransmit the seismic load on theceiling appropriately to thestructural members (a welding
connection is not allowed.)

Building Standards Law has not any specific①The unit mass ofceiling per square
meter is over 6kg anddoes not exceed 20kg

regulations for the structural framework. The industrial
guideline (which is not⑤Ceiling materials consisting of ceilings arebound together tightly to avoid sliding andunfastening against the stationary load and theimpact load and deformation by earthquake

compulsory legislation)requires that the bearing width should be more than
1/100×height of an escalator＋20mm.

Figure 3.3.9.17 Summary of the “specification route”

Based on the current damage, in order to promote

for prevention of ceiling collapse

the arrangement of the data required for damage
analysis and technical requirements, the research

The draft had three routes applicable to the ceilings

subject [45. Review for the earthquake safetysuspended at 6m or above and covering more than

measures with respect to lift and escalator] has been

2

200m . The routes

were "specification route",

set up under the Building Standards Maintenance"calculation route" and "special verification route."

Promotion Program. In the Building Performance

The specification route had criteria according to theStandardization Association which was elected by theunit mass of the ceiling such as a tight connection

general invitation, the committee of experts was set up

between each ceiling member to avoid any damage or

and the technical survey concerning the damage

fall during an earthquake, a well-balanced layout ofanalysis and measures to prevent the fall of escalators

sufficient bracing members to diminish harmful

was promoted.

resonance, a sufficient clearance between the ceiling

Based on this result, the draft of technical standards

and the surrounding members and a sufficient

to prevent the fall of escalators were made by theclearance at the level difference and others to avoid

Housing Bureau and NILIM through the deliberations

the collision. The route also allowed fail-safe measureson the Building Structure Standards Committee. The

like extending the net beneath the ceiling or hooking

draft requires that the bearing width should be more

the ceiling members with wires.

than 1/40×height of a escalator＋20mm and so on.

The calculation route had criteria for verification: ①

Public comments was invited on the draft between

no damage with a load three times of the dead load,

July 31 and September 15, 2012, And the technical② no damage to the members and the joints with thestandards based on these results are scheduled to beinertial force calculated by the spectral method, thearranged.

simple spectral method or the seismic coefficientmethod considering the acceleration on the ceiling

3) Measures for Exterior material collapse damage

surface, ③ no collision to the surrounding walls andWith regards to the damage caused to the exterior

others with a clearance more than the calculatedmaterial in the Great East Japan Earthquake, falling ofhorizontal displacement.

ALC panels of large commercial buildings, exterior wall

The special verification route was also made totiles, mortar etc was reported but fortunately there wasenable individual verification.

no human fatality involved. However, although there

A public comment for the draft was conducted by thewas no report of any major damage to the main251

structure, there were many damages such as lifting or

earthquake ground motion were announced inpeeling of the outer walls which were finished with tiles

December 2010 prior to the Great East Japanor mortar.

Earthquake. Public comments were collected and theWith regards to the finished materials including

study shall continue based on the comments received.

exterior materials, the construction method wasRegarding the countermeasures for liquefaction,

specified in Article 39 of the Building Standard Law

simple diagnostic method for detached houses etc, will

Enforcement Order and Notification No. 109 of thebe continued to be investigated in the building

Ministry of Construction of 1971, however, technicalstandards development promotion project.

standards including the standard for method ofmounting are not yet developed.

References

Based on the recent situation of damage, the3.3.9.2 Damage caused to buildings by earthquakes

upgrading of the law or technology and standards

1) National Research Institute for Earth Science andrelated to the earthquake-proof safety in order to target

Disaster Prevention: Strong motion observation

the insufficient the exterior materials like tile/mortar etc.,

network (K-NET, KiK-net)① establishment of the technology and standards for

http://www.kyoshin.bosai.go.jp/kyoshin/

the spalling prevention considering the earthquake-2) Ministry of Land, Infrastructure, Transport andproof safety of the external materials, ② aiming at the

Tourism:

establishment of the method to evaluate theArchitectural survey committee report – combinedsoundness of the external materials post theversion- 1996

1995

Hanshin/

Awaji

Earthquake

earthquake, is planned to be carried out from 2012 for3) Architectural Institute of Japan: Hanshin/Awaji

the period of 3 years [Research on methods andEarthquake and future RC structure design-

criteria for evaluation of the seismic safety exterior

Causes of characteristic damage and thematerial] by NILIM.

proposal of design

Also, prior to this, in 2011, as for the public facilities,

4) Japan Building Disaster Prevention Association:by implementing the earthquake damage investigation

Classification Criteria of the degree of restorationof the external materials caused by the Great Eastof the buildings affected by the earthquake andJapan Earthquake the manufacturing and construction

technical guidelines for restoration, 2001

method, a number of case studies were collected on5) National institute for Land and Infrastructure

the relationship between damage such as peeling andManagement, Building Research Institute: 2004

lifting etc. Moreover, with regards to the tile walls using

Niigata Chuetsu earthquake building damageorganic adhesives which is increasingly applied in thesurvey pp.305-353, 2006

recent years, by collecting data from the survey of6) Takashi Hasegawa, Akiyoshi Mukai, Kazuo

industry associations, wide range of the earthquake

Nishida, Tadashi Ishihara: Steel gymnasium

damage data related to the exterior materials wasdamage investigation in the Niigata Chuestu

summarized.

earthquake (Part 1 Structural damage analysis),
Summaries of Technical Papers of Annual

4) Future investigation topics

Meeting of Architectural Institute of Japan,

With respect to long-period earthquake ground

Structure II, pp.569-570, 2005

motion, the NILIM Building Structural Standard

7) Kazuo

Nishida,Akiyoshi

Mukai,

TakashiCommittee set up the long-period earthquake ground

Hasegawa, Tadashi Ishihara: Steel gymnasium

motion review WG. Taking into account the status ofdamage investigation in the Niigata Chuestu

the examination conducted by the Central Disasterearthquake (Part 2 Damage analysis of theManagement Council and the Headquarters for

nonstructural member), Summaries of Technical

Earthquake Research Promotion, the study has been

Papers of Annual Meeting of Architectural Institutecontinued.

of Japan, Structure II, pp.571-572, 2005

Tentative

measuresoflong-period2528) Architectural

InstituteofJapan:

DesignSymposium, Kinki Branch, Architectural Institute of

Recommendations for Composite Constructions,Japan, pp. 19-20, 2009 (in Japanese).

201120) Yoshimi, Y.: Liquefaction of Sandy Soils, Gihodo

9) Ministry of Education, Culture, Sports, Science

Publication p.182, 1991 (in Japanese).

and Technology: Seismic retrofitting manual for21) Seed, H. B., Idriss, I. M., and Arango, I.:

School Facilities, Steel Gymnasium (2003 revised

Evaluation of Liquefaction Potential Using Field

version), 2008

Performance Data, J. Geotechnical Engineering,10) Japan Building Disaster Prevention Association ,Japan

Association

for

Building

American Society of Civil Engineers, Vol. 109, No.

Research

3, pp. 458-482, 1983.

Promotion: Guidance and examples of the
Seismic retrofitting of existing steel gymnasium etc.

3.3.9.3 Building damage caused by Tsunami

for structural engineers, 2005

22) Cabinet Office: Guidelines issued by Tsunami11) National Institute for Land and Infrastructure

Evacuation building, 2005

management: Survey and Research Report on
the

2004

Niigata

Chuetsu

Earthquake,

3.3.9.4 Fire Survey Overview

pp.176-223, 200623) National Institute for Land and Infrastructure12) Japan Meteorological Agency: Strong motion

Management and Building Research Institute:(2011 Great East Japan Earthquake)

Report on Field Surveys and Subsequent

http://www.seisvol.kishou.go.jp/eq/kyoshin/jishin/1

Investigations of Building Damage Following the10311_tohokuchiho-taiheiyouoki/index.html

2011 off the Pacific coast of Tohoku Earthquake,13) Japan Society of Seismic Isolation: response

NILIM Technical Note No 674, BRI Building

control building investigation report, 2012

Research Data No 136, 201214) Japan Association for Earthquake Engineering:24) Tatsuya Iwami, Ichiro Hagiwara, Tomohiro Naruse,

Strong Motion data observed at the Fukushima

Ayako Ito: Fire situation at the time of Niigata

Daiichi Nuclear Power Station and Fukushima

Chuetsu Earthquake 2004, Japan Association for

Daini Nuclear Power Station at the Great East

Fire

Japan Earthquake occurred on 11 March 2011,

Conference abstract, pp.340-343, 2005

No.10, 2011

andSafetyEngineering,Research25) Ministry of Construction, Building Research

15) Port and Airport Research Institute, 2011,

Institute: Southern Hyogo Prefecture Earthquake

http://www.eq.pari.go.jp/ (in Japanese).

Damage Survey Interim Report, 1995.

16) Bureau of Port and Harbor, Tokyo Metropolitan
Government, 2011,

3.3.9.5 Measures based on the building damages

http://www.kouwan.metro.tokyo.jp/business/kisojo26) Institute of Industrial science, University of Tokyo:

ho/jishindou.html (in Japanese)

Report of the Building Standards Development

17) Ishihara, K., Muroi, T., and Towhata, I.: In-situ Pore

Promotion Project [40. Study Towards Preparing

Water Pressures and Ground Motions during thethe Construction Standards for Tsunami-hazard

1987 Chiba-toho-oki Earthquake, Soils andAreas] interim report, 2012

Foundations, Vol. 29, No. 4, pp. 75-90, 1989.
18) Architectural

Institute

Recommendations

forof
Designof27) Institute of Industrial Science, University of Tokyo:

Japan:

Report of the Building Standards Development

Building

Promotion Project [40. Study Towards Preparing

Foundations, pp. 61-72, 2001 (in Japanese).

the Construction Standards for Tsunami-hazard19) Arai, H., Hayashi, Y., Inoue, W., Nakai, S., and Iiba,

Areas] second interim report, 2012

M.: A Simplified Method to Estimate Site Effects
Considering
Structural

Soil

Liquefaction,

Performance28) Ministry of Land, Infrastructure, Transport andSymposium

Research

Tourism: Additional knowledge related to theGroupdesign method of safe building structure with253

regards to Tsunami, 201129) National Institute for Land and InfrastructureManagement: Practical Guide on Requirement for
Structural

Designof

TsunamiEvacuation

Buildings (NILIM Technical Note No. 673), 2012
http://www.nilim.go.jp/lab/bcg/siryou/tnn/tnn0673.htm30) Institute of Industrial Science, University of Tokyo:
Report of the Building Standards Development
Promotion Project [40. Study towards Preparing
the Construction Standards for Tsunami-hazard
Areas] Final report, 2012
Websites for reference1) National Research Institute for Earth, Science andDisaster Prevention: Strong motion observation
network (K-NET, KiK-net)
http://www.kyoshin.bosai.go.jp/kyoshin/
2) Japan Meteorological Agency: Strong motion(2011 Great East Japan Earthquake)
http://www.seisvol.kishou.go.jp/eq/kyoshin/jishin/1
10311_tohokuchiho-taiheiyouoki/index.html
3) Port and Airport Research Institute: 2011,
http://www.eq.pari.go.jp/kyosin/
4) Bureau of Port and Harbor, Tokyo Metropolitan
Government: 2011,
http://www.kouwan.metro.tokyo.jp/business/kisojo
ho/jishindou.html
5) National Institute for Land and InfrastructureManagement: Practical Guide on Requirement for
Structural

Designof

TsunamiEvacuation

Buildings (NILIM Technical Note No. 673), 2012
http://www.nilim.go.jp/lab/bcg/siryou/tnn/tnn0673.htm

254

3.3.10 Housing

must keep in mind that these can change over time.

This section gives an overview of human damage
andhousing

relateddamagecaused(1) Overview of the damage to residential property

by thisand the response afterwards

earthquake, which will become the assumption for1) Overview of damage

efforts to be taken in the residential sector, and it also

Extensive areas of land were damaged in the

explains the role played by the National Institute forGreat East Japan Earthquake due to the main shock

Land and Infrastructure Management (NILIM) in theon March 11, 2011, the tsunami disaster, and theefforts for emergency response and recovery in theaftershocks that were centered near the Pacific coast

residential sector. Furthermore, the contents of thisof the Tohoku and Kanto regions. According to reports

section are based on the data and conditions etc. at

published by the National Police Agency (October 31,

the time of writing this document (October 2012). One2012), areas reported to have been affected with

Table 3.3.10.1 Human damage and housing damage in the Great East Japan Earthquake, and housing
conditions thereafter■ The Great East Japan Earthquake Situations of human damage, damage to housing and subsequent residency
Human damage (person)
Number of refugees (person)
Damage to housing (house)
Dead

Missing

Temporary housing,public housing

Total

Complete collapse,
etc.

Half collapse

Total

Subtotal in three prefectures

4,671
9,529
1,606
15,806

1,195
1,359
211
2,765

41,303
113,759
99,229254,291

41,969114,787
99,229255,985

19,21485,45021,094
125,758

5,037
151,736
71,954
228,727

24,251
237,186
93,048354,485

Other prefectures66

4

56,09470,8884,121

37,504

41,625

Total

15,872

2,769

310,385

326,873

129,879

266,231

396,110

Iwate Prefecture
Miyagi Prefecture
Fukushima Prefecture

Note

National Police
Same as on the Reconstruction Same as on the
Agency on October
Agency on October
left
left
31, 2012
4, 2012National Police Agency on
October 31, 2012 (including
washed away and completeor partial loss by fire)

Temporary housing, etc. (house)

National Police
National Police
Agency on October Agency on October
31, 2012
31, 2012(Application of own house)

Construction

Housing rental

Existent public
housing, etc

Iwate Prefecture
Miyagi Prefecture
Fukushima Prefecture

13,98422,095
16,775

3,355
25,00521,967

167
1,055
424

Subtotal in three prefectures

52,85450,327

1,646

48

231

105,106

98,285

Other prefectures
Total

315
53,16912,24562,572

7,249
8,895

921
969

1,283
1,514

22,013
127,119

2,358
100,643

Note

UR

National public
officers’ housing, etc.

Total

Emergency
repair

0
48
0

15
134
82

17,521
48,337
39,2482,767
67,54827,970

Housing Bureau of

Reconstruction

Housing Bureau of

Ministry of Finance on

Ministry of Health,

MLIT on October 1,

Agency on October

MLIT on September

October 28, 2012

Labour and Welfare on

2012 (Number of22, 2012 (Number of24, 2012 (Number ofhouses completed)houses occupied)houses occupied)Same as on the left

Permanent housing
Required number ofhousing (plan)

Iwate Prefecture
Miyagi Prefecture
Fukushima Prefecture
Subtotal in threeprefectures

17,600~18,600
72,000Unfixed89,600~90,600
plus Fukushima’s share

Public housing(plan)

Same as on the left・
results (construction
started)including rebuilding on
its ow n in priv ate
sector, public housing,

Disaster recovery
housing loans

5,600

223

542

15,000Unfixed
20,600

396
230

4,390
1,354

849

6,286

94
943

793
7,079

Housing Bureau of
MLIT on October 31,
2012 (Construction tostart)

Japan Housing
Finance Agency(Tohoku) on
September 30, 2012
(application for use)plus Fukushima’s
share

By October 2012

Note

October 2, 2012

occupied)(Number of applicants)

Note

Other prefectures
Total(Round figures,(Number of houses

Information grasped
by the Housing
Bureau by October
2012

etc.)

255

human damage and damage to housing etc. extend

wide region including inland urban areas, so separate

over 21 prefectures from Hokkaido down to Kochi intotals were prepared for Sendai City, and it was not

the west. The death toll in 12 prefectures totaled toincluded in the totals for other regions of Miyagi

more than 15,000, the missing count more than 2700

prefecture.). The impact of the tsunami caused

people, and more than 99% of these figures pertained

extensive

to the three prefectures of Iwate, Miyagi andPrefectures, and among these the cases of total

Fukushimacollapse (including washed away) seen in Iwate and(hereinafter“3

Disaster-stricken

Prefectures”).

damageinthe3Disaster-stricken

Miyagi prefectures was relatively greater. There wasFurthermore,

130,000

housing

units

were

large number of damaged residences in metropolitan

completely destroyed (of which 126,000 were from the

Sendai, and although there was much damage in the

3 Disaster-stricken Prefectures), the total number ofcoastal regions of Fukushima Prefecture and further

totally and half collapsed housing units was 396,000

south, the damage in the inland regions was also

(354,000 from the 3 Disaster-stricken Prefectures),comparable in magnitude.

and the number of evacuees was 327,000 (these data

Figure 3.3.10.2 compares these damages with thewere from National Police Agency data (housing

Great Hanshin-Awaji Earthquake. Looking at humandamage in terms of number of housing units) anddamage, the Great East Japan Earthquake saw a

Reconstruction Agency data. Table 3.3.10.1 upper

higher death toll compared to the number of injured

section)people, due to the impact of the tsunami. As far as the

Figure 3.3.10.1 is a summary of housing damage indamage to housing was concerned, one can see thatthe six prefectures bordering the Pacific Ocean fromthe two earthquake disasters had almost equivalent

Tohoku to Eastern Kanto, totaled for coastal regions

quantitative damage in terms of number of housing(towns and villages bordering the Pacific Ocean),units damaged (we could not obtain the total number

inland regions (regions other than those mentioned

housing units damaged by the Great Hanshin-Awaji

above), and prefectures (Number of buildings are

Earthquake, so the comparison was effected bytotaled based on data of the Fire and Disaster

substituting the number of housing units with theManagement Agency. Sendai City spreads across anumber of households).
Number of housing units by prefecture and complete or partial destruction incoastal regions

Number of housing units, by prefecture, in coastal or inland regions andcomplete or partial destruction

140000

Number of complete orpartial destruction,
coastal

120000100000

Number of complete orpartial destruction, inland

80000
60000
40000
20000

10000080000

Partial collapse incoastal regions

40000
20000

(2) By prefecture in coastal regions

Figure 3.3.10.1 Number of housing units, by complete or partial destruction

256

Aomori Prefecture

Iwate Prefecture

Miyagi Prefecture (Except Sendai City)

Sendai City

Fukushima Prefecture

Ibaraki Prefecture

Chiba Prefecture(1) By prefecture-wise, by region (coast/inland)

Complete collapse incoastal regions

60000

0

Aomori Prefecture

Iwate Prefecture

Miyagi Prefecture (Except Sendai City)

Sendai City

Fukushima Prefecture

Ibaraki Prefecture

Chiba Prefecture0120000

Number of houses devastated (units)

Number of houses devastated (units)(from Fire and Disaster Management Agency, Headquarters for Disaster Control: Tohoku Pacific Offshore
Earthquake, Report No. 146, (exhibit) (September 28, 2012))
160000(from Fire and Disaster Management Agency, Headquarters for Disaster Control: Tohoku Pacific Offshore
Earthquake, Report No. 146, (exhibit) (September 28, 2012))

Comparison of human damage
60,00050,000Comparison of damages regarding housing

Number of the injured

500,000

Number of missing cases

450,000

Number of the dead

400,000

30,00043,792
2,769

274,181

3

0

6,434
The Great East Japan The Great HanshinAwaji Earthquake
Earthquake (onOctober 31, 2012)(1) Human Damage

265,096

250,000
200,000

200,000

50,00015,8720300,000

266,235

144,274

150,000
100,000

100,000

10,000Complete collapse

350,000

150,000

6,114

20,000Partial collapse

400,000

Complete collapse

300,000
250,000

450,000

Partial collapse

350,000
40,000Comparison of damages to housing(number of units (concerning Great East Japan EQ) andhouseholds (concerning Great Hanshin-Awaji EQ))

186,175

129,391

50,000129,866

0104,906

The Great East Japan The Great Hanshin-Awaji
Earthquake (Number of Earthquake (Number ofhousing units, on
housing units)
September 28, 2012)

The Great East Japan The Great Hanshin-Awaji
Earthquake (Number of Earthquake (Number ofhouses, on October 31,
households)
2012*)(2) Housing damage (No. of(3) Housing damage (No.

housing units/households)of buildings)

Figure 3.3.10.2 Comparison between Great East Japan Earthquake and Great Hanshin-Awaji Earthquake
On

the

other

hand,

in

additiontothe(50,000 units in the 3 Disaster-stricken Prefectures),aforementioned fact that the damage caused by thisand more than half in the two prefectures of Miyagi

earthquake was widespread, depending on the city,and Fukushima are rented. This sort of housing wastown and village, several percent of their population

provided on a large scale outside the 3 Disaster-died, and central management functions of the local

stricken Prefectures (12,000 units “temporary rental,”

government was greatly damaged (13 cities/towns

7,000 units “public housing”), which is assumed towith a death toll of more than 500, of which 4

have received evacuees moving out of the disastercities/towns with a death toll of more than 1000. 6

prefectures (“temporary construction” outside the 3

cities/towns having a death toll that amounted to more

Disaster-stricken Prefectures: 315 housing units).

than 3% of their population, of which 3 cities/towns

Furthermore, another characteristic of this time’s

having this amounting to more than 5% of their

response was that as far as “temporary construction”

population, all data totaled from data published by thewasFire and Disaster Management Agency).

conventional pre-fabricated standardized housing,concerned,

variousprovisions

other

than

such as provision by “house makers,” wooden
2) Emergency measures for housing

construction by local housing builders, etc. wereIn response to such damage, 127,000 housing units

promoted (Table 3.3.10.1, middle section).

(105,000 housing units in the 3 Disaster-stricken

Also, the “emergency repairs” system was widely

Prefectures) were prepared and secured by means ofused for households whose homes suffered damage

emergency housing (emergency temporary housing,to an extent similar to half collapse, and did notetc.), new construction (“temporary construction”),

occupy emergency housing; the total number ofprivate housing rental (“temporary rental”) and the use

applicants was 100,000 (98,000 in the 3 Disaster-of existing public housing or housing for government

strickenPrefectures)

workers. 310,000 (254,000 from the 3 Disaster-

housings+

stricken Prefectures) of the evacuees are residing incomplete/partial destruction” was 57.5%).

(theemergency

ratio

of

“emergency

repairs”

to“casesofthis temporary housing, etc. (Source: Reconstruction
Agency data).

3) Initiatives to secure permanent housing

This time, “temporary rental” (and units treated as

From now on, the securing of permanent housing

temporary construction) was widely used among(self-rebuilding, post-disaster public housing, etc.)

temporary housing, and although it gradually declined

must proceed in an appropriate manner. The required

after the peak period (April-May 2012), at present

numberabout half of the total number, i.e. about 63,000 units

owned/rented housing and public housing is 72,000 in

257

of

housing

units

includingprivatelyMiyagi Prefecture (according to the “Prefectural

disaster (before the earthquake disaster it was 400 –Housing Reconstruction Plan”), and is 17,600 –500 housing units/month, and the pace has gone up

18,600 in Iwate Prefecture (according to the “Basic

to 700-800 housing units/month since the second half

Policy of the Prefectural Housing Reconstruction Plan,”of 2011); however in other prefectures the increasingetc.).

trend is not so clear (Figure 3.3.10.4 (made at the

As far as post-disaster public housing is concerned,

Tohoku branch of the Japan Housing Finance Agency,

the planned number of housing units for Iwate andfrom data published by the Ministry of Land,

Miyagi prefectures is a total 20,600 housing units,

Infrastructure, Transport and Tourism)). There are awhereas no specific number has been given for

cumulative 7,079 cases of “use of disaster recovery

Fukushima Prefecture. The total number of housing

housing loans” from the Japan Housing Finance

units for which construction work has alreadyAgency by the end of September (6,286 in the 3commenced is 943, of which 849 are in the 3

Disaster-stricken Prefectures).
The flow chart of the aforementioned sections 2) –Disaster-stricken Prefectures (as of the end of3) is shown in Figure 3.3.10.3, and the status of theOctober 2012) (Table 3.3.10.1, lower section).

efforts

The present state of self-rebuilding is such that in(quantitative)

taken

for

damages

emergency measures is shown in Table 3.3.10.1.

Miyagi prefecture, the number of privately-ownedhouses for which construction work has commenced
is somewhat greater than that before the earthquake■ Image of a flow from disaster/evacuation to securing permanent housing
FormerDisaster

Immediate aftermathof the disasterA few weeks to months after the disasterA few months to years
after the disaster

Securing permanent
housing

Former own house

Improvement
works, etc.

Improvement
works, etc.

Private rental houses treated as emergency
temporary housing (temporary rental)

Former own
house

Disaster
Emergency temporary housing(temporary construction)

Self-rebuilding

Safety, etc.
Existing public housing, etc. (including
officials’ residences, etc.)

Post-disaster public
housing
Secondarysafety (Japanese
inns, hotels, etc.)

Figure 3.3.10.3 Flow from disaster/evacuation to securing permanent housing (image)

258

and

March 2011

700 – 800 houses

Process of number of housing units on which construction work started）
in the 3 Disaster-stricken Prefectures (owner-occupied housing)Houses
1,000

Iwate
Prefecture900

MiyagiPrefecture

Fukushima
Prefecture

MiyagiPrefecture

400 – 500 houses

800
700
600

Fukushima
Prefecture

500
400

Iwate
Prefecture

300
200
100
0
April

June August

FY2007

December
April
October
February

June August

FY2008[Number of houses started in
FY2007]
Iwate Prefecture→3,571
Miyagi Prefecture→5,388
Fukushima Prefecture→6,283

December
April
October
February

June August

FY2009[Number of houses started in
FY2008]Iwate Prefecture→3,453
Miyagi Prefecture→5,416
Fukushima Prefecture→6,010

December
April
October
February

June August

FY2010[Number of houses started in
FY2009]Iwate Prefecture→3,086
Miyagi Prefecture→4,742
Fukushima Prefecture→5,220

December
April
October
February

June August

FY2011[Number of houses started in
FY2010]
Iwate Prefecture→3,278
Miyagi Prefecture→5,599
Fukushima Prefecture→5,190

December
April
October
February

June

August

FY2012[Number of houses started in
FY2011]
Iwate Prefecture→3,405
Miyagi Prefecture→7,553
Fukushima Prefecture→5,162

Figure 3.3.10.4 Number of housing units on which construction work started in the 3 Disaster-stricken
Prefectures (privately-owned)(2) Survey and technical support by NILIM

dispatched personnel to carry out guidance and

The actual condition survey and technical support

coordination for smooth provision of emergency

related to main bodies (local public bodies and/or

temporary

housing

related agencies including private) of the efforts in the

Prefectures.

NILIM

aforementioned process (Figure-3.3.10.3) are central

cooperated with the session for study/preparation of

to the efforts of NILIM in the residential sector. The

the “Emergency Temporary Housing Construction

outlines of each stage are as follows.

Manual (Interim Report)” (May 2012) organized by

in

the

also

3

Disaster-stricken

participated

in

and

MLIT, which was done in coordination with the1) The survey of emergency housing and efforts ofRegional Development Bureau of MLIT, the local

housing builders etc. after the disastergovernments, and associations of related industry,An actual condition survey on the efforts of local

based on the series of experiences surrounding the

housing builders and distributors of building materials

planning and construction of emergency temporary(lumbers,

housing.

timbersetc.)

tosecurehousing(rebuilding/repairs of housing, etc.) on site was carried

There was huge damage by the earthquake andout mainly in tsunami-devastated areas since May

tsunami disaster in the devastated areas including 3

after the disaster (still continuing now).

Disaster-stricken Prefectures; there was a power

The following dotted line box is from results of the

failure immediately after the disaster, gas and waterinterview survey (survey period: June, September andsupplyNovember 2011, Survey target: 15 small housing

temporarily

builders etc. in Iwate and Miyagi prefectures)material workshops located in the coastal regions

conducted by NILIM, to show the general trend related

were damaged by the tsunami, resulting into recovery and reconstruction activity being carried

shortages of some materials and equipment

out since immediately after the earthquake disaster by(plywood, heat insulating materials, roofing tile

such companies.

material, etc.). In such a situation, local housing

Moreover, a survey about temporary housingbuilders

matters was carried out as part of the above project.

halted,andfailed.

revivedtelephoneservices

Furthermore,construction

also

construction

activity,

movingtowards recovery and reconstruction in the region.

And in June 2011, following a request by MLIT, NILIM

259

from outside the region.

While the restoration of lifelines had still not

NILIM, along with the Building Research Institute,progressed in a large part of the disaster areas,
immediately after the main shock, local housing

providedbuilders,ofparticipated in the studying processes of the “Regionalbuildings and housing their companies had built,

Recovery Housing Coordination Committee,” whichand carried out emergency repairs as required andwas the promoting parent organization, and taking

started their activities. Full-fledged restoration

over from this the “Regional Recovery Housing

activities began after telephone lines were restored,

Promotion Committee” of each prefecture.

conducted

temporaryinspections

The

but even after that, movement and activities were

supportinaforementioned

technical

aspects,“Coordination

andCommittee”

restricted due to gasoline shortages and shortages

started in September 2011 with the cooperation ofof heat insulating material etc. due to therelated public and private bodies in the 3 Disaster-earthquake disaster. Activities by local housing

stricken Prefectures. It prepared the “Design andbuilders began at levels that were manageable by

Building System Guidelines” in December 2011.

themselves, and it transitioned over time to

Various model design samples, including examples of

becoming full-fledged maintenance and repair work

the utilization of post-disaster public housing, thewith the disappearance of shortages of gasoline

scheme for method of construction/design that takes

and materials.

the topography and costs reduction into consideration,

Relatively large scale repair work by local

were being posted for each region, wherein “Regional

housing builders began one month after the

Recovery Housing” was defined as “housing units that

occurrence of the earthquake disaster, about mid-

fit into the concept comprising 6 items (long-term use,

April when the method for the distribution of theenvironment-responsive, low-cost, etc.), built on the

donation money to each prefecture was decided on.

basis of the design plan for conventional wooden

Looking at the example of Miyako City in Iwate

housing units and the building system for ensuring

prefecture, subsidies for house remodeling thatsmooth supply which can handle a demand far

were being implemented before the earthquake

exceeding that during normal times.” Furthermore,disaster were put to use, and moves were also

proposals that take into consideration the utilization ofseen to allocate these to expenses for maintenance“Disaster Recovery Housing Loans” (mentioned

and repair work. Recently, some movement isearlier) of the Japan Housing Finance Agency or thebeing“Regional Housing Branding Project” of MLIT (aid for

seen

in

residential

reconstruction(reconstruction/ new construction), but the local

long-term

housing builders mainly continue to receive apracticing the regional housing production system)

considerable number of orders pertaining tohavemaintenance and repair work even now.

Committee was reorganized in February 2012, and a

also

good
been

housingputby producers’
forth.

The

groupsCoordination“Regional Recovery Housing Promotion Committee”
2) Support to the efforts for “Regional Recovery

was established in each of the 3 Disaster-stricken

Housing”

Prefectures; and their promotion was promoted with

“Regional Recovery Housing” is an initiative on partthe recruitment/ registration of housing productionof local housing builders and suppliers. It is estimatedgroups (consisting of the architect offices, housingthat the housing demand arising in the disaster areasbuilder offices, material distributors for materials likehereafter would far exceed the housing demand

lumber, etc.) that provide housing in accordance withvolume in the pre-disaster period (normal times), andthe “guidelines” (the number of registered groups in

it is necessary to effectively utilize the material andMay 2012 was Iwate 136, Miyagi 76, Fukushima 90)

production capacity of local housing builders while(see Figures 3.3.10.5 to 6).

also promoting, as required, the use of the capacity

Hereafter, along with making use of the various

and cooperation of housing builders and suppliers

support measures being adopted, it is desirable to260

conduct PR in such a way that the advantages and6 concepts

Design and production system

Longterm use

Designmerits of “Regional Recovery Housing” are easy forthe disaster victims to understand, and to reinforce apractical coordination system for each of the

Futuregrowthproduction groups that would respond to the

Cost
reduction

Demandcorrespondence
Conceptincreasing demand.
Local
conformity

Environmental
response

Moreover, although not explained in detail here, inMaterial
procurement

Low
price

addition to “Regional Recovery Housing” initiatives, aDesign andproduction
systemProcess
control

Builder
supportOperation
andmaintenancevariety of initiatives are being promoted related tohome-providingbyhousingbuilders/

Figure 3.3.10.6 Regional Recovery Housing “6suppliers

Concepts” and “Planning and Production System”(building contractors, material distributors for materials
like lumber, etc.) in the region; some of these
initiatives started earlier, and some took root after the3) Support for development of post-disaster public

earthquake disaster. Hereafter, it is expected that we

housing

focus on such activities in response to the housing

Post-disaster public housing is another importantdemand that is getting more and more acute day-by-

aspect for the securing of permanent housing; a

day and town/city rehabilitation.

supply that responds to the various demands of theregion to ensure residential stability for victims isneeded. In a general disaster, the local public bodyprovides post-disaster public housing (**) to a victim
who has lost his home in the disaster and has income
at or below the standard (*); however, in the case of
the recent earthquake disaster, under the Great East
Japan Earthquake Recovery Special District Act,
special measures are established related to therequirements for occupying housing units, such as
abolishing the income prerequisite during a certain
period (maximum 10 years) after the occurrence ofthe disaster.
(*) Depends on the regulations of the local public
body.
(**)

As

methodsofprovision,

there

are

“construction,” “purchase” and “rent”).
Furthermore, in an effort to promote quick andefficient provisions by the local public body of thedisaster-struck

region,MLIT(Housing

Bureau)conducted a “Study on Methods of Planning and
Figure 3.3.10.5 Production/Promotion System for

Providing Post-disaster Public Housing” (FY2011 third

Regional Recovery Housing

supplementary budget). The objective of this study is
to conduct, in the form of a study under the directcontrol of the ministry, a study of the basic plan for
housing developments, the master provision plan
usually carried out by the local public body for thosecities, towns and villages in regions which request thisand which are covered by the Act on Special Financial261

Support to Deal with the Designated Disaster of

implementation experience.

Extreme Severity, and to extensively provide its

The

study

on

the

basic

plan

for

housing

results to local public bodies of disaster regions.

developments etc. for cities/towns/villages which

NILIM accepted a request by the ministry, carried out

made a new request was conducted also in FY2012,technical support for the coordination of results basedand NILIM participated in the study as it did in FY2011.

on exchange of opinions and coordination of the study,

Furthermore, in theme-wise studies by the Housing

and put forth a practically feasible proposal with highBureau, studies on the subjects of community/elderly

effectiveness along with BRI, cooperating with many

population,other bodies concerned in addition to towns and cities,

management, etc. were conducted, and their results

the 3 Disaster-stricken Prefectures, and related

were used in the planning studies in each region (seeorganizations (UR, other ministries and agencies,

Fig. 3.3.10.8).

disasterprevention

andcrisislocal agencies, etc.) (Figure 3.3.10.7).

System and contents for technical support
Housing Orders
SurveySurveyBureau of Reports consultants
MLIT

Information
supplyPolicyadjustment

Work
instruction

Iwate Prefecture
MiyagiPrefecture
Fukushima
PrefecturePlanadjustment

33 local＋ ingovernments
devastatedareas
Grasp of intention
Field survey

National Institute for Land and Infrastructure Management, Building
Research Institute
Applying the accumulation of such knowledge and experience regarding: national housing policy and local housing policy and plan, etc.
: housing reconstruction during disasters in the past
: lifelong duration of housing and housing production system

Figure 3.3.10.7 Study framework and role of NILIM in

Figure 3.3.10.8 “Study on Methods of Planning and“Study on Techniques of Planning and Providing Post-

Providing Post-disaster Public Housing” study

disaster Public Housing”

examples from the point of view of elderly
people/community formation

The survey consists of a region-wise study and atheme-wise study; the former was conducted in 33(3) Conclusion

cities/towns/villages (Iwate 9, Miyagi 16, Fukushima 8).

The aforementioned description gave an overview

It offers proposals for the various types of housingof human damage and the damage to housing caused

units and housing estates adopting various types ofby this earthquake and tsunami disaster, whichconstruction such as low-rise wooden structure,

becomes the basic postulate of the efforts to be taken

medium and high-rise RC, and for introducing various

in the residential sector, and it also explained the role

functions for residences of elderly people, in a format

of NILIM in the efforts for emergency response andto respond to each of the region’s situations and policy,

recovery in the residential sector.

taking into consideration the safety for tsunamis,

The important points to be noted about the issues

topographical characteristics of the region etc.

and initiatives in the housing sector in the disaster

Moreover, measures for widespread promotion wereareas are now changing over to appropriate securing

proposed and implemented depending on the presentof permanent housing (self-rebuilding, post-disastersituation of each region, as a model study aboutpublic housing, etc.), but it is necessary to pushlandscape formation for post-disaster public housing,

forward with residential development, while working toand preparation/distribution of system/ technicalmaintain consistency with urban development andreference materials regarding post-disaster public

regional development based on a long term and broad

housing for cities/towns/villages that have little project

perspective. Many issues remain, such as obtaining262

1, 2012), 2012

land, production and supply systems, providing
various information to victims, adequate support by

8) Ministry of Land, Infrastructure, Transport andthe public side, etc. We continue to pray for the fastest

Tourism (Housing Bureau): Status of the numbers

possible recovery of the disaster areas.

of units of Publicly-Operated Housing, UR rental
housing, etc. possible to be contributed to thevictims, and which are already occupied, 2012

Acknowledgements
We wish to express our deepest gratitude towards9) Ministry of Land, Infrastructure, Transport andthe “Regional Recovery Housing Promotion Group,”

Tourism, (Housing Bureau): [FY2011 Housing

the Tohoku Branch of the Japan Housing FinanceConstruction Projects Survey] Results of the study

Agency, and all other related people who provided us

work on the planning and supply methods forwith the data used in this document.

post-disaster public housing, 201210) Ministry of Finance: Actual results in provision ofReferences

national property in the Great East Japan

1) National Institute for Land and Infrastructure

Earthquake, 1. National Public Officers’ Housing(as of September 28), 2012Management, Building Research Institute: Quick
Report of the Field Survey and Research on “The11) Reconstruction Agency: Number of occupied

2011 off the Pacific Coast of Tohoku Earthquake”

housing units of emergency temporary housing by(the Great East Japan Earthquake), TECHNICAL

renting private rental housing (October 22, 2012),

NOTE (NILIM) No. 636 / Building Research Data

201212) Reconstruction Agency: Number of evacuees etc.

(BRI) No.132, 2011

nationwide (October 10, 2012), 2012

2) National Institute for Land and Infrastructure13) Reconstruction Agency: Status and initiatives ofManagement, Building Research Institute: Reportreconstruction (October 16, 2012), 2012

on Field Survey and Subsequent Investigations of14) Regional

Building Damage Following the 2011 off the

Recovery

Housing

Coordination

Earthquake,Committee in the 3 Disaster-stricken Prefectures

TECHNICAL NOTE (NILIM) No. 674 / Building(Iwate, Miyagi, Fukushima): Regional Recovery

Research Data (BRI) No. 136, 2012

Housing Design and Building System Guidelines,

Pacific

Coastof

Tohoku20113) Ryo Otake: Reconstructing homes in disasterregions: challenges and support (NILIM 2012:

Useful reference websites

NILIM Report 2012 No. 11), 2012

1) Regional Recovery Housing Promotion Group4) Fumitake Meno: Current status and issues ofproviding housing to disaster victims (Building

Iwate

Research Institute lecture (FY2011) text), 2012www.hukkoujuutaku.sakura.ne.jp

5) National

PoliceAgency,Headquarters

Miyagi Prefecture: www.hukkoujutaku.com

forEmergency Disaster Control: Status of damage

Fukushima

due to the 2011 Tohoku Pacific Offshore

hukkoujuutaku.org

fukushima-

page on Great East Japan Earthquake:2012), 2012
andPrefecture:2) Japan Housing Finance Agency, special web

Earthquake and Police measures (October 31,
6) FirePrefecture:

DisasterManagement

Agency,http://www.jhf.go.jp/shinsai/index.html

Headquarters for Disaster Control: 2011 Tohoku

3) Building Research Institute, Special page on

Pacific Offshore Earthquake, Report No. 146,

Tohoku Pacific Offshore Earthquake:

Exhibit (September 28, 2012), 2012www.kenken.go.jp/japanese/contents/topics/2011

7) Ministry of Land, Infrastructure, Transport and0311/index.html

Tourism (Housing Bureau): Emergency temporary
housing starts and completion situation (October263

3.3.11 Cities and Towns

inundation height.

3.3.11.1 Damage situation of built up areas③ The third report “The fact-finding results of the(1) Findings such as damage situations in the built up

refuge from tsunami” (quick report) (December 26,

areas suffering from the tsunami based on the2011, publication)

examination and investigation study on the revival･The persons who started the refuge action before thetechniques 1) (by City Bureau, MLIT)

tsunami came after the earthquake was generated

The City Bureau carried out the examination andare approximately 63% of the whole.

investigation of revival techniques for built up areas･Whereas the actions for the preparation for refuge

suffering from the tsunami using the first revised

from the tsunami or for the refuge itself were frequent

budget in 2011, and performed a study of the damage

immediately after the earthquake occurrence, there

situations that was necessary to support the local

were also many actions for the search of their family

governments for revival, where their power was cut formembers, relatives and acquaintances as well as forthe restoration measures.

the checking of the damage situations.

The findings were announced (as quick reports)･The refugees by foot and those by car were almost

sequentially after August 2011, and their main

half-and-half, but for younger generations, the ratio ofcontents were as follows.

car evacuation was higher.

① "Findings of the present damage situations by the

These results of this investigation on the tsunami

Great East Japan Earthquake" (the First report)

damage(August 4, 2011, publication)

governments, and the main aggregate data were2

situations

wereprovided

to

local

･The inundation area is about 535km , in which more

shown on the homepage of Ministry of Land,

than 40% has an inundation height above 2m, andInfrastructure, Transport and Tourism.

thenumberofthesufferingbuildings

isapproximately 220,000, of which approximately(2) Analysis about the suffering situations of the built

120,000 buildings are completely destroyed which

up area

includes being washed away.

The NILIM in cooperation with the Building･There is a large difference in the relation between the

Research

inundation heights and building suffering situations at

Agency, Japan) summarized the results of the survey

around 2m of the former, namely; the percentage ofand study on the damage to buildings and so on ascompletely destroyed buildings were predominant in

the “Report on Field Survey and Subsequent

areas where inundation heights exceeded 2m.

Investigations of Building Damage Following the 2011

② The second report (October 4, 2011 publication)

off the Pacific coast of Tohoku Earthquake 2)” in･According to the number of building floors based on

March 2012.

Institute(Incorporated

Administrative

the study of the relation between the inundation

The summaries of the report on the analysis on theheight and the building suffering situations, in thedamage situations of the built up areas that NILIM

case of a three-story building or higher, such as

was in charge of were as follows.

reinforced concrete constructions, the ratio ofdestruction danger is low when persons are above

1) Comparison of the damage of the built up areas

the inundated floor and the inundation height iswith those the past great earthquakes and otherconsiderably lower than the building height.

disasters･ Concerning the relation between the inundation

Concerning the scale of the built up areas thatheight caused by the tsunami and the humanreceived tsunami inundation by the Great East Japan

damage, the ratio of dead persons of 65 years or

Earthquake disaster and that of the reconstructionolder

sufferingprojects estimated in the future, we performed thecommunities, and it accounts for the majority of thecomparison with the main disasters in the urban area

dead. In addition, the death rate rises with theof our country after the 20th century.

exceeds

that

of

the

whole

264

Table 3.3.11.1 Scales of the damages of main urban

Table 3.3.11.2 Damage divisions that take thedisasters and post-disaster reconstruction projects

maximum value in each mesh

Disaster name
The Great Kanto
Earthquake

Damages by the
Pacific War
Isewan Typhoon

The Great
Hanshin-Awaji
Earthquake
The Great East Japan
Earthquake

Main disaster types
Fire in an urban area

Fire by air raids

Areas burned out
and inundated

Devastated cityOne
metropolitan
prefecture
and 6
prefectures
215 cities

Tokyo City
Yokohama
City

About 3,470ha
About 924ha

3 Prefectures Iwate Prefecture Miyagi Prefecture Fukushima Prefecture

Post-disasterreconstruction
project area
About 3,600ha
About 358ha

Number of
Number of
Number of
Number of
Proportion
Proportion
Proportion
Proportion
meshesmeshesmeshesmeshes1,532 39.7% 500 13.0% 789 20.5% 243 6.3%
282 7.3% 37 1.0% 218 5.7% 27 0.7%
Complete destruction (Inundation on 1st
floor’s ceiling or more)
112 2.9% 45 1.2% 41 1.1% 26 0.7%
Large-scale partial destruction
301 7.8% 53 1.4% 221 5.7% 27 0.7%
Partial destruction (inundation above
floor level)363 9.4% 56 1.5% 215 5.6% 92 2.4%
Partial loss (inundation below floor level) 304
7.9% 27 0.7% 208 5.4% 69 1.8%
No damage927 24.0%
0 0.0% 89 2.3% 838 21.7%
Unknown or not surveyed
35 0.9%
9 0.2%
0 0.0% 26 0.7%
Total
3,856 100.0% 727 18.9% 1,781 46.2% 1,348 35.0%
Complete destruction (washed away)
Complete destruction

About 64,500ha

High tide (inundation)

21 prefectures and 570
local governments

About 18,540ha

Fire in an urban area

2 prefectures and 25 cities
and towns

About 63ha

Inundation damage
by a tsunami
Inundation damage
area (partial collapse
or more)Fire by tsunami

7 prefectures and 190 local
governments (including thetsunami devastation of 6
prefectures and 62 local
governments)

About 53,500ha

102 cities
About 28,200ha－(focusing on
temporary housing
and infrastructure
restoration)
20 districts
About 265ha
UnfixedAbout 15,700ha② The complete destruction rate in mesh

About 65ha

In three prefectures, mesh completely destroyed
2) The building damages caused by the tsunami

rate over 80% exceeds 40% of the total. Though theWe created an original database by building unit on

meshes with a high rate of complete destruction were

the basis of the surveys of “Building damage situation”

mostly near shorelines, and the influence of theand “Height of the inundation by the tsunami” in thetsunami run-up river was also observed.

abovementioned “Survey of the damage situation by
Tsunami” by the City Bureau of MLIT, and wesummed this up by prefecture’s boundary and by a
～100%
1536

500m mesh unit and then analyzed it. (Based on the

～20%
1814

survey data at the end of November 2011)
Layer of areas
inundated by tsunami(100m meshes)

500m mesh layer

Inundation depth

Mesh codes

Layer of devastationsurveyed buildings
For
analysis～80% ～60%～40%
226 166
114

Figure 3.3.11.2 Complete destruction rate in each

DB compilation
only with attributeinformation

mesh
Aggregate bymesh code

Chart bymesh

③ Relations between the tsunami inundation height

Data bymesh

and the damage
In the relations between the inundation height andFigure 3.3.11.1 Analysis image of building damages

the complete destruction rate, a great difference iscaused by the tsunami

observed at inundation heights of 3m or less andmore than 3m. More detailed analysis is required
concerning influences such as the topography.

The summaries of the analysis are as follows.
① The maximum damage levels in the meshes
When we add up the values in the meshes ofdamage levels that take the maximum, the total of the
top three prefectures occupies about half of thecomplete destruction by three divisions. The ratio of
the meshes that take the maximum of damage
divisions more than that of partial destruction differs
depending on prefectures.

265

Average tsunami inundation depth in mesh (m)3.3.11.2 Restoration and the revival of suffering
Entire226166
114

1536

1814

community areas

12m～

68

0
212

～12m

110

0
4 11

～100%
～80%

techniques for the community areas suffering from the1
16 4 17～60%

tsunami. (City Bureau)1)

～09m

309

～06m

576

～03m

69

101
135126

473
0%

20%

(1)

～40%

34
1237

60%

and

surveysontherevivalThe City Bureau performed the examination of the～20%

types of community area revival patterns in order to

1757
40%

Investigation

80%

contribute to the realization of recovery policy in the100%

built up areas of local government such as ① theComplete destruction rate in mesh

Figure 3.3.11.3 Relations of the tsunami inundation

investigation and classification of the types of theheight and complete destruction rate

reconstruction projects according to the damage
situations and the community characteristics, and ②

3) The number of refugees and the restoration

the study of revival methods appropriate for thesituation of the lifelines

patterns of reconstruction of the built up areas.
The report of the investigation was performed as

As a whole, the tendency of a decrease in thefollows.

number of the refugees with the restoration of thelifeline was seen in case of the Mid Niigata prefecture1) Examination and investigation of the built up area

Earthquake in 2004.

revival patterns

However, for the present earthquake, we cannot
read clear relations between the lifeline restoration

Based on findings such as the tsunami sufferingand the decrease of refugees in Iwate and Fukushimasituations, the City Bureau examined the built up area

prefectures. In Miyagi prefecture, the number ofrevival patterns depending on the damage situations,refuge households was decreased with the restorationand the community characteristics and the local

of electric power until the end of March, however theintentions, made basic materials for examination of

number of refuge households hardly decreased after

such matters as the revival technique and supported

late March, even though the waterworks and city gas

the decision of revival plans by the suffering local

were restored.

governments.

As for this factor, it is thought that a large number of

The investigation summary documents of every city,

houses were damaged by this earthquake and it was

town and village became accessible on the homepage

impossible to come back to the homes in suchof the MLIT.

situation even if the lifeline was restored.
2) Correspondence scheme to the policy problems
which are common to the tsunami stricken areas

Number of households and houses

1600000
1400000

Estimated number of evacuated households inthe whole of Miyagi Prefecture
Number of houses lost power

1200000

Number of houses stopped water

1000000

Number of houses stopped supplying city gas

The following examination and investigation werecarried out concerning the policies for the common
problems in the stricken areas, and the “Investigation

800000of the tsunami suffering built up area revival

600000techniques (Conclusion)” was published on April 24,

4000002012. In addition, the individual findings of ① to ⑤

2000000
3/11

as well as the detailed data of ⑥ were released.
3/18

3/25

4/1

4/8

4/15

4/22

4/29

① Studies of the improvement of parks and afforested

5/6

Figure 3.3.11.4 Relations of the estimated number ofareas relevant to the recovery from the Great East

the refuge households and the lifeline restoration

Japan Earthquake disaster: “The technical guidance

situation (Miyagi prefecture)

about the improvement of parks and afforested area”(March 27, 2012, publication)266

② The investigation of the utilization of debris forsupporting system, and the second part describes thequick recovery and restoration; “A fundamental

methods for how to grasp the suffering situation andconcept of the utilization of reproduction materials to

the geological survey.
The survey continued in 2012, and an investigation

residential land development laying, contributing toquickrestoration,

revival”(March27,

was carried out, and it was published4) coauthored by

2012,

publication)

the NILIM likewise in August, and “effect, influence③ Investigation and survey of concepts of planningfacility calculation seat” (trial version) for liquefaction

and designing of the urban spaces: “Fundamentalof the ground control in an area “of the ground-water

concepts of making the landscape and urban spaces

level lowering” was utilized for actual examination of

for the revival” (April 19, 2012, publication)

the anti soil liquefaction measures in the suffering built④ Investigation for the inheritance of historical andup areas.

cultural heritages in the revival projects: “Fundamental
concepts of urban area recovery by utilizing the(3) Residential land anti soil liquefaction measures

historical and cultural heritages” (April 24, 2012,

utilizing the construction technology and research

publication)

development⑤

Investigation

for

the

maintenance

for

the

community

policies,

system(Minister's

secretariat, MLIT)

and

Utilizing the construction technology research

management of local community in the revival state:“Guidelines

furtherance

development

thefurtherance system,theminister’s

collaboration of measures for health, medical care andsecretariat called for proposals for technology andwelfares as well as the community formation after the

research developments with the problem themes ofGreat East Japan Earthquake disaster” (April 24, 2012,“The technology and research development on

publication)

economical

andefficient

anti

soil

liquefaction⑥ Affairs concerning the construction of consensus

measures in existing public facilities and residential

formation support tools in the interactive community

areas” in the 2011 supplementary budget and “Therecovery process.

technology and research development for more

⑦ Affairs concerning the location of evacuation routes

economical and precise prediction of liquefaction

and refuge facilities as well as refuge guidance.

disasters” in the 2012 budget.

⑧ Investigation affairs concerning reconstructing local
industries

and,broad-based

production

As a result, ten problem themes were adopted,
respectively, and the furtherance to technology

anddevelopment was being carried out.

distribution functions in the stricken areas.

NILIM joined in the adoption process.
(2) Integral anti soil liquefaction measures for public(4) Arrangement of correspondences such as the risk

facilities and residential areas in the damaged areas

judgment of damaged residential lands and theUsing the 2011 supplementary budget, the City

construction building restrictions (NILIM)

Bureau performed the survey of safer and lower-costConcerning

anti soil liquefaction measures for building up the

the

risk

judgmentofdamagedprojects to promote and to advance integral anti soil

residential lands and the building restrictions, theliquefaction measures. The survey was performed inoutlines of the correspondences by MLIT or local

cooperation with the NILIM and its achievements weregovernments that the NILIM rearranged in the “Reportpublished as the “Study and survey for the revival of

on Field Survey and Subsequent Investigations of

the built up areas suffering from liquefaction by the

Building Damage Following the 2011 off the PacificGreat East Japan Earthquake disaster: (Guidancecoast of Tohoku Earthquake”2) are as follows.

[plan])3)” coauthored by the NILIM in April 2012. The
first part summarizes the flow of rebuilding of1) Post-earthquake quick inspection of damaged

liquefaction-damaged

residential lands

built

up

areas

and

the

267

According to a publication document by the MLIT

disaster danger district codes were established, anddated January 10, 2012, inspection was conducted on

areas partially designated.

the damaged level of residential land in 56 cities,
towns and villages in 9 prefectures, and in 6,456

3.3.11.3 Action of residential land anti soil liquefaction

places of investigation points, 1,450 places were

measures in the damaged built up areas

judged “unsafe” and 2,142 were “limited entry.”(1) Liquefaction analysis of the suffering blocks by
three-dimensional FEM

Table 3.3.11.3 Result of post-earthquake quick

The NILIM examined the effect of integral anti soil

inspection of the damaged residential lands (byliquefaction

prefecture)by prefecture

Danger (red)Caution(yellow)measuresofpublicfacilities

andresidential areas based on the combination of plural
Surveyed(green)methods of construction at the liquefaction-stricken

Total

areas as a model case of the Great East Japan

Iwate Prefecture
Miyagi Prefecture

Earthquake disaster by computer analysis using the

Fukushima Prefecture

2011 supplementary budget.

Ibaraki Prefecture
Tochigi Prefecture

The result was used as examination materials

Gunma Prefecture

about effective methods of construction to control the

Saitama Prefecture

re-liquefaction

Chiba Prefecture
Niigata Prefecture

in

the

suffering

built

up

areas

performed by MLIT.

Total

The procedures of the examination are as follows.
① Setup and adjustment of the ground model (before

2) The implementation progress of the building andthe measures)

urban planning restrictions (as of the end of January

We built the present ground on a computer and2012)

simulated the liquefaction behavior for the seismic① Iwate prefecture

wave of the Great East Japan Earthquake disaster.
② Setup of the ground model and earthquake

The construction restrictions with compelling force
are not enforced, while the self-restraint in the building

response analysis (after the measures)

activity is requested by the local governments in someWe set the state that is expected on the basis of theinundation areas (Miyako-city and Kamaishi-city).

present ground model and analyzed the effect of the② Miyagi prefectureliquefaction restraint against the seismic wave.

・2 months after the earthquake: 4 cities and 2 towns③ Presentation of the analysis results

partially designated asbuilding restricted areas

We analyzed the effect of anti soil liquefaction

according to Article 84 of the Building Standard Law.

measures according to the intercomparison by the・6 months after the earthquake: 4 cities and 3 towns

combinations of having anti soil liquefaction measures

were partially designated as building restricted

or not as well as of the countermeasure methods ofareas by the Special Provisions of the Building

construction.

Restrictions Law.

For example, concerning countermeasures in・8 months after the earthquake: 4 cities and 3 towns

adjacent

were partially designated by the law.

residential

areas,

we

confirmed

theapplicability of reproducing such transformations of・After 8 months or more after the eathquake: 4 cities

the ground where buildings next to each other are

and 2 towns were partially designated as damaged

seen to bow as observed in many locations in thebuilt up area revival promotion areas, and in 1 cityliquefaction stricken areas, we quantitatively analyzed

and 1 town, disaster danger district codes were

the difference of the effects by the independent

established and areas partially designated.

measures based on the ground water level lowering③ Fukushima prefecture

method and by the combination of basement water

In Soma-city, Minamisoma-city and Shinchi-machi,

level lowering and excess pore water pressure268

dispersion methods with drain pipes, and calculated in
combination the effect of the synergy of the measures(2)

Full-scale

vibration

experiments

forof the road part and the residential area part andcountermeasures against residential land liquefaction

various measure mechanics.

(Measurement of the effective range of the drainage
off method with a drain pipe)

Outline of modeling of drain parts
0.5m × 2 elements = 1m

The NILIM made measurements of the depression

0.5m × 2 elements = 1m

effect and the range (namely, the horizontal distance

Modelling by plane strain

Roadsfrom the diameter center of the drain pipe) with the

Buildings

water pressure dispersion method using drain pipes todetermine items such as coefficients to use for

Current groundwater levelcomputer analysis of the design method of integral

As1 (liquefied layers)

Planned groundwater levelAc1

anti soil liquefaction measures for public facilities andAc2

residential areas using the supplementary budget in
2011.

Crushed stones

Figure 3.3.11.5 Placements of calculation meshes
and measure constructions
Settlement←Vertical displacement [cm]→Uplift

At the end of the main shock

About 29 minutes after the main shock
After the surplus gap water pressure
dispersion

At the end of aftershocks

5
0
-5
-10
-15
-20
-25

-15

-10

-5

0

5

10

15

Horizontal distance from housing lot borders [m]At the end of the main shock
At the end of aftershocks

About 29 minutes after the main shock
After the surplus gap water pressure
dispersion

Photo 3.3.11.1 Appearance of the test body ground

5
0
-5
-10
-20
-25

-15

-10

-5

0

5

10

15

Horizontal distance from housing lot borders [m]

1500

4- 7

3- 8

3- 7

GL.-1.55m

4- 1

3- 5

Porous PVC tube
φ50mm
D2

Porous PVC tube
φ100mm
D1

4- 3

4- 4

3- 4

3- 3

2- 1

C- 1

1- 8

1- 7

2- 3 2- 4

1- 4

1- 3

100

E- 2

100 300 500

f4
f5

1- 1

E- 1

1- 2

W-2

500 300 100 100

1- 5
1- 6

2- 2

3- 2
W-3

100 100 300 500

2- 8

2- 6

Liquefied layer

3- 1

2- 7

f6
f7

W-1
500 300 100 100

f8
f9
f 10
f 11

Non-liquefied layer(firm ground)

f 12
f 13
f 14

5

f 15

0

Shaking table

-5

10000

-10
-15

Figure 3.3.11.9 Placements of the drain pipe and

-20
-25

f1
f2

2- 5

C- 2

3- 6

W-4

5000
About 29 minutes after the main shock
After the surplus gap water pressure
dispersion

4- 8

4- 6

4- 2

3000

At the end of aftershocks

CenterResin string tube (Non-measured
φ50mm
parts)
D3
C

Resin string tube
φ100mm
GL. ±0m
D4
WL.-0.3m
4- 5

countermeasure (groundwater level lowering method)
At the end of the main shock

SWS test
Subsidence measuring position

Shaking direction

f3

Figure 3.3.11.7 Independent effects of theSettlement←Vertical displacement [cm]→Uplift[Side view]

Accelerograph and hydraulic gauge
Hydraulic gauge
Soil moisture meter
Displacement gauge-15

300 200

Settlement←Vertical displacement [cm]→Uplift

Figure 3.3.11.6 Reappearance of the recent situations

sensors in test body ground
-15

-10

-5
0
5
10
Horizontal distance from housing lot borders [m]15

Figure 3.3.11.8 Compound effects of thecountermeasure (groundwater level lowering methodand drain pipe)

269

f 16

Resin string tube

Resin string tube

Porous PVC tube

Porous PVC tube

this measure by inputting the ground survey data ofeach district and the assumed earthquake scales forthe evaluation and publication of them and to allow
anyone including the local governments of the strickenarea to download and use them.

Figure 3.3.11.10 Distribution of the excess pore water

The public offer of the calculation sheets ispressure ratio

described on the homepage of the NILIM as
Technology Breaking News No. 2.4)

It was confirmed that the liquefaction depression
effect of drain pipes had influences on the seismic(4) The FEM analysis of the liquefaction depression

waves observed at the time of the Tohoku district

effect of residential land grounds with the grid-form

Pacific offing earthquake around Tokyo Bay areasoil-cement walls

within a range of horizontal distance around 50cm in“The grid-form soil cement wall” is regarded as one

the drain for an input of almost equivalent repetitionof the strong choices of the combined public facilities

shear waves on loose sand deposits, and it did not

and residential areas anti soil liquefaction measures inreach to 1m.

the detached-house areas of the regular blocks. The

From this fact, it is thought that it is necessary to

NILIM proposed to obtain the bases using computer

position the drain pipes at a distance of nearly 1manalysis of a number of model patterns in order towhen we use them as anti soil liquefaction

make check sheets to be used to judge the suitability

7)of this construction method for the individual suffering

measures.

disaster areas having various site areas and qualities(3)

Simplecalculation

sheetsforeffects

andof soil state, in 2012.

influences by the groundwater level lowering method
The City Bureau and the NILIM published “Simple(5) The centrifugal loading vibration experiments on

calculation sheets for effects and influences by thethe suitability of “the grid-form soil-cement wall”

groundwater level lowering method (trial edition).” inmethod for anti soil liquefaction measures in theAugust 2012.

detached-house areas

As for the anti soil liquefaction measures for public

The NILIM also proposed, in the 2012 budget, tofacilities and residential areas as a whole, given themeasure phenomena that occur in the ground of a

thickness of the layer of the shallow part wherelattice where houses exist with experiments using agroundwater outruns and that liquefaction does notcentrifugal force loading device in connection withoccur, the groundwater level lowering method is one

problems in liquefaction control including the effectsof the strong choices. However, we might invite

and influences of the interval distance of a latticesubsidence as a side effect due to compaction when

when the “grid-form soil-cement wall” method isthere is a layer of the viscous soil in the lower part ofapplied to anti soil liquefaction measures in thethe ground, and hence it is thought to be an obstacle

detached-house areas, to acquires necessary data,in the examination by local governments of theand to confirm the effects of measures to be taken

damaged areas as we cannot easily evaluate such

additionally.

effect and influence. Therefore, the simple calculation
sheets mentioned above were adopted as a(6) Caluculation of settlement by liquefaction using

technological assistance tool to easily grasp theairborne LiDAR measurements data

quantity of the compaction subsidence of the lower

The NILIM proceeded with the maintenance of theclay layer that is the effect of anti soil liquefaction

damage situation data of the liquefaction suffering

measures corresponding to the present conditions ofresidential areas that was necessary for the analysis

the groundwater level lowering and the side effect ofof effects and influences of the anti soil liquefaction270

measures, and proposed to maintain them in order toliquefaction measures with the columnar drain

acquire data about the change of the heights of the(Laboratory finding summary)ground and buildings in the residential areas suffering

http://www.nilim.go.jp/lab/jbg/takuti/20120509gaiy

from liquefaction by taking advantage of the recent

o.pdf

improvement of measurement precision, and toarrange them by comparison of recent data ofairborne LiDAR measurement before the suffering, in2012.
References
1) MLIT HP: “Report of the examination andinvestigation on the tsunami stricken built up area
revival techniques from the Great East Japan
Earthquake,”
http://www.mlit.go.jp/toshi/toshi-hukkouarkaibu.html
2) NILIM,

Incorporated

Administrative

AgencyBuilding Res. Inst.: “Research report of Tohoku
district Pacific offing earthquake in 2011 (2012)”
3) MLIT HP: Examination and investigation for therevival of the built up areas suffering fromliquefaction by the Great East Japan Earthquake
disaster,”
http://www.mlit.go.jp/toshi/city/sigaiti/toshi_urbanm
ainte_tk_000004.html
4) NILIM HP: “Presentation of ’simple calculation
sheets for the effects and influences of the groundwater lowering’ for anti soil liquefaction measuresin areas stricken by the earthquake (Trialversion)”http://www.nilim.go.jp/lab/bcg/sokuhou/file/120801.pdf5) MLIT HP: The decision of the adopted themes ofthe 2011 supplementary budget for construction
technology research development furtherance
system“Advertisement

for

the

technology

development for earthquake disasters,”
http://www.mlit.go.jp/report/press/kanbo08_hh_00
0169.html
6) MLIT HP: The decision of the adopted themes ofthe 2012 budget for construction technology
research development furtherance system,
http://www.mlit.go.jp/report/press/kanbo08_hh_00
0189.html
7) NILIM HP: Measurement of effects of the anti soil

271

3.3.12 Parks and Green Spaces

23 to 24, 2011, for the parks and green spaces in(1) Damage Investigation

Miyagi Prefecture in order to ascertain growth

The Great Eastern Japan Earthquake brought

inhibition of trees by salt.

devastating damages to the parks and green spaces

Regarding the damages by tsunami, we verified

along the coastal areas from the Tohoku to Kanto

inundation damages to the facilities including buildings

region due to the tsunami and ground liquefaction.

and playground equipment, pavement and signage in

The National Institute for Land and Infrastructureparks and green spaces (See Photo-3.3.12.1).

Management (NILIM) conducted field surveys at theIn addition, while damages of washout by lodging orparks and green spaces on the coast of Miyagi andbreakage were observed for trees and tide prevention

Iwate Prefecture on April 15 to 16, 2011, in

forests planted inside the parks (See Photo-3.3.12.2),

collaboration with the Parks, Green Spaces andsalt damage by seawater, plant death and reduction ofLandscape Division of the City Bureau in the Ministry

tree vitality by oil adhesion were verified in someof Land, Infrastructure, Transport and Tourism (MLIT)

species among the remaining trees (See Photo-in order to grasp the actual damages by the tsunami.

3.3.12.3).

Thereafter, a follow-up survey was conducted on June(a) Damage of Facility(b) Damage of Playground Equipment

Photo 3.3.12.1 Damages of Park Facilities (Iwanuma City)(a) Individual Tree (Iwanuma City)(b) Tide Prevention Forest (Higashi-Matsushima City)

Photo 3.3.12.2 Damage and Lodging of Trees

272

(a) Plant Death by Salt(b) Reduction of Tree Vitality by Oil Adhesion

Photo 3.3.12.3 Growth Inhibition of Trees (Tagajo City)
Also, NILIM made a field survey in Chiba and
Ibaraki Prefecture on April 6, 2011, in order to grasp
the actual damages by liquefaction in parks and green
spaces.
Damages were verified for buried objects like awater tank inside a park rising to the surface byground liquefaction due to the Earthquake (SeePhoto-3.3.12.4). We also verified buried structures likepublic lavatories and benches and the bottoms oftrees by sand boiling (See Photo-3.3.12.5), andcracks and unevenness in a square (See Photo-

Photo 3.3.12.5 Embedding of a public lavatory by

3.3.12.6). The aftermath in tree growth by sand boilingsand boiling (Urayasu City)

was not verified.
(2) Effect of Disaster Mitigation of Parks and GreenSpaces Verified by Damage Survey
The following items were verified as the effect ofdamage mitigation due to the tsunami in parks andgreen spaces in a damage survey.
1) Trees and Forests
Trees and Forests inhibited a move of castaways
due to the tsunami, and then mitigated or protected
the secondary damage that occurred due to the move
(See Photo-3.3.12.7).
Also, these trees and forests diminished the wave
Photo 3.3.12.4 Surfacing of a water tank by groundpower of the tsunami or surge, lowered the flowliquefaction (Urayasu City)

velocity and energy, and decreased the destructive
force. Photo-3.3.12.8 indicates the damage situations
in a place without a coastal forest and a place withone (broad or narrow forest width). The picture clearlyshows the worst damage without a coastal forest,
followed by with a narrow forest and with a broad
forest.

273

(a) Crack generated on the ground of a square(b) Ground unevenness on the park road

Photo 3.3.12.6 Ground Unevenness (Urayasu City)

Photo 3.3.12.7 Inhibition of a Castaway by Trees

Photo 3.3.12.9 Protective Effect on Fire Spread by(Tagajo City)

Forest (Ishinomaki City)
Also, the preventive effect on fire spread wasverified in fires that occurred due to the Earthquake as
the stoppage of spreading fire was determined at aforest (See Photo-3.3.12.9).
2) High Embankment
The effect of high embankment (observation deck)in the park was verified as a tentative evacuation areafrom the tsunami. At Minami-Gamo coast park in
Sendai City, five people including staff and visitors

Photo 3.3.12.8 Damping Effect on Wave Power by

and two pets who got left behind inside the park

Tide Prevention Forest (Ishinomaki City)

duringthetsunamiattackevacuatedtotheobservation deck on the top of a high embankment(15.89 meter elevation), and then they were rescued
by a helicopter within the day (See Photo-3.3.12.10).

274

survived and lodged pine trees after the tsunami
attack (See Figure-3.3.12.1).
The survey was conducted after the area wasdivided into three levels of Block A to C by thedamage scale of the tsunami. This site is the coastal
forest where the tsunami damage at 17 to 19 meters1)

was reported and there was no difference of tsunami
height in the survey area. The survey areas and thenumber of trees that were not washed out by the
Photo 3.3.12.10 Evacuation Site on Hightsunami in each block are shown in Table-3.3.12.1.

Embankment (Sendai City)
Table 3.3.12.1 Area and Number of Trees Surveyed(3) Survey on Damage Factors of Coastal Forest

Area

Regarding the forest area (coastal forest) withdisaster mitigation effect against tsunamis, the target
for tree growth on recovery was organized after
making clear the damage factors by investigating tree

Number of
Trees

DamageA

64.2m x 58.3m (3,743m2)

129 (113)

Small

B

2

66.3m x 52.4m (3,474m )

112 (106)

MediumC2

59 (38)Large

60.0m x 60.0m (3,600m )Note: Figures in parentheses in Number of Trees

configurations and the planting base in the damaged

show only pines.

area.
The coastal trees in "Hamabe No Mori (beach area)

1) Content of Surveyof Sendai Natural Recreation Forest" in the Ido area,
Wakabayashi Ward, Sendai City, Miyagi Prefecture

The trees were classified as "Remaining Type"

were selected for the survey area because the sitewhere a tree was standing or leaning, "Breakage

was a forest area with remaining trees even with

Type" where the root system of a tree was intact but

damages by the tsunami and had a mixture of

the trunk was broken, and "Lodging Type" where a

Aerial photograph:
Before the Earthquake

Survey Site

Location Map

Aerial photograph:
After the Earthquake

Ａ

Ａ
Ｃ
Ｂ

Block BＢ

Block C

Survey Block

Block AＣ

Figure 3.3.12.1 Survey Areas (Source Map: Google Map, Aerial photograph: Google Earth)275

tree was lodged with the root system raised or withshaped trunk, and with a small portion of canopy

the root system scoured and fallen out.

consisting of live branches and leaves (See Figure-・Tree configuration (tree height, trunk girth at chest

3.3.12.2).

height, crown height)

Then, as for the target for tree growth with a・Root system (longitudinal width, vertical depth)

configuration which will tolerate a tsunami like this・Ground level and groundwater leveltime, it was considered preferable to have 20m in treeheight, 120cm in trunk girth at chest height, 70 or less

2) Damage Factors and Growing Target

in the configuration ratio (tree height/trunk diameter ata) Tree Configuration

chest height), and 30% or more in the rate of crown

The result suggested easiness of breakage andlength (length of crown with branches and leaves/tree

lodging in a small pine with low tree height or long-height x 100).
100%

0

90%

20.7

120.0

13
1

3

Breakage
Type

1Remaining
Type

10 5

2 0

70%

115.4

0

2

100%

0

0

90%

6

8
15

80%
70%

2

6

8
3

0

0

2
6

60%

LodgingType
Breakage
Type
Remaining
Type

0

60%
50%

60.0
Remaining Type Breakage Type

Lodging Type0

Configuration ratio(b) Trunk Girth at Chest Height (c) Configuration Ratio
Figure 3.3.12.2 Tree Configuration by Damage Type

276

1
0%

0 0

1

10%
0

0

Rate of crown length70～80%

1 1

More than 80%

3

5

2

60～70%

822

28

50～60%

0%

16

30%

10%

70.0

(a) Tree Height

2

3

80.0

Breakage Type Root-returning
Type

32

20%

20%

5.0

Remaining
Type

35

1
33

40～50%

30%

87.1

90.0

4 19

1

40%

30～40%

40%

100.0

81.1

0.0

2 1
3

20～30%

10.0

1

10～20%

13.7

50%

～10
10～20
20～30
30～40
40～50
50～60
60～70
70～80
80～90
90～100100～110110～120

15.0

Trunk girth (cm)

110.0
14.6

Less than 10%

20.0

Tree height (m)

2

80%

130.0

25.0

6

LodgingType7(d) Rate of Crown Length

b) Root Systemessential to put the weighted centre of the tree form in

The configuration of lodged extension of the root

a position as low as possible in order to increase thesystem was classified in four types shown in Figure-resistance to lodging. And for that reason, deeper

3.3.12.3. "Multi-exserted Hanging Root & Two-stage

extension of hanging roots is required.

Horizontal Root Type" had the greatest root amounts
and the weighted center of the root system in a lower

40
Remaining Typeposition, and had the greatest resistance against

Lodging Type35

lodging. The ordinal configuration of the pine "Hanging
Root & Horizontal Root Type" had the second

30

Root clump volume (m3)greatest resistance and both the "Horizontal Root
Type" and "Multi-exserted Hanging Root Type" withless developed hanging or horizontal roots showed atendency to be easily lodged compared to the former

A fallen tree which theresistance to lodging was being
added by entwining the rootsystem with a nearby tree

25

20

A fallen tree with which theroot clump volume wascalculated larger due toenlargement of some root

15

types of root system.
In order to grasp the relationship between theThreshold of root clump volume for lodging to occur
y=10x
y: Root clump volume (m3)x: Trunk girth at chest height (m)10dimensions of the root system and the surface part5

supported by the root system, we estimated the ratioof dimensions of the root system to trunk girth at chest

0
0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Trunk girth at chest height (m)height (calculated as the root clump volume due to amorphologic difference of root systems) by damaged

Figure 3.3.12.4 Relationship between Root Clumpconfiguration. The results revealed an occurrence ofVolume and Trunk Girth at Chest Height bylodging when the figure deriving from the trunk girth at

Damaged Configuration

chest height (m) multiplied by 10, which is defined as3

the threshold of root clump volume (m ) for lodging toc) Ground Level and Groundwater Level

occur, was more than the values calculated by

In the relationship between damage configuration

damaged configuration (See Figure-3.3.12.4).

and elevation, the Remaining Type increased as theThen, for the growth target of the root system, whenelevation was gradually raised until 1.6m of elevation

assuming a pine tree with 120cm of trunk girth atand there was no difference between the Lodging andchest height indicated in section (a), it was considered

Remaining Types over 1.6m though the Lodging anddesirable to promote the extension of the root system

Breakage Types were major and the Remaining Type3

minor at 0.4m of elevation.

Multiple Hanging Root & Two-stage Horizontal Root Type

Hanging Root & Horizontal Root Type

Horizontal Root TypeMultiple Hanging RootsMultiple hanging roots and horizontal roots with middle
diameter develop, and in addition, the root systemhorizontally enlarges at the lower part of the hanging root.

One or two thick hanging roots and horizontal roots
develop.

There are no hanging roots, but only horizontal roots
develop.

Multiple hanging roots with middle diameter
develop, but horizontal roots don’t develop well.

Remaining Type

Lodging Type

Root System Typeto secure about 12 m of root clump volume. It is

Nothing

Figure 3.3.12.3 Configuration of Root System Extension277

In the relationship between the root system
Crown length
6m or more

extension and groundwater level, hanging roots
extended deeply in accordance with the groundwaterlevel, while vertical roots broadly extended as thegroundwater level became shallower.
As a result, we considered that it would be

Rate of crown length
30% or more

important that 1.5m or more of ground level for theTree height
20m or moredevelopment of the planting basement should be
Root clump volume: 12m3 or moreensured at minimum, and a level as high as 2.0m
of horizontal roots having developed due to an Root clump is a bowl-shaped part

extension

 Horizontal root is a root enlarging

inhibitionofvertical

roots

by

where the root system appresses soils

theTrunk girth
1.2m or morehorizontally along the ground Hanging root is a root enlarging

groundwater.

vertically to the ground(d) Conclusion
Summarizing

Configuration
ratio 70 or less(e.g.) 4.0m or more of horizontal root
Hanging root: 1.5m or more

would be required taking account of the second stage

thisevidence,thetargetPlanting basethickness 2.0m
or moretree

configuration was set at 20m or more of tree height,

Figure 3.3.12.5 Growth Target for a Robust Pine

120cm or more of trunk girth at chest height, 70 oragainst Lodging Damages by Tsunami

less of the shape ratio and 30% or more of the ratio ofcrown length for growing the pines to be a robust(4) Measures for Rehabilitation

coastal forest against lodging damages in the case of

The MLIT organized "the Research Committee forassuming a tsunami inundation height of about 20m.

Improvement of Parks and Green Spaces on the

In addition, the growth target for root system

Rehabilitation

extension under the ground on the tree configurations

from

the

Great

Eastern

Japan

Earthquake", which was composed with the experts3

was set for the root system extension to be at 12m ofon landscape, urban planning, tsunami disaster, civil

the root clump volume (ex. 4m or more of horizontal

engineeringroot, 1.5m or more of vertical root).

engineering shown in Table-3.3.12.2, in order toandenvironmental

geotechnicalIn order to ensure the root system extension, it wasinvestigate the post-earthquake town reconstruction

considered preferable to ensure 2.0m or more of soil

plan for a devastated town by the local public entity

layer thickness undisturbed by the groundwater as theand to summarize technical papers regarding theplanting basement (See Figure-3.3.12.5).

plans and designs of parks and green spaces in thereconstruction works. The Committee was held fourtimes in August 2011 through February 2012.
The Committee compiled the final report of "theTechnical Guideline on Improvement of Parks andGreen Spaces Regarding the Rehabilitation from theGreat Eastern Japan Earthquake" that would be areference for the research and realization of the postearthquake town reconstruction and project plans indevastated

towns

(See

Table-3.3.12.3).

Asareference for technical guideline, the Committee also
complied the "Technical Papers" and "Related
Documents" including the results of field surveys andengineered verifications based on the Guideline, andthe "Related Documents" and the "Application
Protocol (draft)" for the effective utilization of disaster278

wastes (See Table-3.3.12.4).
References
1) The Joint Survey Group for the Great EasternJapan

Earthquake"Information

on

the

and
Great

Tsunami(2012)

Eastern

Japan

Earthquake and Tsunami."“http://www.coastal.jp/ttjt”
Useful reference websites
1) Press Release of the MLIT "the Technical
Guideline on Improvement of Parks and GreenSpaces Regarding the Rehabilitation from theGreat Eastern Japan Earthquake," released on
March 27, 2012.
http://www.mlit.go.jp/report/press/toshi10_hh_000
097.html

279

Table 3.3.12.2 Member Composition of the Research Committee for Improvement of Parks and Green Spaceson the Rehabilitation from the Great Eastern Japan Earthquake
ChairmanCommittee

Hajime KOSHIMIZU
Mikiko ISHIKAWA
Takeshi KATSUMI
Shunichi
KOSHIMURA
Hidetoshi KOBASHI
Tomoki SAKAMOTO

Susumu NAKAMURA
Chikayasu HAMANO
Toyohiko MIYAGIMakoto YOKOHARI
ObserverKenji WATANABE
Masayuki SAKURAI
Eiji HAGA
Ryo SASAKI

Administrative
Committee

Toshiaki FUNABIKI
Yoshiaki NAGINO
Keiji NITTA
Masahiko MATSUE

Professor, Department of Agriculture, School of Agriculture, Meiji University
Professor, Department of Urban Engineering, Faculty of Engineering, theUniversity of Tokyo
Professor, Environmental Infrastructure Engineering Lab., Graduate School of
Global Environmental Studies, Kyoto University
Associate Professor, Disaster Control Research Center, Graduate School ofEngineering, Tohoku University
Deputy Director, Geology and Geotechnical Engineering Research Group, thePublic Works Research Institute (PWRI)
Chief of Laboratory, Meteorological Risk and Buffer Forest Laboratory,
Department of Meteorological Environment, the Forestry and Forest Products
Research Institute (FFPRI)
Professor, Department of Civil Engineering, College of Engineering, Nihon
University
Professor, Department of Landscape Architecture Science, Faculty of Regional
Environment Science, Tokyo University of Agriculture
Professor, Department of Regional Management, Faculty of Liberal Arts,
Tohoku Gakuin University
Professor, Natural Environmental Studies, Graduate School of Frontier
Sciences, the University of Tokyo
General Manager, City Planning Section, Prefecture's Civil Engineering
Division, Iwate Prefecture
General Manager, City Planning Section, Civil Engineering Division, Miyagi
Prefecture
Director, City Development Promotion Division, Urban Development Office,Public Works Department, Fukushima Prefecture
General Manager, Park Section, Hyakunen No Mori Promotion Division,
Construction Bureau, Sendai City
Director of Parks, Green Spaces and Landscape Division, City Bureau, MLIT
Director of Green Spaces Environment Office, Parks, Green Spaces andLandscape Division, City Bureau, MLIT
Director for Parks and Green Project Coordination, Parks, Green Spaces andLandscape Division, City Bureau, MLIT
Head of Landscape and Ecology Division, the National Institute for Land andInfrastructure Management (NILIM), MLIT280

Table 3.3.12.3 Composition of Table of Contents for “the Technical Guideline on Improvement of Parks andGreen Spaces Regarding the Rehabilitation from the Great Eastern Japan Earthquake”
Chapter 1

Summary of Study

Chapter 2

Outline of the Damages by Tsunami in the Great Eastern Japan Earthquake

Chapter 3

Basic Concepts on Improvement of Parks and Green Spaces
I.

Vision of the Post-earthquake Town Reconstruction

II. Function of Parks and Green Spaces Based on Lessons from the Great EasternJapan Earthquake
III. Basic Concepts of the Parks and Green Space Plan on the Post-earthquake Town
Reconstruction
IV. Vision of the Plan and Design for Parks and Green Spaces
Chapter 4

Basic Concepts on Application of Disaster Wastes in Improvement of Parks and GreenSpacesI.

Actions on Treatment and Utilization of the Disaster Wastes

II. Outline of Disaster Wastes in the Great Eastern Japan Earthquake
III. Process Schedule for the Disaster Wastes
IV. Applications of Disaster Wastes in the Improvement of Parks and Green Spaces
V. Planting Basement

Table 3.3.12.4 Reference Documents for “the Technical Guideline on Improvement of Parks and Green Spaces
Regarding the Rehabilitation from the Great Eastern Japan Earthquake”
Reference 1: Documents on Improvement of Parks and Green Spaces for Robust Town Development
against Tsunami Disasters
Reference 2: Documents on Applications of Disaster Wastes in Improvement of Parks and Green Spaces
Reference 3: Application Procedure of Concrete Debris into Embankment in Improvement of Parks andGreen Spaces (Draft)
Reference 4: Application Procedure of the Dump by Tsunami into Embankment in Improvement of Parks
and Green Spaces (Draft)
Reference 5: Improvement Procedure of Planting Basement (Draft)281

3.3.13 Disaster Management<Focus on both the group and its member companies>(1) Overview

Japan Federation of Construction Contractors, Tohoku Branch;

NILIM conducts deliberations concerning measures

Japan Road Contractors Association, Tohoku Branch;that should be promoted in order to ensure theJapan Dredging and Reclamation Engineering Association, Tohoku Branch;

optimum division of roles between contractors andJapan Bridge Association, Tohoku Regional Office;outsourcers. Above all, in the event of a disaster,

Japan Prestressed Concrete Contractors Association, Tohoku Branch;

surveys to ascertain the situation and emergency

Japan Civil Engineering Consultants Association, Tohoku Branch;

repairs will be carried out under conditions in which

Japan Construction Mechanization Association, Tohoku Branch;

the available personnel, organizations, technology,

National Construction Machinery and Equipment Leasing Associationmaterials, and information are severely limited.

<Focus on the group alone>

Accordingly, the management required differs fromthat needed under normal circumstances, for example,
prioritizing the input of personnel, materials, andequipment,

as

well

as

collaboration

Tohoku Federation of Construction Industry Associations, Aomori Construction
Association, Akita General Construction Association, Iwate General Construction
Association, Miyagi General Construction Association, Associated General

among

Contractors of Yamagata, Fukushima General Construction Association, Aomori

administrative bodies, and between government andSurvey and Planning Association, Akita Prefectural Land Development

private sector companies. Furthermore, the recent

Consultants Association, Iwate Survey and Planning Association, Miyagi Survey

Great East Japan Earthquake has given rise to

and Planning Association, Yamagata Survey and Planning Association,

serious problems in terms of considering construction

Fukushima Survey and Planning Association, Tohoku Geotechnical Consultants

management in the event of disaster, such as the fact

Association, Tohoku Federation of Ports and Airports Construction Associations,that it is a disaster that has affected an extensive area

Aomori Port and Airport Construction Association, Akita Port and Airport

and includes tsunami-related damage; the fact that it

Construction Association, Iwate Port and Airport Construction Association,

has occurred amid a situation in which there are

Yamagata Port and Airport Construction Association, Miyagi Port Construction

various anxieties, such as an ongoing decline in the

Association, Fukushima Port and Airport Construction Association, Japan Marine

supply of construction materials due to a sharp drop in

Surveys Association, Japan Marine Construction Engineering Association, Niigata

the number of public works projects; and the fact that

Branch of the Japan Association of Construction Divers

even bigger megaquakes are forecast, such as a

Preparedness, Response and Recovery"; and at a

Tonankai and Nankai earthquake.
Accordingly, NILIM conducted a survey from thesymposium held by the Special Committee on

twin perspective of the disaster-afflicted region andNovember 6 the same year, entitled "Strengthening

the nation as a whole that supports it. NILIM

Abilities in Disaster Response Management: Learning

developed questionnaires to consider the reality of the

From the Great East Japan Earthquake". The final

situationinresults are currently being compiled, so this chapter

collaboration with bodies including the Tohoku

will provide an outline of the outcomes identified to

Regional Development Bureau and the Special

date.

and

the

aforementioned

problems

Committee on the Great East Japan Earthquake of
the Japan Society of Civil Engineers to; these were

(2) Questionnaire Survey for Industry Groups

then distributed to construction industry groups (and(i) Questionnaire MethodIntheir member companies) and local construction

January

2012,

questionnaire

forms

were

companies in the latter half of FY2011. Reports on the

distributed to the 32 construction industry groups (andquestionnaire method and some results were reported

also to their member companies, in some cases)

at an interim briefing session of the Special

shown in the box above enclosed in a dotted line

Committee on December 14, 2011; at a symposium(group names are shown as they were at the time theheld by the Japan Society of Civil Engineers on Marchquestionnaire

5, 2012, entitled "One Year after the Quake andresponses to questions about their preparations under

Future – Large-Scale Natural Disaster Mitigation,

normal circumstances and how they responded after

282

was

carriedout),seekingtheirthe earthquake, and asking them to appraise theirwith direct support activities being carried out on theown performance in these areas. With regard tobasis of 145 of these agreements.

preparations

undernormalcircumstances,

respondents were asked about the conclusion ofdisaster agreements, the compilation of a BCP or
disaster response manual, and the implementation ofdisaster prevention drills, while in relation to their postearthquake

response,

they

were

asked

about

responses within the organization, as well as
assistance provided to others.
(ii) Overview of Questionnaire Results
90%

of

the

industry groups

to

which

the

questionnaire was distributed had established a task
force or other system within 14 days of the earthquake(March 11, 2011). Approximately 85% of industry
groups (27 groups) had already concluded a total of
93 disaster agreements with administrative bodies
prior to the disaster, with support activities being
carried out in response to requests based on 58 of
thoseagreements.

Only

nine

industrygroups(approximately 30%) had formulated or owned
disaster response manuals in addition to suchagreements, but 82 of 137 member companies(approximately 60%) had formulated manuals, which
covered a comprehensive range of topics, including
chains of command when implementing a responseand division of roles in relation to disaster responsetasks.
As shown in Figure 3.3.13.1, the support mainly
involved checks of infrastructure (assistance provided
by specialty contractor groups and constructionrelated industry groups accounted for the majority),
with other common forms of support including theprovisionandtransportof

construction-relatedmaterials and equipment, and the provision ofmaterials, equipment, and construction labor for
temporary offices, temporary housing, and evacuation
shelters. Moreover, other assistance not stipulated in
the agreements includes the supply and transport ofemergency supplies unrelated to construction, suchas drugs, food, clothing, and fuel. Among member
companies, it was ascertained that 65% had
concluded agreements directly with administrative
bodies or industry groups (a total of 285 agreements),

283

Rubble treatment for cooperation such as lifesaving and missing search [1 case]
Check of infrastructures [22 cases]
Emergency repairs of infrastructures [4 cases]
Rubble clearance, removal and transport (except lifesaving and missing search) [2 cases]
Supply of materials and equipment relating to construction work (including fuel) [10 cases]
Transport of materials and equipment relating to construction work (including fuel) [7 cases]

Major construction industry
Local construction industry
Port and Harbor work industry
Specialty work industry
Industry relating to construction
Lease/rental companies
OthersSupply of building materials, facilities and works such as temporary housing and safety [7 cases]
Dispatch of experts [1 case]
Supply of emergency supplies unrelated to construction, such as drugs, food, clothing, and fuel [6 cases]
Transport of emergency supplies unrelated to construction, such as drugs, food, clothing, and fuel [3 cases]
Others [7 cases]

0 cases

5 cases

10 cases

15 cases

Number of support activities

20 cases

25 cases

Figure 3.3.13.1 Details of Support Activities by Industry Groups and Member CompaniesNo
answers
3 cases(4.3%)"At least 50%" are also included, this figure increases

Less than20%
5 cases(7.1%)

20% andmore andless than50%
4 cases
50% or (5.7%)
more andless than80%
12 cases(17.1%)

80% ormore
46 cases(65.7%)

to approximately 80%; there was a good rating overall
in the case of member companies as well, withapproximately 85% responding "At least 80%".
However, more concerning issues were mentioned in
the spaces on the questionnaire for free-text
responses and in interviews, as described below.
1) In the construction industry, in recent years,
contractors have moved away from owning theirown construction machinery, switching to the use ofrented or leased equipment. However, no priordisaster agreement had been concluded between(a) Appraisal by industry groups

business groups in the rental/leasing sector and theNoanswers
51 cases(7.3%)

three disaster-stricken prefectures, so it took some

Less than20%
13 cases(1.9%)

20% andmore and 50% orless than more and
50% less than
13 cases 80%(1.9%) 25 cases(3.6%)

time to establish lines of communication. Moreover,the majority of construction machinery from outside
the disaster-afflicted area is leased for a fee, andthere was an absolute shortage of construction
machinery that could be sent to the disasterstricken areas. Even if machinery could be procured,cases arose in which requests for support had to be

80% ormore
597 cases(85.4%)

refused because of the straitened circumstances,including being unable to obtain fuel for construction
machinery, the trucks and drums required totransport fuel, motors, machinery operators and(b) Appraisal by member companies
Figure3.3.13.2

AppraisalofSupportmaintenance personnel, and freight vehicle drivers.

Activity

Even where business groups in the rental/leasing

Achievement Level

sector or their member companies had compiled

As shown in Figure 3.3.13.2, when asked todisaster response manuals, only in around half of all

evaluate their own level of achievement in providing

cases did those manuals contain details of the

support, approximately 65% of industry groups

status of ownership of construction machinery,

responded "At least 80%", while if those responding

materials,

284

and

equipment,

andmethodsofprocuring fuel, materials, and equipment whenundernormalcircumstances,

concerningtheresponding to a disaster.

procurement of construction machinery in the event

2) The records of disaster-stricken facilities differedof disaster, and confirming the communicationfrom the actual up-to-date status of facilities, so

framework to be used in this event. Moreover,there were cases in which it took about two months

concluding disaster response agreements between

to

the

compiletheassessments

data

requireddisasterindustry,thelease/rental

companies that own construction machinery, andMoreover,the construction machinery manufacturers that haveassessment work has been made more efficient

the technology to provide maintenance support, andthrough the use of photographs for desk-based

giving consideration to implementing management

assessments, but there were those who expressedin collaboration with the fuel and freight sectors,

the opinion that the lack of uniformity in terms of theeven when transporting equipment to the affected

way the photographs are compiled according to the

area.

and

drawings

construction

andreconstructions,(measurements,forphotographs).

structure concerned increased the burden of work

2) In terms of infrastructure management underrequired.

normalcircumstances,havingoutsourcers3) Some respondents stated that there was no control

implement improvements, such as introducing GIS

over matters that outsourcers should coordinate

in the maintenance records of each facility and(N = 411) (Multiple answers)

Factors having enabled to active speedy
0

5

10

15

20

25

30

35

40

45

To own in-house construction machineries

50 (Cases)

45

Employees know well about local areas

45

Both a construction company and cooperative companies are local ones

43

To employ in-house workers and operators

42

To have already established a system for emergency

29

With good support from cooperative companies

28

Cooperation awareness of employees

8

To enable to use the long-term experience of improvement works

8

To unite the construction industry against the disaster6

To utilize experiences of earthquakes and tsunamis in the past

4

Others5

Figure 3.3.13.3 Reasons Why Local Construction Companies Were Able to Carry Out Prompt Disaster Relief Activities
among themselves and standardize; in particular,

encouraging

some stated that there was confusion in theinfrastructure maps, as well as streamlining

management

disaster assessments; in addition, implementingof

instructions,orders,andcoordination in the disaster assessments.

thedevelopmentofelectronic

improvements relating to issues in the daily
management of infrastructure.

(iii) Tasks for the Future

3)

Giving consideration to having construction

Based on the survey of industry groups (and theirconsultants provide support to outsourcers in themember companies), it is necessary to consider the

management of the disaster assessment process.

following matters to prepare for an extensive disaster,such as the Tonankai and Nankai earthquake that is(3) Questionnaire Survey for Local Construction

expected to occur in due course.

Companies

1)

Concluding

disasteragreements

between(i) Questionnaire Method

administrative bodies and the leasing/rental sector

In September 2011, questionnaire forms were285

distributed to the approximately 1,800 companies thatrubble clearance and transport were paid for by the

are

of

customer, but the proportion of companies conducting

whichsurveys and checks free of charge was as high asencompasses the six prefectures of the Tohoku

40%. As shown in Figure 3.3.13.4, the difficulties

region, seeking their responses to questions about the

faced in conducting support activities included "lack ofsupport activities they conducted in the week after thefuel (diesel, gasoline)", followed by "breakdown ofdisaster, in partnership with the Tohoku Regional

means of communication", and "physical and mental

Development Bureau and the Tohoku Federation of

burden on employees", but companies dealt with

Construction Industry Associations, as well as their

these issues while continuing to provide support.

members

Construction

of

the

Industry

TohokuFederation

Associations,preparations under normal circumstances and how
they responded after the earthquake. During FY2011,
Shortage of fuels (gas oil/gasoline)

collated and, as of FY2012, work has started on

Shortage of construction machineries

24

Shortage of staff (workers/operators)

17

Shortage of foods

14

Difficulties faced during activities

having already been released to the press by the
Tohoku Regional Development Bureau.
(ii) Overview of Questionnaire Results
Among the local construction companies, a large
proportion had been affected by the disaster in Iwate,
Miyagi and Fukushima Prefectures (approximately
60% across the three disaster-stricken prefectures); in
particular, in Iwate and Miyagi Prefectures, more than
80% of companies located in coastal areas were

Conduct of support
activities

affected.
In the case of construction companies in Iwate,
Miyagi and Fukushima Prefectures, almost 70% of
local

construction

companies

had

Information
control Labor management

compiling and sorting the data, with some information

Lack of activity resources

the questionnaire forms that had been returned werecommenced

106

Shortage of construction materials

8

Shortage of power sources

6

Shortage of water5

Fatigue and mental burden of employees

27

Concern for radiation

8

Concern for aftershocks and tsunamis

7

Disruption of measures in communication andcontact

31

Confusion of information sources

4

Disruption of the road network

17

Parallel work with rescue activity

5

Confusion of chain of command

4

Lack of arrangement between the governments

30

support activities by 16:00, about an hour after the

50

100

150

Cases

earthquake, despite the fact that they themselves had
suffered damage. As shown in Figure 3.3.13.3, theFigure 3.3.13.4 Difficulties faced during support

most common factors cited as having contributed toactivities

their ability to commence activities so promptly
included the fact that they or a company which they

Other problems included the fact that, even whencooperated owned construction machinery, the fact

they were able to source construction machinery, theythat they employed machinery operators in their own

could not work long hours because of the shortage ofcompany, the fact that they were familiar with the local

fuel, and the fact that despite having operators, thoseterrain, and the fact that they had made advance

operators were unable to reach the sites where they

preparations based on past experience of disasters,

were needed, which was also due to the fuel shortage.

such as putting in place systems to prepare for

Moreover, with means of communication having

emergencies.

broken down due to power cuts and problems withIn terms of the support provided by local

telephone lines, it was extremely difficult to coordinate

construction companies, the most commonly-citedwith others, both within and outside the region, and toform of assistance was "emergency repairs", followed

gather information. Accordingly, many companies

by "surveys and checks", and "rubble clearance andsent messengers on foot or made use of thetransport". In most cases, the emergency repairs andcommunity wireless system to contact people.

286

hope that these will also be of assistance in(iii) Tasks for the Future

responding to an extensive major disaster such as the

The survey of

Tonankai and Nankai earthquake that is forecast to

local construction companies

suggests that consideration needs to be given to theoccur in the near future.

following matters, in order to facilitate smooth support
activities.

References

1) The development by outsourcers, local construction

1) Tohoku Regional Development Bureau press

companies, and construction industry groups ofrelease:measures focused on how to maintain construction

Promptly in the Immediate Aftermath of themachineryDisaster, July 24, 2012

andoperators,

andsystems

for

Local

Companies

Began

Activities

machinery maintenance in a situation in which

http://www.thr.mlit.go.jp/bumon/kisya/kisyah/imag

public works projects are dwindling.

es/42180_1.pdf

2) The development of regional fuel stockpiles byoutsourcers, local construction companies, andconstruction industry groups, due to the fact that
fuel shortages posed a challenge when conducting
support activities, and the fact that it was difficult tosecure a means of transporting fuel when seeking
support from outside the disaster-afflicted region.
3) As mentioned in relation to the survey of
construction industry groups, the establishment of ameans to enable outsourcers to confirm without
delay

technical

information,

such

as

designdocuments, due to the fact that the lack of suchinformation was a hindrance when conducting
checks and surveys of society capital facilities.
Moreover, the construction of a systembyoutsourcers, local construction companies, andconstructionindustry

informationtobegroupssharedthatenablesregardingfuel,accommodation facilities, and food, in order tofacilitate prompt checks and surveys.
4. Future Responses
In order to clarify the roles played by constructionindustry groups (and their member companies) andlocal construction companies, aswell asthechallenges that they faced, we would like to continue
our efforts to compile the information gathered andsummarize the outcomes in detail in publications such
as NILIM technical notes. In compiling this information,
we intend to take into consideration results fromsurveys carried out after past earthquakes, including“the Niigata-ken Chuetsu-oki Earthquake in 2007” and“the Iwate-Miyagi Nairiku Earthquake in 2008”, in the287

3.3.14 Information Field
3.3.14.1 Provision of information during Disaster or
Recovery(1) Introduction
ITS Spot-compatible

With regard to the Great East Japan Earthquake, it

ITS Spot

car navigation system

was reported that geographical concentration of
automobile or traffic jams caused by road cracks,

High-speed mass

cave-ins, and sputtered rubble as a result of thecommunication

earthquake

prevented

victimsfromsmoothlyevacuating. For the prevention of the occurrence of

Figure 3.3.14.1 Schematic Diagram of ITS Spotsuch undesirable situations, ITS-based streamlining ofServiceroad traffic or ITS-based provision of information indisasters has attracted attention as an importantmeasure. In response to this, the NILIM has beenpromoting researches on provision of information todrivers via ITS Spot, management of heavy vehicles
using probe data, and disaster-information gathering
using on-board camera. In this section, we introduce
our research activities on the above-mentioned
themes.
(2) Provision of information to drivers via ITS Spots
1) Nation-wide deployment of ITS SpotIn FY2009, ITS Spot services, as a preceding

Figure 3.3.14.2 Nation-wide Location of ITS Spots

installation, became available on the Metropolitan
Expressways. In FY2010, as the first installation in the2) Provision of information at the time of earthquake

nation-wide deployment, ITS Spots were installedoccurrence,nationwide in 1,600 locations on the expressway main

On the Metropolitan Expressway System, prior toroads, and then in FY2011, the services became

the nationwide deployment, ITS Spot services had

available nationwide (in the Tohoku district, the start ofbeen available on the following route; route 3 Shibuya,

services was delayed until August due to theroute 4 Shinjuku, route 5 Ikebukuro, city-loop andoccurrence of the Great East Japan Earthquake.)others. Those pre-installed ITS Spots, at the time of

On the inter-city expressways, ITS Spots werethe earthquake with the maximum seismic intensity of

installed at an interval of about 10 to 15 kilometers,

five on March 11 2011, provided earthquake-early-

and in addition, ITS Spots were installed on the near-

warnings as shown in Figure 3.3.14.3 .

1)side of junctions at about ninety locations. On the city
express ways, ITS Spots were installed at an intervalof four kilometers. Furthermore, at about fifty serviceareas/road stations nationwide including all theservice areas on the Tomei Expressway and the
Meishin Expressway, ITS Spots were installed.
In 2012, twenty ITS Spots were installed on
ordinary roads.

288

saving-capacity of data volume corresponding toTravel-records of about 80 kilometers.
①-2 The on-board unit transmits the saved travelrecords and the basic information (manufacturer,
model number, and vehicle specific information) to

Earthquake warningan ITS Spot when passing it, and discards therecords after the transmission.

Attention running① -3 When the volume of saved travel-records
exceeds the storage-capacity, the on-board unit

Metropolitan Expressway Information

discards the oldest data, in order by age, even if the

Figure 3.3.14.3 Warning to Drivers (actually displayed

data is un-transmitted.
①-4 The on-board unit discards and does not transmit

on the Metropolitan Expressway System)to an ITS Spot the data obtained in the range of(3)Heavy-vehicle management using probe data

about one kilometer (exact distance is up to the1) Outline

manufacturer) beyond or before a point where the

ITS Spots are radio-wave beacon-equipments

engine stops or starts.

installed on road-sides for the purpose of enabling①-5 The on-board unit informs the driver of the driving

two-way communications to cars equipped with ansafety support information provided by ITS Spots.

ITS Spot-compatible on-board unit. An ITS Spot on① -6 The on-board unit is compatible with the ETC

the road-side receives probe data transmitted from afunction.

car. Probe data cannot be used for the identification ofa car or person. However, by using additional vehicleidentification information which is added, by making
special adjustments to the on-board units, to theoriginal probe data under a contract between MLIT
and a transportation-service operator, probe data ofaudio type ITS

specific vehicles can be extracted and used. Such

Spot-compatible

probe data is called specific probe data; its application

on-board unit

GPS receiver

GPS/DSRC
one antenna

in finding travelling routes for cargo vehicles in adisaster-situation has been studied with a focus ontechnical feasibility.
The technology is expected to be effectively used tofinding travel routes for heavy vehicles. Below, we willshow the outline of the experiments conducted for

Figure 3.3.14.4 GPS-equipped audio type ITS Spot-finding travel-routes of cargo-transportation-service

compatible on-board unit

2)

vehicles .
② Summary of the experiment configuration②-1 Period of specific probe data collection: Oct. 1,

2) Outline of the Experiment
The features of the on-board unit and the outline of2011 to Jan. 31, 2012
② -2 Test vehicles: thirty-six cargo-transportation

the experiment are described as follow;① Features of GPS-equipped audio type ITS Spot-

servicecompatible on-board unit

Metropolitan Expressways.

① -1 Travel-records (time, latitude, longitude) is

vehiclesalmostregularly

using

the

②-3 On-board unit: GPS-equipped audio type ITS

updated and saved at each 200-meters run or eachSpot-compatible on-board unit.
② -4 ITS Spots: one hundred seventy-one Spotstime of 45 degrees turn. The on-board unit has a289

installed along metropolitan expressways (301.1

records of a vehicle running on expressways, where akilometers in total)

sufficient number of ITS Spots are installed, can beobtained more promptly. However, in the present

3) Analysis

situation where a sufficient number of ITS Spots have

Figure 3.3.14.5 shows a travel-records (time,

not yet been installed, such real-time capability of

longitude, latitude) included in specific probe data. In

obtaining travel-records will be lower when a vehicle

spite of losses, as previously described, of the travel-

travelsrecords in about one kilometer beyond and before the

Furthermore, data-loss will occur when a vehicle runs

engine stop/start points, it was confirmed that thein an area where GPS signal-reception is poor suchplaces believed to be the vehicles’ destinations andas in a tunnel, or when a vehicle, running along

Data-reception time: It is around 14:40 on the day.
(at the time of the first ITS Spot passage after
starting )* Go into metropolitan quantity in an early stage
after starting , pass an ITS Spot, and receive data.

on

ordinary

roads

for

longerhours.

It arrives around 13:59.
It starts around 14:25.
Place到着地・出発地はof arrival and an origin are the
最大半径以内
maximum
radii 1kmof less
than 1 km.

14:25:04" "" 14:25:08""
13:58:41""
14:26:27"" " 14:25:33"
14:27:03
14:33:23""" "14:28:42 " 13:56:13
14:34:07" " 14:30:08"""
13:55:21
14:29:04""
14:34:20
13:54:59"
14:34:33""14:35:25
13:54:19""
14:35:59
13:53:47""
14:36:15
13:53:27"
14:36:26""
13:53:00
14:36:36""
13:52:23
14:36:46""
13:50:47
14:37:10""
13:50:30""
14:37:31
13:49:19""
13:47:30
14:37:41"" 14:37:50
13:45:1013:45:14"""13:43:57
14:38:00"
13:43:38"
14:38:10"
13:43:23" 14:38:19"
13:43:07""
14:38:29
13:42:37""
14:38:40
13:41:30

Introductory
【】
notes

Run Course

The 輸送先と思われる場所
place considered to betransportation
place（滞留時間による推測）(Guess by holding time)

走行経路の進行方向
The
direction of movement of arun courseaFigure 3.3.14.5 Example of Travel-route extracted Travell-records
the arrival/departure time are successfully estimatedordinary roads during a large part of its travel, lessby extracting the places where the vehicle stops forfrequently passes ITS Spots, and data-loss will also

more than 5 minutes.

occur as a result of the mechanism described in 2).
①. 3).

If the specific probe information is delivered on areal-time basis, the location information and travel-290

(4) Disaster-information gathering through on-board

emergency

camerainformation equipments such as CCTV, transmission1) Introductionof video information from the site of disaster through

Althoughresearchdevelopmentof

information-gathering

by

the

small satellite-image-transmission equipment, road-technologies on the detection of unordinary events

information gathering through emergency patrol, andthrough automatically processing and analyzing

reports

images provided by road-monitoring cameras and“Earthquake Emergency-Patrol Action Plan” requires

trials for their deployment have been done, suchthe following: road patrols should be done with focus

approaches using ITV images for automatic detection

on passability/impassability on the outward-path, andof unordinary events will not fully satisfy theroad cracks, on-road obstacles, landslides, and rock-requirements

disaster/accident-information

falls on the inward-path; the onward-patrol should begathering: for example, the detection will be effective

completed approximately within an hour of earthquake

only at the camera-installation sites.

an occurrence, and the inward-patrol should be

in

and

measures,On the other hand, an increasing number of cars

from

road

users.

Furthermore,thecompleted within two hours after the completion of theare expected to have cameras mounted mainly foronward-patrol.

recording video at the occurrence of automobile
accidents. Not only at the time of accident occurrence,

Table 3.3.14.1 Object for Information-gathering

those cameras have proven to work effectively, even if

required in the Business Continuity Plan, MILT

insufficiently, recording data even when a car is

Objectrunning along a route under a viaduct.
information obtained through on-board camera toandutilizationofAllowable Hours
to Report
1 2 3 4

1. Information required as quickly as possible(1) Facility Damage
River-FacilityRiver Bureau●
Pediment DisasterRiver Bureau●
River Bureau, and Ports●
Cost-security-Facilityand Harbors Bureau
Expressway, National Highway,
Road Bureau●
Regional Road
Railway Facility
Railway Bureau●
Port Facility, Navigation Channel Ports and Harbors Bureau ●Air Port, Aviation Security Facility Civil Aviation Bureau●(2) Status of Traffic and Transportation Service
Close / Open of Expressway
Road Bureau●
Railway
Accident,
Service
Railway Bureau●
Cancellation
Aviation
Accident,
Service
Civil Aviation Bureau●
Cancellation(3) Situation of Government Office Building and Communication Facility
Information and Communication
Minister’s Secretariat●
Facility
Lifeline
Minister’s Secretariat●
Government
Buildings
Government Office Facility●
Department
2. Information required, not urgently(1) Facility damage
Sightseeing tour facility (registered
Policy Bureau●
hotels or inns)
CityandRegional
Urban Park
Development Bureau
Building
Housing Bureau
Sewage and Wastewater
Maintenance Department,
Sewage and wastewater system
CityandRegional
Development Bureau(2) Status of Traffic and Transportation Service
Director-Generalfor●Commercial warehouse
Logistics
Automobiletransportation
business
Road Transport Bureau●(service
informationofexpressway-busses, and accident

The challenges to be solved for applying video
gatheringResponsible Organization

disaster/accident

information will be shown below.
2) Road-management organization’s activities for
information-gathering“Plan for Road Maintenance,” prepared by eachregional development bureau or national-highway
office of the MLIT requires emergency road patrols in
the incident of heavy rains or earthquakes. Table3.3.14.1 shows the list of information required to begathered in the “MLIT Business Continuity Plan.” Theplan requires collection of the following information
promptly for making the first press release in an hourof the collected information and well-organizeddisaster information: road damages; facility damages;
open/close of expressway. At the same time,“Operational Plan for Disaster Prevention” preparedby each regional development bureau and eachnational highway office, which describes measuresagainst earthquakes, wind and flood disasters,
volcanic disasters, snow disasters, road disasters,
river-water quality disasters, massive fire disasters,
and nuclear disasters, requires, as one of the

291

●
●
●

information of trucks and others)
Marine traffic(accident / service information of Maritime Bureau
passenger vessels)

3)

Enhancement

anddetect unordinary events and make a judgment on●them.
③ Data transmission process: via communication-line

improvementoftransmitting

roadmanagement
organizations,

how,

by

the

centercollected

images,④ Data utilization process: the road-management

On the basis of what is required of roadmanagementtodetection and judgment on events.
organization makes decisions and actions using

on-board

information of event-detection or judgment, such as

cameras on a car, the conventional measures can beordering emergency patrols or information delivery

improved or enhanced is shown in Table-3.3.14.

to other management-organizations or road users.
Note that the processes ② and ③ could appear

Table 3.3.14.2 Conventional measures of Information-in various phases and take various forms: they could

Gathering, and Its Enhancement or Improvement

appear as preprocessing such as mapping, in on-

enabled by using ITS Service
Conventional
Enhancement
orMeasuresof Improvement enabled byInformationusing ITS Service
Gathering
Road patrol (at the Prompter decision-making ontime of disaster)
open/closeusing
visualinformation
Event detection or visual
Unordinary-event
detection
through inspection even at a placeinformation gathering not covered by informationequipments (at the gathering equipments
time of disaster)
Report from road Increase of number of reports
information
volumeusers (at the time of ordisaster or in normal encouraged by easiness inreporting or automatic (unsituation)manned) reporting
Easy finding and visualizationof event-location and severity
using
hybrid-reportwithimages and location reportboard equipment; they could appear in the image-dataprocessing only after the transmission to a center ofthe entire image data.

①

Data

on-board unit

②Data processing③Data transmission②Data processing
The center side
④Data practical use
Figure 3.2.14.6 Schematic Diagram of Concept Model
5) Major managerial or operational action-items① Data gathering process
The action-items for this process are as follows:4) Concept model

proprietary-right of data: who owns the right;

Figure-3.3.14.6 shows a schematic diagram of theconcept-model explaining the scheme for applying

motivation of data-collection: how data-gathering

images obtained on-board cameras to road-action could be motivated; selection of cars: how tomanagement; the model consists of four processes,

determine a car in which an on-board unit is installed;① to ④, as follows:

long-term operability: how to build a system for① Data gathering process: extracting and collecting

maintaining the performance and accuracy.
② Data processing process

images, locations, acceleration, and others from theinformation obtained through on-board camera on

In a case where the process is to be accomplisheda running vehicle (service vehicle running along ain an on-board unit, the on-board unit has to be

fixed route such as a road-management service

enhanced with additional functions;vehicle or a route bus or other ordinary vehicle)･ Then, how can manufacturers be motivated to②Data processing process: processing and analyzing

develop such enhanced equipments; how to decide

the collected data— images, identified locations, to292

applicabledata-processing

detection

andjudgment

methods
—

this

for

event-

would

requirecomparison and trade-off analysis in terms of cost-assessments on road managers’ requirements.

effectiveness and necessity in road-management.

② Data processing process③ Data transmission process

For this process, data processing methods must be

As for this process, preparation or development ofdetermined to properly detect and make judgments oncommunication lines, and payment — who will bedifferent types of unordinary events. The process ofcharged — is to be decided. In addition, because

data gathering, combination, and integration ofimages to be transmitted could include personal

different images given by different on-board cameras

information, security measures should be studied inincluding those by ordinary cars, dealing with different

relation to laws and regulations such as the Private

types of image-processing methods, might result in a

Information Protection Law.

risk of fluctuation in detection accuracy or judgment④ Data utilization process

criterion. Furthermore, such a variation in processing

As for this process, comparison and trade-off

methods could make it possible for intentional false

analysis in terms of cost effectiveness, necessity indata to pass. Therefore, certain standardization ofroad management, and security measures will beprocessing methods or a performance certification

required on in what range the event-detection andsystem should be considered.

judgment information or images could be shared and③ Data transmission process
In determining the data transmission method —how to archive and make public such information.
Especiallydata

although a method unconstrained by the dataacquisition/transmission is performed in collaborationtransmission timing, location, or volume is idealistic,

withgiving great latitude in the selection of data processing

socialina

networks,

caseroles,

where
expensesandresponsibilities should be clearly identified and allotted

methods —to involved entities. In addition, because the accuracytransmission channels are limited in volume andof the information provided by in-vehicle units could be

provided on a pay-basis, the transmission method

a major issue, studies will be required on in whatshouldcontext

analysisinroadmanagement

operation

such

information could be used.

because the actual and available

beselectedandthroughassessments

cost-effectivenessonthetechnical

requirements of the data processing method, focusingonthetransmission

occurrence

frequency,

6) Major Issues in Technological or System Designtransmission speed, and transmission channel type.

① Data gathering process④ Data utilization process

One of the major problems in this process is

In this process, considerations should be given tobrought about by the differences in formats oreffectively setting the thresholds in the detection andspecifications of the data to be gathered. Because on-

judgment of abnormal events. In addition, in the caseboard cameras that have become available on thewhere information is shared among various managing

market adopt different specifications or standards forentities,

image devices, resolutions, frame-rates, or image-filetransmission/saving format will be required.

standardization

of

the

data

formats, in order to integrate and utilize the imageprobe information given by ordinary cars, technical7) Collection of basic data for the estimation of

considerations and solutions are required for thedetection accuracy

integration of those data. In addition, system design or

In order to estimate the accuracy of detection oftechnological considerations are required on the data-

unordinary events — how precisely can those events

gathering timing — data is acquired continuously, onlybe

before and after triggers generated by accelerations,experiments using their test road.

detected

—,

NILIM

conducted

preliminary

at some predetermined positions, or controlled by the

The outline of the experiments is shown as follows:

driver’s voice command — through technological

A number of stones were placed on the test road. A

assessments,

cost-effectivenessanalysis,ordrive-recorder makes shots of those stones. Those293

images are saved as the images supposed to be

Table 3.3.14.3 Result of Object-Detection

obtained through on-board camera. Image-analysis

Size of tracking data per frame

software analyzes those images to extract objects.

100
pointsNG

500
pointsOK

1,000
points
OK

NG

NG

OK

NG

NG

NG

NG

NG

NG

NG

NG

NG

Table-3.3.14.3 shows the results. “OK” signs there
Distance to Object:
10m
Distance to Object:
20m
Distance to Object:
30m
Distance to Object:
40m
Distance to Object:
50m

indicate that object feature point such as corners or
silhouette-boundaries were successfully detected.
At the test-distances longer than 20 meters,
detections were unsuccessful. However, at distancesless than 20 meters, objects were more successfully
detected as the tracking number (number of featurepoint -detection) increased. Note that numbers shownin the photo in Figure 3.3.14.7 are the numericconversion of feature point.
Tracking data numbers per frame :100units

Tracking data numbers per frame :1000units

Tracking data numbers per frame :500units

OBJECT：UNDETECTABLEOBJECT：DETECTABLEOBJECT：DETECTABLE

Figure 3.3.14.7 Result of Image Analysis (Distance to object: 10m)

(5) Conclusions

1)

In this section, we reported our activities on

ITS.” Japan Institute of Construction Engineering

information-provision to drivers through ITS Spots,
management

of

heavy

vehiclesusing

Akiyama, Satoshi. “Japan’s New Initiatives in
2011.

probe

2)

information, and disaster-information gathering using

Tanaka, Yoshihiro, et al. “A study on low-cost
logistics support service utilizing ITS Spot.” 19th

on-board units. We are required, for expanding our

ITS World Congress: AP-00177, 2012.

activities described here, and for solving the problems

3)

Suzuki, Shoichi, et al. “A study on challenges ofour research activities have revealed, to conduct

technologies

proof-of-concept experiments, accept the evaluations

information on road network using in-vehicle

by road-management organizations, propose andcameraprove the feasible services, and promote studies on

Infrastructure

the information items, their contents and their

Research Conference, 5b Disaster Information (6),operation schemes that should be standardized.

2012.
4)

collecting

images”

anomalous

Proceedings,

Planning

and

the

event
45th

Management

Ministry of Land, Infrastructure, Transport andTourism. “Business Continuity Plan, MLIT.” 2007:

References

7.

294

5)

Kurihata, Hiroyuki, et al. “Rainfall recognition forvarious conditions using an in-vehicle camera
image for driver assistance.” Technical Report of
IEICE. PRMU2005-267, 2007.

6)

Kyutoku, Haruya、et al. “A study on General
Obstacle

Detectionby

Spatio-Temporal

Subtraction with Past In-Vehicle Camera Image
Sequence.”

Technical

Reportof

IEICE.

PRMU2009-273, 2010.
7)

Kyutoku, Haruya, et al. “Detection of Forward
Obstacles from In-Vehicle Camera Images by
Temporal-Subtaction of Road-Surface.” Meeting
on

Image

Recognition

andUnderstanding(MIRU2009),”2009.
8)

Tanaka, Michio, et al. “Dry/Wet Judgment ofRoad Surface Using Gabor Filtering of Vehicle
Camera Images.” Technical Journal of IEICE.
ITS2010-63, 2011.

9)

Seki, Mikio. “Indexing of In-Vehicle Camera
Image using Color Information and Knowledge
Processing.” Denso Technical Review, Vol. 12,
No.1, 2007.”

10) Shimada, Shigeru. “System proposal of alwaysarchived drive recorder by using smart phone and"Vider" new video services.” ISP J SIG Technical
Report, Vol. 2009-ITS-38, No,2, 2009.

295

3.3.14.2 Correction of coordinates of road ground(b) Development of Fundamental Geospatial Data ofcontrol points and fundamental geospatial data of

Roads

roads

The Fundamental Geospatial Data of Roads is(1) Summary

maintained by converting into GIS data the completion

From the viewpoint of ensuring accuracy of maps, itdrawings of road work by road offices, etc. When roadis also essential to revise the coordinates of maps thatwork is done on subject roads, the development andwere changed by the large-scale crustal movement

update of the maps is also planned, and structurescaused by the Tohoku Pacific Offshore Earthquake.

are established for carrying out the development

In this paper, we report on correction of coordinates

under the minimum budget required.

following the crustal changes caused by the Tohoku
Pacific

Offshore

Earthquake,forMoreover, the maintenance of completion drawings

fundamentalof works is based on the “Manual of Completion

geospatial data of roads, which is a large-scale road

Drawing Production for Road Works” so it ismap, and the road ground control points used as

maintained with uniform accuracy.

reference for positional information of roads, managed
by the Ministry of Land, Infrastructure, Transport and2) Summary of road ground control points

Tourism.

(a) Background of road ground control points
development(2) Summary & background of fundamental geospatial

As described above, Fundamental Geospatial Data

data of roads and road ground control pointsof Roads is created based on completion drawings of1) Summary of fundamental geospatial data of roads

works, so they are made in the form of several(a) Background of development of fundamental

hundred meter long maps as separated sections, andgeospatial data of roads

when using them it is necessary to join/standardize

The information handled under road management

the maps using high precision latitude and longitude

includes administrative inquiries from road users, roadinformation.

surface records, locations with many accidents, etc.

“Kiloposts” are one of the 30 features of the

Much of this information can be shared between

Fundamental Geospatial Data of Roads used as theoperations, and having a structure for information

control points for seamlessly joined and standardized

sharing enables more efficient road management.

maps. The road ground control points are maintainedWith the objective of supporting this kind ofwith the main objective of providing accurate

efficiency of road management, the Ministry of Land,

coordinates information on these kiloposts.

Infrastructure, Transport and Tourism is developing“Fundamental Geospatial Data of Roads” which is(b) Early-stage development of road ground control

large-scale (1/500 or 1/1,000) GIS data, that gives

pointsdetailed expression of 30 types of road structure

For the road ground control points, metal rivets arefeatures, as shown in Figure 3.3.14.8.
road managementboundarybuildingarea
sidewalk

car parking area
(bicycle parking
area)

installed near the site marks created on the roadshoulder etc. as shown in Fig.3.3.14.9, for measuring
the coordinates. The development is carried out inintersectionpedestrian crossing overpass
planting
carriageway
stop line
stationroad centerline
divider marking
area
Traffic island
traffic island
Structurekilopost
abutment
pedestriancrossing
sidewalksidewalksidewalkpedestrian crossing
carriageway area
box culvert
stop line

accordance with the “Development Outline for Road

kilopost
Traffic
islanddividermarking
planting

sidewalk

GroundControl

Points(Draft)”(hereinafter“Development Outline (Draft),” while accuracy ismaintained by keeping the measurement error within
about 7~8 cm for latitude and longitude, and within
about 10~20 cm for altitude.

Figure 3.3.14.8 Image of Fundamental Geospatial Data of Roads

296

Roads that were changed by crustal movement, etc.
Site mark (Sign)* The name in theFundamental
Geospatial Data ofRoads is “Kilopost.”

Based on data released by GSI, Fundamental* KP (Kilopost)” indicates a site
mark located every 1km fromthe starting point.
For example, the site mark at
3km point from the starting
point is expressed as “3kp.”

Geospatial Data of Roads was extracted for regions inwhich correction parameters were published by GSI
after the changes in the crustal movement caused by

Measure latitude,
longitude andaltitudetheTohokuPacific

Offshore

Earthquake.

The

extraction also included Fundamental Geospatial Data

Road groundcontrol point
MLIT

of

Road ground control point (Simple marking rivet)

Roads

requiring

coordinate

correction

after

previous earthquakes (Noto Peninsula Earthquake,
Figure 3.3.14.9 Image of road ground control pointsetc.).

development(b) Sorting of coordinate correction procedures(3) Effects of crustal movement caused by the Tohoku

In order to implement the coordinate correction ofPacific Offshore Earthquake

Fundamental Geospatial Data of Roads extracted in

1) Crustal movement caused by Tohoku Pacificthe preceding paragraph, the coordinate correct

Offshore Earthquake

methods and procedures were sorted based on the

The Tohoku Pacific Offshore Earthquake caused

data published by GSI.

large-scale crustal movement, mainly in areas on the

The Fundamental Geospatial Data of Roads GIS

Pacific Coast of Eastern Japan. There was adata is created by automated conversion of thehorizontal movement of more than 20cm in the area

completion drawings of works CAD data, so in orderwhich reaches as far as Nagano prefecture andto prevent inconsistencies in the computing stage, as

Toyama prefecture, and also a large-scale verticalshown in Fig-3.3.14.10, it was decided to convert thesettling in areas on the Pacific Coast of Easterncoordinates of completion drawings of works CAD

1)Japan.

data and afterwards do automated conversion tocreate the GIS data.

2) Provision of correction parameters

Moreover, the application of coordinate correction

Subsequent to the aforementioned large-scaleparameters and altitude correction parameters incrustal movement, since October 31, 2011 thecompletion drawings of works CAD data enabled

Geospatial Information Authority of Japan (hereinafter

coordinate correction program development and batch"GSI") has been providing coordinate correction

corrections.

parameters and altitude correction parameters forcorrecting the coordinate value of public control points
Management file ofcompletion drawing
for road works(Before correction)etc., to correct the horizontal and vertical gap
1)

generated by the crustal movement.
Thecoordinate

correctionofFundamental

Geospatial Data of Roads and road ground control
points managed by the Ministry of Land, Infrastructure,

Management file ofcompletion drawing
for road works (Aftercorrection)

Transport and Tourism was decided to be carried out
based on the relevant correction parameters.

Automatic
conversion

Coordinate
correction
calculation of CAD
data for completiondrawingCalculation
conformed toPatchJGD(Coordinate)(Altitude)

Correction by the coordinate correction program

Correction
parameters for
the Tohoku
Pacific Offshore
Earthquake
Correction
parameters forearthquakes in
the past

XML-formatted
data file (Aftercorrection)(4) Coordinate correction of fundamental geospatial
data of roads and road ground control points

Figure 3.3.14.10 Basic operation procedure of1) Coordinate correction of Fundamental Geospatial

coordinate correction

Data of Roads(a) Extraction of Fundamental Geospatial Data of(c) Implementation of coordinate correction297Based on the aforementioned coordinate correction2) Coordinate correction of road ground control points

procedure, the coordinate correction of Fundamental(a) Extraction of road ground control points that were

Geospatial Data of Roads was done using thechanged by crustal movement, etc.

coordinate correction program. Fig. 3.3.14.11 is an

The road ground control points that were changed

example of correction using the coordinate correction

by the crustal movement caused by the Tohoku

program.

Pacific Offshore Earthquake were extracted based on
the data published by GSI. The extraction also
includedroadgroundcontrol

pointsrequiring

coordinate correction after the previous earthquakes(Noto Peninsula Earthquake, etc.).
(b) Implementation of coordinate correction
Coordinate correction of the road ground control
points extracted above was implemented using thecoordinate correction software Patch JGD provided by
GSI. Fig. 3.3.14.12 is an example of coordinate
Beforecorrection

correction at a site (National highway 45, site 46kp)
having large coordinate parameter values.

Aftercorrection

Figure 3.3.14.11 Correction by coordinate correction
program (example)For

post-correction

accuracy,

2,226m of altitude →1,756m→1,791m(0.435m of total settlement [0.035m of uplift in the Great East
Japan Earthquake])comparative

verification was done against the computation resultsof a coordinate correction software Patch JGD

Before correction

provided by GSI, to check whether the quality was

After correction

maintained.
The coordinate shifts about 4.4m.

(d) Creation of coordinate correction procedure
manualFigure 3.3.14.12 Coordinate correction of road ground

The Fundamental Geospatial Data of Roads is to becontrol points (example)

maintained and updated in the future, so it is predictedthat Fundamental Geospatial Data of Roads requiring(c) Sorting of correction operation procedures in view

coordinate correction would also be sequentiallyof future maintenanceregistered and accumulated in the future. Therefore,

There is a need for reinstallation/resurvey of a roadthe coordinate correction method and procedures

ground control point in case of loss of the control point

arrangedtheitself, and resurvey of sites for which correction“Fundamental Geospatial Data of Roads Coordinateparameters are not provided, so it is difficult to

Correction Procedure Manual” was created.

implement coordinate corrections in the same way

this

time

were

compiled,

and

using

298

the

correction

parameters.

Moreover,regulations for early-stage development play a central

Earthquake etc., the correction operation proceduresrole in the Development Outline (Draft) and there were

were developed, actual correction work was done,

not enough description on maintenance and update

and accuracy was obtained.

after its development.

Henceforward, in order to consolidate and manage

Because of this, in view of future maintenance andupdateofroadgroundcontrol

points,the results of inspection surveys of road groundthecontrol

pointsandensuretheaccuracyofDevelopment Outline (Draft) was revised to the “Road

Fundamental Geospatial Data of Roads and road

Ground Control Points Development/ Maintenanceground control points, the plan is to continuallyand Update Outline (Draft),” and operation methods

supportfor

Development Bureaus, etc.

handling

suddenandlarge-scale

crustalcoordinate

correctinginRegional

movements caused by large-scale earthquakes werealso investigated, and “Road Ground Control Points

References

Maintenance and Update Manual for Occurrence of1) Crustal movements in permanent GPS monument

Large-scale Crustal Movements (Draft)” was created.

obtained from GPS observation (Geospatial

Fig. 3.3.14.13 is the work flow of that manual (draft).

Information Authority of Japan web site):www.gsi.go.jp/chibankansi/chikakukansi40005.ht
mlSituation check of road ground control points
Check of damage situations such as breakage, loss and local ground deformation

2) Road ground control point guidance system web

Selection and classification of road ground control points inapplicable to correcting
parameters

Road ground control points applicableto parameters

Road ground control points requiring
reinstallation and resurvey

Correction of coordinates and altitude by parameter

Replacement and resurvey of road groundcontrol points

Coordinate correction using parameters

Replacement of road ground control points

Error check by the inspection survey

Resurvey of road ground control points

site: http://www.road-refpoint.jp/

Arrangement of the results
Registration in the Road Ground Control Point Guidance System after
compiling electronic delivery products

Figure 3.3.14.13 Work flow of road ground control
points coordinate correction as per the manual (draft)(d) Implementation of reinstallation and resurvey, etc.
Based on the aforementioned manual (draft), theRegional Development Bureaus will provide support
for inspection surveys of road ground control points
that can be corrected using parameters, andreinstallation work for road ground control points
requiring reinstallation and resurvey in the future.
The results of these operations will be registered in3)

the “Road Ground Control Point Guidance System”

in which the nationwide road ground control points
information is centrally consolidated and managed.
(5) Conclusion
With regard to the coordinate correction of the mapsthat were changed by the large-scale crustal
movements caused by the Tohoku Pacific Offshore299

3.3.15 Coastal Environment

on rehabilitation of the ecosystem because of the

In the coastal environment, technical supports onpriority setting. An investigation of bottom sediments

discharge of pollutants into the coastal area, recovery

in Matsushima Bay was conducted as an independentand conservation of the coastal ecosystem andsurvey of the National Institute for Land andenvironmental considerations in rehabilitation andInfrastructure Management (NILIM) with the support ofrecovery constructions were conducted.

the local office in May 2011. After the survey, NILIM

Detailed on-site information regarding the coastal

had started a survey on the regeneration of eelgrass

environment had not been acquired after thebeds

occurrence of the disaster in spite of efforts collecting

established an NPO cooperation work "the Project forin

MiyakoBay

since

November

2011,

issued information from the press or involved parties

Bond of Revival Connecting the Eelgrass Beds

1),2)

Restoration" in April 2011, and worked together

possible problems of the environmental situation ofthrough sharing the survey results.

. A month after the disaster, NILIM identified thethe disaster including a discharge of pollutants into thecoastalarea

anddegradation

of

the

From the end of 2011 to 2012, investigative

coastalmeetings on the environmental rehabilitation for the

ecosystem , and environmental considerations on

recovery were established in Matsushima, Ofunato

3)

4)

Seekinganand Miyako Bays, respectively. NILIM is attempting toinvestigations

andmake technical cooperation and support by including

considerations, NILIM promoted awareness on thethe chief of the Marine Environment Division and aenvironmental considerations, notified a necessary

research officer for Advanced Port Technology in the

support system to the Tohoku Regional Development

meetings. Also, in the NHK Special "the Hidden

Bureau through the Marine and Environmental

Radioactive Pollution - an Urgent Report from theDivision of the Ports and Harbors Bureau in the

Ocean-" on January 15, 2012, the program introduced

headquarters of the MLIT and decided to wait for a

the present status of the possibility and progressive

request (Figure-3.3.15.1).

process where cesium would have transported andrehabilitation

andunderstandingforrestorations .
thesedeposited in the river mouth areas by beingtransported via the air, flown into the rivers and

The Marine Environment Division of NILIM, on July 27, 2011

Regarding problems relating to the earthquake disasterreconstruction on the environment

absorbed in the grains of mud. The program also

・Urgent problem in the port and harbor environment as to confirm chemicals
and diffusion/accumulation of sludge

revealed problems such as radioactive pollution of- Anticipation against secondary hazards to health and fisheries *Oil spill in Ofunato- Examination required on the treatment method when removing sludge

earth and sand on the seabed.

・Items to be required for an urgent survey

In- Criterion for health items in water and water bottom sediment (a few points in the port)- Mapping of diffusion/accumulation information with analysis of specific environmental
items in sediments (inside the port or at the waterside, or in the bay at the points ofdecades)Onahama

and

Soma

Bays,

investigative

meetings were conducted in order to handle suchproblems.

・Items for which cooperation is possible as the Marine Environment Divisionof NILIM

The summarized situations are reported by region- Planning of the surveys mentioned above- Implementation of on-site collection of water and sediments- Analysis implementation (to be outsourced from the NILIM)- Besides the analysis described above, estimation of the sedimentation area by a simple
simulation- Development of a wide-ranged map with high resolution using the environmental
evaluation sonars- Necessary environmental surveys toward the future reconstruction (Possible to joinorganization such as the Fisheries Research Agency)- Proposal preparation on the items of environmental concern toward the reconstruction
plan* Assuming initial motion surveys in black letters (1-2 months), full-scale surveys in red
letters (6-12 months) and later surveys in blue letters (1-a few years)

as follows.
(1) Sendai and Shiogama Port and Matsushima Bay
The Gamo Tideland is located near Sendai and
Shiogama Port and was an area with a higher
consciousness about environmental conservation for5)some time . Gamo Tideland itself lost a large part of

Figure 3.3.15.1 Memorandum of Problems on thesand banks in the seaside area and experienced a

Coastal Environment (July 2011)

drastic change in the environment of lagoons andHowever,

the

local

site hadtidelands with the coastal forest.

not requested

NILIM visited Gamo Tideland in May 2011 whenmonitoring to grasp the current situation or researches

conducting the aquatic survey in Sendai and300

Shiogama Port and Matsushima Bay, and verified thebirds in the new environment and strength of thecurrent

situationobservation

of

the

ecosystem(Figure-3.3.15.2).

Despitebyvisualreproduction power in the coastal ecosystem was

a

large

observed.

topographical change, the existence of benthos and(a) Seaside(b) Landside
Figure 3.3.15.2 Gamo Tideland after the Earthquake (May 5, 2011)
In the survey at Matsushima Bay in May 2011, thesampling sites were determined after calculating the
diffuse situation of effluents from the land area
(Figure-3.3.15.3)

andpredicting

theextentofexpansion in advance. At the survey area, however,the sampling was not conducted as scheduled
because the opening work was being conducted for
floating oyster rafts or nets and the research ship
could not intrude into the water areas except theseaway. Thanks to full cooperation from the local
office, sampling was done within the area accessible
from both the sea and land sides (Figure-3.3.15.3).

301

Bottom sediment sampling was done with anenvironment in Matsushima Bay, (2) Basic study on

Ekman-Birge grab at 2cm of the surface three times or

the measures for recovery of the coastal environment,

more. These samples were mixed and provided as(3) Basic study on the whole concept of beach

the assay sample. The analysis result showed thatdevelopment, (4) Prediction of effects on recovery offive items including arsenic and its compounds,

the coastal environment and (5) Others relating to thefluorides, vanadium and its compounds, mercury andrecovery of the coastal environment in Matsushima

its compounds and polychlorinated biphenyl wereBay. The research officer for

Two dimentional single layer load-flow calculation (1.2m of difference of tidal level,

Dye throw-in point)

Advanced Port

Two dimentional single layer load-flow calculation (1.2m of difference of tidal level,

Calculation start: After 138 hours = 5 days and 18 hours = at low tide after 11 tides

Dye throw-in point)

Calculation start: 144 hours = 6 days = at high tide after 12 tides

Figure 3.3.15.3 Results of Simplified Simulation for the Diffuse Situation of Effluents from the Land Area in
Matsushima Bay
Sendai-Kamaishi Port Survey
The Japan Hydrographic Association
NewPEC:Free download version, February 2011
NP07
East coast of Honshu Island

B Transparency: 0.7m
C Transparency: 1.1m

○ Mud collection point (A-C: From the land)(1-5: From the sea)
○ Survey point(6: No mud collected)

A Transparency: 1.7m

Transparency: 1.4m 5

6 Transparency: 1.6m
3 Transparency: 1.5m
4 Transparency: 1.4m
2 Transparency: 1.9m
1 Transparency: 1.3m

Stationnumber
St.A
St.B
St.C
St.1
St.2
St.3
St.4
St.5
St.6

North latitude
Degrees
38
38
38
38
38
38
38
38
38

Minutes
20
22
22
18
19
19
19
19
19

Observation
schedule
Days
Hours

East longitude
Seconds
34.8
52.56
11.7
41.81
2.43
23.52
17.43
13.44
35.24

Degrees
141
141
141
141
141
141
141
141
141

Minutes
8
6
3
2
3
3
1
1
5

Seconds
50.02
59.22
57.36
33.62
7.36
12.99
59.3
43.02
12.79

May 5

15:00 17:00

May 6

10:00 14:00

Figure 3.3.15.4 Research Sites for Sediment Sampling in Matsushima Bay (May 2011)detected out of 34 items of health related materials,

Technology of NILIM chaired the meeting and the

but all of the values were largely lower than eachchief of Marine Environment Division joined as anstandard and no treatments were required.

observer.

In May 2012, the investigative meeting on recovery

The investigative meeting has supported someof the ocean environment in Matsushima Bay was

events like field observation and citizen participation

established and started to investigate the following

types of events (Matsushima Bay beach learning withitems: (1) Grasp the current situations of the coastal

parent and child, focusing on investigation toward302

recovery of eelgrass beds in the bay. Moreover, in the

Tidal Flats in Miyako Bay has continuously monitored

renovation of Kitahama Green Space revetment

such situations , and conducted educational activities

planned in advance, in order to conduct a properin the region. After the Earthquake, NILIM also

environmental consideration, NILIM has progressively

conducted an observation of the fry in May 2011 andconducted

the first survey in seaweed beds on June 16, 2011,

supports

forenvironment

8)

recoveryincluding the participation of the research officer forand kept records on the remaining eelgrass beds.

Advanced Port Technology as an expert in the forum

Mr.

Suchinobu

Yamane,chairmanoftheof Kitahama Green Space revetment that wasconsociation, reported the current situation of eelgrassestablished as an opportunity to debate among thebeds as well as damages to fishery in Miyako Bay,

residents, Shiogama City and Miyagi Prefecture andandsharing facilitation of the debates (Figure-3.3.15.5).

rehabilitation of eelgrass beds at "Rehabilitation from

asked

for

technical

supporttowardthethe Great Eastern Japan Earthquake - the Hearing of
fresh voices along the Coastal Area in Iwate

Image shared at the forum(1) Considerations fordisaster prevention○ To plan to complete in FY2015 (To put priority on disasterprevention and consider the work period).
○ Revetment height sets at 3.3m above sea level.
Wish that escape stairs(3) Considerations for the future and chutes be aligned at
a proper interval taking
The hill and tower for refuge shall be into consideration theplanned with integral considerations properties of refugees.
of not only evacuation assumption,
facility scale and location probability,
but also the plants to assist thewater amenity.
A plan shall be considered onvitalization and natural conservationin Kitahama area (coordination witha special tourism zone).
・ Wish that people can safely
approach the waterfront witha stair type tideland etc.
・ To change the height ofstairs may affect living
creatures.
・ Require attention signboardson the stairs.
・ Examination of a facility like achute assuming the usage ofcanoe or kayak

Wish that spaces will bealso improved for use of
emergency supplies
transport (heliport,
mooring)

Prefecture -" hosted by the Ocean Policy Research

For basement at the erect part, wish
that piles will be driven in to the rockfoundation to avoid subsidence.
Regarding the crest width of seawalls
for tsunamis, require considering theutilities (vehicular traffic, use by
persons)

Foundation (OPRF) on October 19, 2011.
NILIM conducted an independent survey on thebottom sediment and eelgrass beds (February and9)October, 2012) , conveyed the situations, andRequire to discuss use
rules (such as fishing)requested cooperation to the NPO groups having
Require to consider the type ofliving creatures including
beach plants to be settled aswell as its management, withreference to the old scenes in
Kamaishi coast.
Require occasions for suchdiscussions.

Require discussions on the
management (such as dust
guard fences)

given cooperation at the eelgrass summit etc. In April
2012, "the Project for Bond of Revival Connecting the
Eelgrass

Beds

Restoration,"

which

is

regional(2) Considerations for theenvironment and usage

collaboration promoting work by the Seven-Eleven

Wish to improve as a hybrid-type
gentle slope revetment withartificial tideland.

Foundation, was inaugurated as a cooperative project
for the NPO entities tackling eelgrass revival

Figure 3.3.15.5 Memorandum Summarizing

throughout the country. NILIM has cooperated in the

Discussion Results at the Forum Regarding the

project, provided survey data, and assumed the

Rehabilitation Policy of Kitahama Revetment

operation of a workshop for the project.
The project held the first workshop and a field(2) Miyako Bay

survey in May 2012 (in Miyako City) and the second

The closed-off section of Miyako Bay used toworkshop and technical guidance for revival of7)flourish eelgrass beds broadly , and has beeneelgrass beds in June 2012 (in Tokyo and Yokohama

supported the local fishing industry as rearing places

City), and investigated the future revival strategyof herring. The Consociation of Seagrass Beds and(Figure-3.3.15.6).

303

“Result of sediment analysis in Miyako Bay”
Tomonari OKADA, NILIM
・ It is assumed that a strong mixing power and tractive power would have been generated by a break of thetsunami, followed by generating a bottom sediment move and deforming the bottom sediment.

Form a hotspring in the head of the bay (the second wave)(http://www.youtube.com/watch?v=KpqRWEDx4Pc)

20

20

n=3

% 10

- Modal particle size: 500-1mm- Major particle size: 20μm-3mm- Spread of particle size distribution: large- Coarse sand with silt and fine sand

g 77

% 10

0

10
1

100
2

1000
3

5

10
1

0

4

100
2

1000
3

Odanohama
Beach 1-1

4

- Modal particle size: 200-300μm- Major particle size: 100μm-3mm- Spread of particle size distribution: medium- Fine sand with coarse sandHanokihama
Beach2-2 2-1

Gravel3-1

Hachinokihama
Beach- Gravel of 3mm or more

There seems to be little affection for growing
39.595eelgrass despite including an amount of coarse
sand fraction

6-2

Large portions of coarse
sand and gravel

6-1

0

Horiuchi

4-1

10
1

0

1-2

Particle(μm)( m ))l og(G
rainsizesize

Particlem）( m) )粒径（l og(Grai
nsizesi (μm)
ze

g 76

% 10

Large portion of coarse sandCoarser than adequate

0

0

n=2

15

5

5

Tsunami Height in the head of the bay: 7-11m→shallow water depth (below 5m)→Wave with broken waves→Great tractive power→Move of bottom sediment, topographic
deformation, vanish of eelgrass

20

n=2

15

g 75 39.605

15

100
2

1000
3

4

og( Particle
Gr ai nsize (μm)
- Two modal particle sizes: 10-20μm and 1001000μm- Major particle size: 3μm-1000μm- Spread of particle size distribution: large- Medium sand with silt and coarse sandA bit larger portion of coarse sand
There seems little affection for growing
eelgrass.

7-1

Kanehama
国土技術政策総合研究所

7

7-2
20

6-3

海洋環境研究室・Akamae area is a suitable area to

n=3

8-1

- Modal particle size: 200-300μm- Major particle size: 40μm-1mm- Spread of particle size distribution: small(uniform particle size)- Fine sand

15

5-13

5-12

Suitable for growing eelgrass

5-11

% 10

5-5 5-2

5-9
5-10
5-14

5-6

g 71

5-4

5-1

5-3

Kamagasawa

5-7
5-8

5

0

regrow eelgrass from the viewpoint of
the bottom sediment・There are lots of gravel fractions in
Hanoki (Are the right spots localized?)・There is an area accumulating silty
soils

0

39.585n=4

20

141.945

g 72

15

% 10

20

n=4

15

141.955

10
1

100
2

1000
3

(μm)( m ))l og( Particle
Grainsize
size

4

10
1

100
2

1000
3

0

4

10
1

3
1000

4

A bit larger portion of silt
Muddier than the adequacy

0
0

2
100

- Two modal particle sizes: 10-20μm and 1001000μm- Major particle size: 3μm-500μm- Spread of particle size distribution: large- Fine sand with silt

5

0
0

1
10

size
(μm)
l og(Particle
rain
141.975

141.965

g 74

% 10

5

0

n=6

15

g 73

% 10

5

20

100
2

1000
3

4

Particle(μm)( m ))l og(Gr ainsize
sizeParticle(μm)
l og(G
rainsizesi ze( m ))→ A change of stream by structures (such as breakwaters) should be focused on
9)

Figure 3.3.15.6 Provided Information at the Second Workshop
In the area, the reconstruction support project forand the pre-examination of revival measures tosato-umi (Ministry of the Environment, MOE), has

handle when needed.

started to create the sato-umi reconstruction plan
including the revival of eelgrass beds and established(3) Ofunato Portthe development support committee for the sato-umi
reconstruction

plan.

The

chief

of

the

Ofunato Bay has been worried about environmental

Marinedeterioration inside the bay by breakwaters at the10, 11)

Environment Division and the research officer forbaymouth for a long time.

In December 2011, the Water Quality Control

Advanced Port Technology of NILIM joined theobserver,Measures Study Committee regarding Breakwater

respectively, and play a coordinating role with local

Diffusion at the Baymouth was established. In order tostakeholders for working together with NILIM'srecover the devastated breakwater at the baymouth ofinvestigation and the Project for Bond of Revival

Ofunato Bay, the committee was determined toConnecting the Regeneration Activity of Eelgrass

discuss

Beds at present.

considering the water quality inside Ofunato Bay as

committee

asamember

and

an

the

measuresofseawaterexchange

In the area, a newly-recruited seedling colony has

well as to ensure protective effects against tsunamis

now already been found as well as the remaining

and the stability of the breakwater when hit by aeelgrass beds, and the necessity of introducing

tsunami.

prompt active revival activity has been identified as

Environment Division of NILIM joins as a member andlow. We have been conducting continuous monitoring

attended the meetings on February 13, 27 and March

304

Currently,

the

chief

of

the

Marine

16,

2012,

respectively,

and

has

conducted

August 6 and September 30, 2011, respectively, andunderstandings of the current situation of Ofunato Bay

has made repeated investigations.

and investigation of measures for seawater exchange.
(5) Tokyo Bay(4) Soma Port and Onahama Port

In

Tokyo

Bay,

damages

occurredincluding

An explanation was provided on the situation ofsubsidence and inundation in the closed-off section ofseaweed beds in Misaki Area around Onahama Port

the Bay in and around Ichikawa City and Urayasu City,in November 2011 (Figure-3.3.15.7). This area hadand collapse of laver fences or drifting ashore ofbeen pointed out for a long time in that accumulation

spillage oil in and around Sanbanse or Banzu

and movement of the sand would relate to a

Tideland. Until the spring tide in May 2011 just after

degeneration of the surrounding rocky seaweed beds.

the Earthquake, the possibility of broad subsidence

Seaweed colonies after this tsunami were said tosuch as unusual disappearance of the tideland was

have

the

pointed out. On the other hand, however, in May 2011,

phenomenon was inferred from the effects of sandan abnormal tide level that surged by 10-40 cm

movement or boulders by the tractive power of theoccurred broadly on the Pacific coast because of antsunami. Conducting information exchanges wasoverlap of siphoning with the cyclonal passage anddetermined again after the results of the ongoing

the following wind drift. Thus, NILIM could not reject

seaweed survey were submitted.

the possibility that the surface elevation had induced

maintained

a

good

conditionandthe relative subsidence.
Ear shell farm in Misaki Area

As for the authenticity of these geomorphic changes,
in order to grasp the current situation of geomorphic
change (depression) in Sambanse which was referredSome fisheries point out the extension of 100m could be a cause.

to through the Sambanse ad hoc meeting in which the
The sand seems to move annually or seasonally, not to accumulate at aconstant speed, even though a tendency to partly accumulate sands can be
seen. Seaweeds for ear shell’s feed cannot be grown.

Survey line (image)(Environmental survey since 1981,
and the survey on sand move has
also started since 2008)

research officer for Advanced Port Technology
participated, an RTK-GPS survey was performed in

Consultants point out the cause may be derived fromthe existing structure of revetment.

the foreside of the Ichikawa Shiohama revetment
where a sand adhesion test was conducted on May

Aquamarine Fukushima, restarted on July 15, 2011
Lalamew, restarted on November 25, 201116, 2011. Even locally, NILIM verified little changes inthe sea bed near the revetment.
At the following ad hoc meeting held in August 2011,

Figure 3.3.15.7 Information from Hearings at

NILIM decided not only to spur on a broad topography

Seaweed Beds around Onahama Port (November

survey with other experts in Chiba Prefecture which is2011)

the governing body of the area, but also to support aneffective investigation by handling a part of the bottom

Following the detection of radioactive material fromsediment analysis at the NILIM. A wide-area sounding

the seabed sand in Soma Port, the investigative

investigation was performed from February 3 to 16,

meeting on the treatment of seabed sands containing

2012, and NILIM analyzed the particle size distribution

radioactive materials was established in June 2012.

with 22 samples gained from the investigation (Figure-The meeting is to conduct the development of related

3.3.15.8).

laws on the treatment of dredged sands generated by

Results of the sounding investigation showed 30cm

port construction works, the evaluation method ofof subsidence on average and 46% of area decrease

radioactive material concentrations in the dredged

at 0m depth or less (A.P. standard). As Funabashi

sand and the disposal method of dredged sands.

Seaside Park has still been an exclusion zone since

Currently, the chief of the Marine Environment

the damage of land facilities, a careful watch is

Division of NILIM attended the meetings on June 11,

required on effects that these changes in the305environment and utilization delivered to the ecosystem.

Frequency, Passingportionpercentage (%)

100
Frequency, Passingportionpercentage (%)

St.0-1Frequency(%)
Passing portion cumulation (%)

60
40
20
0
0.1

10

1000

0
10

1000

0

Frequency, Passingportionpercentage (%)

Frequency(%)
Passing portion cumulation (%)

60
40
20

0.1

10

1000

0.1

10
Particle size (μm)

1000

20

80

Frequency(%)
Passing portion cumulation (%)

60
40
20
0

0
0.1

10
Particle size (μm)

0.1

1000

10

1000

Particle size (μm)

100St.17-1
80

Frequency(%)
Passing portion cumulation (%)

60
40
20
0

100
St.18-1
80

Frequency(%)
Passing portion cumulation (%)

60
40
20
0

0.1

10

1000

Particle size (μm)

100St.19-1
80

Frequency(%)
Passing portion cumulation (%)

60

10Particle size (μm)

40
20

100

10
Particle size (μm)

1000

Frequency(%)

0.1

10Particle size (μm)

40

40
20

20
0

10

1000

0.1

10

Particle size (μm)

Particle size (μm)

1000

St.7-180

Frequency(%)
Passing portion cumulation (%)

60
40

100
St.11-1
80

Frequency(%)
Passing portion cumulation (%)

60
40
20
0

20

0.1

0
0.1

St.2-180

Frequency, Passingportionpercentage (%)

Frequency(%)
Passing portion cumulation (%)

60
40
20

0.1

10
Particle size（(μm)

1000

100
Frequency, Passingportionpercentage (%)

St.3-180

Frequency(%)
Passing portion cumulation (%)

60
40
20
0
0.1

10

Frequency(%)
Passing portion cumulation (%)

60
40
20
0
0.1
100
St.9-180

10Particle size (μm)

1000

Frequency(%)
Passing portion cumulation (%)

60
40
20

1000

0
0.1

10

1000

Particle size (μm)
Frequency, Passingportionpercentage (%)

Frequency(%)
Passing portion cumulation (%)

60
40
20
0
0.1

1000

St.8-180

St.4-180

10Particle size (μm)

1000

100

Particle size (μm)

10010Particle size (μm)

0Frequency, Passingportionpercentage (%)

1000

100

100

Frequency, Passingportionpercentage (%)

10Particle size (μm)

4020Frequency(%)
Passing portion cumulation (%)

60

0.1

Frequency(%)
Passing portion cumulation (%)

60

0.1

1000

80

St.21-1

80

Passing portion cumulation (%)
60

0

0
0.1

St.6-1100

St.20-1
80

1000

100

0

Frequency, Passingportionpercentage (%)

40

Frequency, Passingportionpercentage (%)

Particle size (μm)

Frequency(%)
Passing portion cumulation (%)

60

1000

St.15-1

Frequency, Passingportionpercentage (%)

20
0

0

Particle size (μm)

8010Particle size (μm)

100Frequency, Passingportionpercentage (%)

40

St.16-1

Frequency, Passingportionpercentage (%)

20

Frequency(%)
Passing portion cumulation (%)

60

100

20

0.1

80

Frequency, Passingportionpercentage (%)

40

St.14-180

40Particle size (μm)

Frequency, Passingportionpercentage (%)
20

Frequency(%)
Passing portion cumulation (%)

60

100

Frequency, Passingportionpercentage (%)

4080Frequency, Passingportionpercentage (%)

Frequency(%)
Passing portion cumulation (%)

60

0.1

Frequency, Passingportionpercentage (%)

Frequency, Passingportionpercentage (%)

Frequency, Passingportionpercentage (%)

80

St.13-1

Frequency(%)
Passing portion cumulation (%)

60

St.1-10.1
100St.12-1

St.5-1
80

100

0

100

100

Frequency, Passingportionpercentage (%)

80

Frequency, Passingportionpercentage (%)

Vertical axis: Frequency, Passing portion
percentage (%)
Horizontal axis: Particle size (μm)
Blue line: Frequency (%)
Red line: Red line: Passing portion
accumulation (%)

10
Particle size (μm)

1000

100
St.10-1
80

Frequency(%)
Passing portion cumulation (%)

60
40
20
0
0.1

10
Particle size (μm)

1000

Fig.3.3.15.8 Particle size distribution of bottom mud offshore Shiohama, Ichikawa City
Acknowledgements

Eastern Japan Earthquake in 2011," on the Web:In the field investigations, many facilities were

http://www.hira-provided by all the persons concerned in the Marine
Environment

andTechnologies

Division,birding.info/conservation/wetland/tsunami/

both3) The

Ocean

PolicyResearch

Foundation,

Onahama and Kamaishi Port Offices and Shiogama"Rehabilitation from the Great Eastern JapanPort and Airport Office of the Tohoku Regional

Earthquake - the Meeting Hearing fresh voices

Development Bureau and the Consociation ofalong the Coastal Area in Iwate Prefecture -," on

SeaweedBedandTidelandin

MiyakoBay.

the Web:

Cooperation in related data provision was made by Dr.

http://blog.canpan.info/oprf/archive/994

Teruhisa Komatsu, Associate Professor of the4) MORIOKA

Toru

and

FUJITA

Tsuyoshi:Atmosphere and Ocean Research Institute (AORI),"Rebuilding System to Improve Sustainability andthe University of Tokyo and the persons of theEnvironmental Efficiency," Proceedings of JSCE,

Tohoku National Fisheries Research Institute. We

No.587/VII-6, pp.1-14, 1998

here express our extremely deep appreciation.

5) KURIHARA Yasushi: "Tideland is Alive," Iwanami
Shinsho, 1980

References

6) Miyagi Prefecture Web Site, "Refresh Project in

1) Japan Project-Industry Council-JAPIC: "Report

Matsushima Bay":on the Diving Survey in Karakuwa Nishi-Moune,"

http://www.pref.miyagi.jp/kasen/kg_matsushima.h

2012

tml

2) HIRAIZUMI Hideki: "The Current Situation in the7) KOMATSU Teruhisa, Personal communication in

Wetland on the Pacific Coast after the Great2008."306

8) "The Consociation of Seagrass Beds and Tidal
Flats in Miyako Bay," on the Web:http://space.geocities.jp/miyakowannomoba/
9) OKADA Tomoya, YOSHIDA Jun, KAMIMURA
Satomiand

FURUKAWA

Keita:"Sediment

Conditions for Restoration of Eelgrass (Zostera
marina) in Miyako Bay," Technical Note of
National Institute for Land and InfrastructureManagement - NILIM, No.688, 2012
10) TOYOTA Masashi, HIBINO Tadashi, NISHIMORI
Dan'o, HOSOKAWA Yasushi and TSURUYA
Hiroichi: "Characteristics of Water Quality andCurrent Field around the Tsunami Breakwater inOfunato Bay during Summer," Technical Note of
the Port and Harbour Research Institute, No.938,
199911) OKADA

Tomonari,

NAKAYAMA

Keisuke,

MIYANO Masashi and FURUKAWA Keita: "The
Effect of Tsunami Protection Breakwater on
Concentration of Dissolved Oxygen in an
Enclosed Bay," Technical Note of the Port andHarbour Research Institute, No.1004, 2001

307

3.3.16 River Environment

introduced regarding the impact on the riverine(1) Introduction

estuaries by the tsunami focusing on results from the

The Great East Japan Earthquake, which occurred

survey at the mouth of Kitakami River in March 2012,

on March 11, 2011, inflicted not only enormousalready about one year after the Earthquake . This isdamages on the Pacific coastal areas in the Tohoku

just a quick report because the post-tsunami

region but also large impacts on the naturalenvironment is still in the stage of recovery from anenvironment on the coast.

enormous disturbance.

4)

A noticeable impact was observed in the riverine
3)(2) Outline of Investigation Area and Method

estuaries. In the Kitakami River, for example, thehabitat of reed communities was greatly changed by a

The Kitakami River is a class A river with 249km oflarge topographical change (Figure-3.3.16.1). In theriver length and 10,150km of catchment area, andNatori River, the vegetation in the riverine estuaries,

the present brackish water area was formed by thewhich had been observed in the past, disappeared

primary improvement work conducted from 1911 to

and worries have arisen about impacts on the1935. During the primary improvement work ofenvironment in riverine estuaries by the Earthquake

Kitakami River, an excavation work was done from

(Figure-3.3.16.2).

the Yanaizu area to the Iino-gawa area (at near 15 to

2

25km of river distance-marks), a channel was
replaced from the old Kitakami River to the Oppa
River and widening of the river course of Oppa River
was conducted by excavating the river course. At theupper end of the brackish water area, the final baffling
かつての北上川河口部ヨシ原

was performed with the Kitakami Barrage (17.2km)

震災後のヨシ原(H23.10.12.撮影)

placed in service in 1979. The brackish water

Figure 3.3.16.1 Changes in Reed Beds at the Mouth
1)of Kitakami River (Before: left, after (Oct. 12, 2011):

environment possessed a good landscape and wasright)

selected as "the Scene of Sound in Japan Best 100"by the Ministry of Environment as communities ofCarex rugulosa grew naturally around the riversides
and wide reed communities were maintained at thedownstream including the estuary.
The area for this survey ranged from 0kp (kilometerpost) at the mouth of Kitakami River to 17.2kp at
Kitakami Barrage, as shown in Figure-3.3.16.3, andthe synoptic and detail surveys were conducted on
March 2 to 4 and March 4 to 9, 2012, respectively.
The surveyed items were topography of the river

Figure 3.3.16.2 Impacts at the Mouth of Natori River

course, and vegetation and sediments inside the river2)

Before (left)/After (right) the Earthquake

course.

Thus, evaluation from a scientific viewpoint was
conducted both to understand how large impacts suchas the tsunami or land subsidence would have an
influence on the environment in riverine estuaries andfor utilization as know-how when conducting disaster3)

rehabilitation and nature restoration .
In this report, findings from the investigations are308

Survey
Area

Ishinomaki
city
Sendai city

Kitakami riv.

Kitakami Barrage（17.2kp）

Iino-gawa Br.

Figure 3.3.16.3 Map of Survey Sites at the mouth of
Kitakami River

Figure 3.3.16.5 Distribution of Vegetation (Reed
Community) after the Earthquake (March 2012)(3) Impact on Topography of River Course
An example of the river crossing of Kitakami River

The river terrace from point 2kp to 9kp was coveredpre- and post-devastation is shown in Figure-3.3.16.4.

with vegetation before the Earthquake, which included

The line of 2011 indicates the cross section after thereed communities in the main and salt marsh

devastation and the impact by land subsidence wasvegetation or Amur silver-grass communities in higher

adjusted by adding 0.601m of elevation.
1995
H7

2002

H14

places in the marginal area of the river terrace.

2010

In the post-devastation survey, most of the2011 (after)

H22

H23

14
12

vegetation observed was reed communities, and a

5KP

Elevation (m)10new small-scale salt marsh vegetation community

8
6

was found only at point 6.5kp.

42

It is estimated that impacts by the tsunami would

0-2

spread at point 0 to 9.4kp on the right bank and 0 to

-4
-6
-100

0

100

200

300

400

500

600

8.8kp on the left bank, respectively, judging from

700

Cross sectional distance (m)vegetation disappearance and the existence of

Figure 3.3.16.4 Example of Changes in the Cross

sediment by the tsunami. Particularly, in the island

Section Topography of the River (5kp)

near point 2kp that may have been greatly damagedby the tsunami, most of the pre-devastated reed

As an overall trend, no significant changes in thecommunities disappeared and only some parts

shape of the river crossing have been observed

remained on the mounds in the marginal areas (Seethough the river channel was homogenized in general

Figure-3.3.16.6).

as if small mounds were excavated and accumulated

However, it is considerable that it was easy toin the hollow.

observe the reeds remaining in the above-groundparts even after withering but impossible to find the(4) Result of Vegetation Survey Involving Reed

species easily losing their above-ground parts or

Community

those with small amounts, because of the periods for

1) Result of Synoptic Survey

the synoptic survey and its implementation in winter.

At first, changes in vegetation communities were

2) Result of Detail Survey

grasped by the synoptic survey on vegetation. The

A detail survey was conducted on the vegetation

vegetation distribution ranging from point 2kp to 9kp

and sediment at point 2.4kp and 6.4kp, respectively.

where the vegetation largely changed after the

Point 2.4kp is considered as the representative

Earthquake is shown in Figure-3.3.16.5 (the range

location where impacts on erosion and sediment by

indicated by the yellow hatching).

309

the tsunami as well as on the change in salinity by thereed community was observed as a vegetation type.

subsidence could be great and point 6.4kp as a

Others remained as open water and natural barelocation where the impact by salinity could be smalllands. Most natural bare lands are thought to be an

despite great impacts by erosion and sediment by theopen water place when the tide level is high. The reedtsunami.

community was observed at a relatively higher part ofthe elevation level along banks or channels, and the① Point 2.4kp

growth condition marked "Good" in the area which did

Aerial photographs before and after the Earthquake

not submerge at full tide, and "Slightly Bad" or "Bad"are shown in Figure-3.3.16.6. In the detail survey areain accordance with lowering the elevation level. Thereat point 2.4kp in the right photo, only reed

was little vegetation in the center of river terraces.

communities were observed as a vegetation type.

Furthermore, in the vegetation map created in 2008,

Others include open water and natural bare lands,

the part with the high elevation level along the channel

and places with a high tide level become surface

was a salt marsh vegetation community, but had

water in the most natural bare lands. The reedchanged into a reed community after the Earthquake.

community was observed in the marginal area or in

There was an approach lane of vehicles upstream

the central mound part with approximately 30cm offrom the detail survey area, and a community of Carex

relative elevation on the island, and the growth

rugulosa was found along the lane. The Carex

condition marked "Good" in the area with a relatively

rugulosa was observed with its recovery at point 6.4kp

high elevation, and "Slightly Bad" or "Bad" in lower

during the survey in June 2012 despite the small

areas.

amount identified.

Furthermore, in the vegetation map created in 2008,
communities of Amur silver-grass or Carex rugulosa(5) Impact on Reed Beds by the Tsunami Sedimentwere established in the mound area, but theseand Subsidence

communities could not be determined in this survey.

1) Synoptic Survey of Tsunami Sediment

The center of the island was covered with whole reed

Sediments by the tsunami were widely observed oncommunities in 2008, but they have disappeared.

the river terrace after investigation of the tsunami
sediment in the survey area during the synoptic② Point 6.4kp

survey. Figure-3.3.16.7 shows the thickness.

In the detail survey area at point 6.4kp, only the

The tsunami sediment was deposited thickly on the【震災前 H20】【震災後 H24】

Before (2008)

After (2011)

Figure 3.3.16.6 Vegetations with a Focus on the Reed Community Before and After the Earthquake (near point
2.4kp)

310

river terrace of both banks from point 5.0 to 10.5kp,

in Figure-3.3.16.8. Each mark indicates the place as

and, among them, the sediment was thicker fromfollows; ○: place with sprout growth, X: without sprout

point 5.0 to 7.0kp with 23cm at the thickest bed (at thegrowth.

synoptic survey). The sedimentary cycle whichindirectly shows the number of tsunami attacks wasLess sedimentation& high elevation

observed by up to four times at point 5.0 to 7.0kp after

1.2

estimating from grading structures.
On the other hand, the thickness of the tsunami

Thicksedimentation

1.0

sediment decreased downstream from point 4.5kp.
0.8

Elevation (m)The reason may be considered that a flow wasdisturbed by the collision of a run-up wave and adown-rush on the tsunami invasion, but the details areunclear.

0.6
0.4

Also, upstream from point 11.0kp, no tsunami

Low elevation &thick sedimentation

0.2

sediment was observed. The detailed cause isunclear though this may have been caused by a

0.0

decrease in the force to drag the sandy sediment and

0

10

20

30

40

reduce the run-up speed of the tsunami, or by some offour tsunamis occurring without arrival to the place

Figure 3.3.16.8 Impact on Reeds by the Elevation

though detailed causes are unknown. The river

Level and Bed Thickness of Tsunami Sediments

terracedownstream

from

point

10.5kp50

Sedimentation thickness (cm)whereremarkable tsunami sediments were observed was

At point 2.4kp of the island, reeds could be seen at

below the elevation level of 1.0m and lower than theapproximately T.P. (or Tokyo Bay mean sea level)maximum tide level.

0.4m or higher, and not below T.P. 0.4m. This may be
due to an inhibition of growth by the salinity and

Sedimentation thickness (cm)sediments.
At point 6.4kp of the river terrace on the left bank,each site is at T.P. 0.4m or higher, but reeds could not
be found in all sites. Regarding the place where reeds
could not be found after the Earthquake in spite of theKp (km)T.P. above 0.4m, some characteristics were observed

Figure 3.3.16.7 Thickness of Tsunami Sediments onon thick tsunami sediments as well as the existence of

the River terrace

reed rhizome in a deep position before theEarthquake. In spite of the bad growth condition,2) Result of the Detail survey for Tsunami Sedimenthowever, reed growth from the rhizome in greatly

and Reeds

deep positions was observed according to the location.

Possible impact factors on reeds in the riverine

The recovery from the rhizome seemed to depend on

estuaries are considered as a change in the elevationindividual differences.

level or salinity with the erosion by the tsunami or
ground subsidence, or burial on land of tsunami

3) Changes in the Ground Level Before and After the

sediments. Summarization was performed in the

Earthquake and the Vegetation

relation between these factors and the reed.

① Point 2.4kp

Relations among the elevation levels at point 2.4

The states of the ground level and the vegetation

and 6.4kp, bed thickness of tsunami sediments andwere summarized. Regarding vegetation changes in

the presence or absence of the reed are summarized

the detail survey area at point 2.4kp, the summarized311

results including a change to the natural bare land are

In addition, vegetation such as other salt marsh

shown in Figure-3.3.16.9. The vertical axis indicatesvegetation

the elevation level, and the horizontal axis indicatescommunities were not observed in this investigation.

the area by elevation level (the number of 5m x 5m

In the future, however, it is sufficiently possible that

grids settled in the survey area).

other vegetation will be established by succession ofcommunities

and

Amur

silver-grassentering vegetation or ingression of seeds orindividuals.

Elevation (m)Elevation (m)

Bare
Reed
Amur silvergrass
Carex

these

processes

is

also

desirable.

Max. tide levelMax. tide level

Studying② Point 6.4kp

Bare
Reed
Amur silvergrass
Carex

Regarding vegetation changes in the detail survey
area at point 6.4kp, the summarized results including
a change to the natural bare land are shown in Figure3.3.16.10 as well.

After (2011)

Figure 3.3.16.9 Relationship between the Elevation

Bare
Reed
Amur silvergrass
Carex

Earthquake in the Detail Survey Area at Point 2.4kp

Max. tide level

Elevation (m)Level and the Vegetation Before and After the

For the vegetation before the Earthquake, although

Bare
Reed
Amur silvergrass
Carex

Elevation (m)Before (2005)

Max. tide level

the reed community was dominant from the elevationlevel of 0.0 to 0.5m, evidence was observed regarding
mixinggrowthswithasalt marsh

vegetation

Before (2005)

After (2011)

community (mixture of the Carex rugulosa) at 0.2m or

Figure 3.3.16.10 Relationship between the Elevation

higher and with an Amur silver-grass community at

Level and the Vegetation Before and After the

0.4m or higher, with domination by other vegetation

Earthquake in the Detail Survey Area at Point 6.4kp

than the reed community at 0.6m or higher. No
The vegetation before the Earthquake consisted

vegetation was found below the elevation level ofmainly of the reed and salt marsh vegetation

0.0m.
The elevation level with a high frequency ranged

communities (mixture of the Carex rugulosa). Looking

from certain 0.2 to 0.4m before the Earthquake, but

at the peaks of altitude at which they appear, manyfrom certain -0.5 to -0.2m after the Earthquake, whichsalt marsh vegetation communities were observed at

was lower by 0.6 to 0.7m. Considering the rivera bit higher level because reed communities ranged

terrace would have settled down in whole, an impact

from 0.4 to 0.6m and salt marsh vegetations from 0.5of the erosion by the tsunami is possible because of a

to 0.8m. The proportion of Amur silver-grass

disappearance of the vast vegetation bed at aroundcommunity kept high above the elevation level of 1.0m.
The vegetation observed after the earthquake isthe elevation level of 0.0m.
At present, a reed community is found in the area

only reed communities. The high frequency of theabove the elevation level of 0.0m. In the area below

elevation level ranged from 0.2 to 0.3m, and the same

0.0m, however, the natural bare land remains as it

as the case of point 2.4kp, frequency distributions

was, or the condition has been bad in spite of growing

were polarized unlike the situation before thethe reed. For the future, in order that the reed

Earthquake.

community can be developed at around point 2.4kp as

Like point 2.4kp, no vegetation has been found inbefore, the elevation level should be considered being

the area below 0.0m. In the area below 0.3m, reeds

above 0.0m.

are sprinkled and the growth condition is bad.

312However, as not only the terrestrial part but also

References

situations of survival or growth of reed's rhizome have1) The Website of Kitakamigawa-karyu River Office,been confirmed, the possibility for recovery is

Tohoku Regional Bureau, MLIT: "The Proceeding

somewhat positive for the future.

Summary of the 7th Conference with Academics

In a part, the Carex rugulosa and Carex kobomugi

on the River Development of Reservoirs along thehave been found. Vegetations like other salt marsh

Kitakami River. Material-1: Overview Document

vegetation and Amur silver-grass communities haveon the River Development of Reservoirs along the

not been verified, but it is sufficiently possible that

Kitakami River (Proposed Change) (in Japanese),other vegetation will be established by succession of"http://www1a.thr.mlit.go.jp/bumon/j73101/homep

vegetation or ingression of seeds or individuals in theage/kawa/seibi_keikaku/dai7/dai7_03.pdf

future. Grasping these processes is also desirable.

(Accessed on December 12, 2012).
2) The Website of Sendai Office of Rivers and(6) Lessons for Nature Restoration

National Highways, Tohoku Regional Bureau,

The reed community at the mouth of Kitakami River

MLIT, "The 7th Conference with Academics on

was largely eroded by the tsunami and the area has

the River Development of Reservoirs along thehalved. In particular, the vegetation bed was lowered

Natori River. Material-1: About the Change of theby land subsidence. And at point 0kp to 4 or 5kp

Development Plan of Reservoirs along the Natori

where the salinity increased more than that before theRiver

Earthquake, it seems difficult to grow the reed due to

http://www.thr.mlit.go.jp/sendai/kasen_kaigan/nah

the impact of salt levels at present. A way to raise ai/nat_kondan/07/0101.pdf

river terrace may be effective to get rid of these

December 12, 2012).

impacts.

(inJapanese),"(Accessedon3) ENDOU Maremi, ONUMA Katsuhiro and AMANO

On the other hand, even though impacts by salt

Kunihiko, "Analysis of the Impact on Estuarine

contents are not fatal upstream from point 5kp, theVegetation from Sinking Ground by the 2011 Off

impact by tsunami sediments seemed enormous. In

the Pacific Coast of Tohoku Earthquake," Journal

this section, gradual restoration from the reed bedof River Engineering, Vol.18, pp.53-58, 2012,

remaining in the marginal part or upstream seems to

http://www.nilim.go.jp/lab/dbg/pdf/201206_53-

be realizable in the long view. But prompt restoration

58.pdf (Accessed on September 30, 2012).

is desirable as there is a region where reeds are4) NAKAMURA Keigo: "Impacts of the Tsunami ofutilized for industries. Fortunately, under tens of

the Great East Japan Earthquake on Riverine

centimeters of tsunami sediments, it is sufficiently

Estuary, a case study: the Kitakami River Mouth,"possible to promote the restoration of reeds by a

Kasen (in Japanese with English abstract), No.

simple method of turning over the ground as the pre-795, October 2012, pp.41-46, 2012devastated reed rhizome remain. This needs a quick
treatment as the life of the rhizome is limited. However,
the environment in habitats or nursing areas for
precious animals and plants must not be devastatedonly because of rushing ahead with reed restoration.
A method should be implemented with as small an
impact as possible while grasping the current situation.
For example, it is a probable way to restore a reed
bed at intervals by utilizing the underground stem andto develop it from the area.

313

3.4 Research Study
3.4.1 Orientation of Research Activity for
the Future Recovery

not be assumed" would be especially important in

After the occurrence of the Great East Japan

1) Issues to be bolstered on the aspects ofthe future studies and confirmed the following issues
to be examined:

Earthquake, in conducting technical assistance for

evacuation

other parties concerned and regional development

non-structural improvements and the remedy

bureaus in the Ministry of Land, Infrastructure,for "Saving human life."

andissuesforconsidering

Transport and Tourism (MLIT), the National Institute2) Concentration of applicable technologies andfor Land and Infrastructure Management (NILIM)

various plan options and ideas in order tohas recognized it as an important responsibility as asecure the facility function and recover it

research institute to make progress in necessary

quickly,

studies in advance, looking at the issues that

3) Non-structural preparation for life rebuilding

various unexpected natural disasters would bringand life support after the disaster,

down on the country from a medium- and long-term4) Examinations on "reconsidering the vision of

viewpoint, in consideration of the damage from theacceptable

Earthquake. In addition, while looking ahead toperformances and acceptable risks for facilities

social changes including aging and depopulation,

against external force," "Expansion of the

NILIM has also realized it is essential to consider the

viewpoint of planning theory" and "Widening theideal future vision of the country against natural

cross-cutting viewpoint."risks

required

and

limit

disasters, define the challenges to tackle, and study

Also, the "Working group (WG) on the study

the direction for issue solution by looking oversession for risk management" was launched on

issues which could occur due to an inconceivable

March 30, 2012, as a study session at the practicalnatural disaster, from various fields and viewpoints.

level in order to seek possibilities for practically andAs a result, the "Study session for risk

concretely trying issues in each research section,

management" was established on October 14, 2011,

problem consciousness, the start and conduct ofwhich is comprised by directors of NILIM andresearches and additional alignments with theresearch directors in related fields. In the session,arguments through the study sessions.

orientations for recognition and solution of subjects

The WG set to conduct "Information sharing of theagainst inconceivable natural disasters by the NILIM

progress of studies on various disasters regarding

were settled for discussion, alongside gathering

unforeseen external forces and their evaluation" andknow-how in various fields. The main themes in"Share and discuss the progress and circumstances

discussion at the time of the inauguration of the

conducted in each research from the viewpoint ofsession were as follows:

risk management," which were carried out during

1) Challenges that emerged on the Great East

the second meeting on June 13 and the third on

Japan Earthquake,

September 20, 2012, respectively.

2) Challenges that should be tackled with regard

In parallel with the comprehensive discussions in

to various natural disasters beyond existingthese study sessions, the next researches werepredictions,started, as an individual research project. an IT and

3) Directionality for the solution of former

information section regarding disaster prevention

problems?.

and reconstruction projects are summarized in

At the second session on November 14, 2011,section 3.4.5, and, as well, the research orientations

intensive arguments were continuously conducted

are described regarding "3.4.2 Study on theon the three subjects above mentioned. Therefore,

Systems

we recognized that "Preparation for an external

Mitigation from Tsunami", "3.4.3 Research on theforce more than the limit performance which could

Disaster-structured Supporting Technologies in314

ofMultiple

DefensesandDisasterCoastal Cities" and "3.4.4 Study on the Risk andconsidering the Great Earthquake as a specific

Crisis Management Strategy for Excessive andresearch project.

Multiple Actions of Natural Disasters" in relation tothenewly-launchedprominent

investigations315

3.4.2 Research on Multiple Defense
Systems and Tsunami Disaster Mitigation

evacuation and crisis management, and measures to(1) Introduction

and other methods.

improve safety and mitigate disaster through land use

The Great East Japan Earthquake, which occurredon March 11, 2011, triggered a massive tsunami of a

Research on Multiple Defense Systems and Tsunami Disaster Mitigation

kind said to occur only once every 500-1,000 years,② Setting method of external forces of Level 1 and Level 2 tsunamis

far in excess of the external force that coastal
protection infrastructure was designed to withstand.

④ Evaluation of tsunami hazard on lands
Examination of disaster reductions suchas flood control

Including both confirmed dead and missing persons,③ Research on tsunami protection along
the coastline

this disaster claimed almost 19,000 lives.
In

terms

of

the

policyforrecoveryandreconstruction in light of this major tsunami disaster, it
was proposed that an approach be adopted involving
the establishment of a two-level external force system,
based on Level 1 tsunami (tsunami protection level)and Level 2 tsunami (tsunami disaster mitigation level).

⑤ Improvement of safety by evacuation, risk
management support and land use

Figure 3.4.2.1 Content of Research

The proposed approach would focus on protecting
human life and property from comparatively frequent
Level 1 tsunami, using coastal structures, andAs well as using the outcomes of this research to

implementing disaster mitigation aimed at protecting

support recovery and reconstruction in the aftermath

human life by means of multiple defenses centered onof the Great East Japan Earthquake, we aim toevacuation in the case of Level 2 tsunami. In theensurereport by the Central Disaster Prevention Council's

countermeasures in regions where it is feared that

Committee

tsunami will occur in future, such as the Pacific coastforTechnical

Investigation

on

that

they

are

reflected

intsunamiof West Japan.

Countermeasures for Earthquakes and Tsunami
Based on the Lessons Learned from the "2011 off the(2) Support for Recovery and Reconstruction

Pacific coast of Tohoku Earthquake", A Level 2
tsunami is referred to as the largest-class tsunami,

As one of the objectives of this research is towhile a Level 1 tsunami is referred to as frequently-

support recovery and reconstruction in the aftermath

occurring tsunami.

of the Great East Japan Earthquake, researchoutcomes

The research conducted in this project consists ofobtainedbyurgentsurveysarethe five studies shown in the diagram below (Figure

progressively being published and reflected in

3.4.2.1). (i) Summarizing lessons concerning tsunami

relevant measures. The main research outcomes arecountermeasures gained from surveys of the damage

introduced below.

resulting from the Great East Japan Earthquake and1) Method of Setting Design Tsunami Water Level

new findings concerning the damage caused by

See 3.3.5(1).

tsunami; (ii) summarizing past tsunami trace data andsummarizing techniques for using tsunami inundation

2) Guidelines on Tsunami Inundation Simulations

simulations to set Level 1 and Level 2 tsunami; (iii)

See 3.3.5(6). As well as being able to conduct

developing structural methods that will make seawalls
forappropriate tsunami inundation simulations quickly,

formulating river plans that take into account the river

this will make it possible to ensure that differences dorunup of tsunami; (iv) studies concerning tsunami

not arise between engineers in terms of techniques

hazard evaluation in inland areas and the control ofand the setting of conditions.

morerobustandconsidering

techniques

inundation flow; and (v) studies concerning support for

316

3)

Provisional

Standards

Concerning

Structural

assumptions (districts expected to be flooded in theRequirements for Tsunami Evacuation Buildings

event of a tsunami and the depth of the waterSee 3.3.9(3). In addition, in the process of

resulting from this) based on tsunami inundationconsidering this matter, it was necessary to makesimulations. In the process of that, the largest-classestimates for each of the damaged buildings

tsunami is assumed, based on the results of basic

regarding the external force resulting from the tsunami,

surveys of past earthquake tsunami and earthquake

unlike in the case of analysis of damage from seismic

tsunami assumptions.

motion. However, there were areas where field

The tsunami inundation assumptions set on thesurveys alone were not sufficient to confirm thebasis

information required for estimating the relevant

information for effectively combining a range ofexternal force, so even within NILIM, researchers inmeasures, in the form of putting in place warning andthe River Department and the Building Department

evacuation systems, and regulations concerning landcollaborated in their deliberations on this issue.

use. This then forms the basis for the compilation ofofmunicipal

scientificplans,

knowledge

the

form

management

the

of

basic

tsunami4) Resilient Structures for Coastal Dikes

protection facilities, and the designation of caution

See 3.3.5(2) and 3.3.5(3).

zones and special caution zones.
Progressive revisions are being made to the(3) Creation of Tsunami-resistant Communities andGuidelines on Designing the Assumptions of Tsunami

Related Research

Inundation, which was compiled in February 2012,

From the tsunami resulting from the Great East

expanding upon the content of the Guidelines on

Japan Earthquake on March 11, 2011, we learned theTsunami Inundation Simulation referred to in (2) 2)

lesson that "there is no upper limit for disasters". Inabove and setting forth the standard procedures andorder to prepare for such large-scale tsunami andmethods

protect human life by all means, it is necessary toassumptions stipulated in law . Technical support iscreate tsunami-resistant communities

based onbeing provided in the same way as for the Guidelines

multiple defenses, which involves mobilizing both hardon Tsunami Inundation Simulation, by establishing aand soft measures.

consulting service. For further details, see 3.3.5(7).

fordesignatingtsunamiinundation2)

It is necessary not only to create tsunami-resistant2) Method of Setting the Standard Water Level

communities in the reconstruction of the disaster-

The standard water level is the water level obtained

afflicted areas, but also to promote this endeavor
Regional

by adding the rise in the water level (swell) resulting

Development in Tsunami Disaster (Act No. 123 offrom the collision of a tsunami with buildings and othernationwide.

Accordingly,

the

Act

on
1)

2011) was enacted in December 2011 .

structures, to the water depth stipulated in tsunami

The outcomes of this research project will be theinundation assumptions (this does not take into

techniques that will support this endeavor, and will beconsideration the effects of individual buildings). This

reflected in relevant standards. Figure 3.4.2.2 showswater level forms the standard for judging thewhattsunami-resistantnecessary height of evacuation areas and living areas

communities and the relationship between this andin Specified Buildings (social welfare facilities, schools,

the main techniques that will support this endeavor.

and medical facilities, etc.) in special caution zones.

isinvolvedincreating

The outcomes that have already been published as

In the tsunami inundation simulations used when

standards or guidelines are as follows.

setting the tsunami inundation assumptions referred toin 1) above, set up of water level at individual1)

Guidelinesfor

Setting

TsunamiInundationbuildings is not taken into account, as consideration is

Assumptions
Prefectural

given to the impact on buildings in terms of roughness
governors

settsunamiinundationin overall land use. The height of set up resulting from317

individual buildings can be calculated by taking
buildings into account as walls or topographic data.
However, there would be an endless amount of work
if calculations were made to take every case into
account when considering regional development anddeveloping regulations for buildings. Accordingly, we
have proposed a convenient, yet hydraulically-rational
calculation method based on the results of tsunami
inundation simulations. For further details, see
3.3.5(7) and the Report on Technical Review
Concerning the Regional Development in Tsunami
3)

Disaster . This calculation method was reflected in
the enforcement notice Concerning the Enforcementof the Act on Regional Development in Tsunami
4)

Disaster , dated March 9, 2012.

318

Content of the regional development in tsunami disaster

Important techniques supporting the left items• Evaluation of risk and safety with the maximum class oftsunami by sight frontage

Tsunami Inundation Assumptions

Setting method of the maximum class oftsunamiTsunami inundation simulation method

Promotion plan (community development)• Cooperation among public works

・・・(Disaster prevention facilities such as levees, tsunami protective facilities,
evacuation routes, evacuation facilities, parks, green space, disaster prevention
center facilities and land use relating public works)• Cooperation with local governments, prefectures and the national
government• Interactive cooperation of hardware with software
Transfer to an upland

Tsunami protective
facilities

Evacuation sites(upland)
Evacuation routes

Areas to be prevented
from inundation bytsunami protective
facilities

Risk communication method
Decision-making method
Evaluation method for evacuation
safetySafety checking method forbuildings against tsunamis

Special caution zones(Orange zones)

Promotion plan areas(Whole zoning)

・・・

Improvement of tsunami warning

Caution zones(Yellow zones)

Raising of housing lots

Calculation method for safe evacuation
space height (base water level)

Safety checking method fordeveloped lands against tsunamis: Managed techniques such as standards
and guidelines: Techniques to be expected concerning theexamination in the future(Red zones)

Figure 3.4.2.2 Details of the Regional Development in Tsunami Disaster and the Techniques to Support This
3) Technical Standards Concerning the Structure of

NILIM) examined the external forces, performance

Designated Tsunami Facilities, etc.

requirements, and verification methods that should be

See 3.3.9.5(3).

taken into consideration in the design of tsunami
protection facilities. For details of the results of their

4) Technical Standards for Tsunami Protection

deliberations, see 3.3.5(7) and the Report on

Facilities

Technical

Review

ConcerningtheRegional

3)

Development in Tsunami Disaster .

Tsunami protection facilities are disaster prevention
facilities newly positioned in the Act on Regional
Development

in

TsunamiDisaster.

5) Technical Standards for Specified Development

TsunamiActivities

protection facilities are facilities established inland toprevent the expansion of inundation as a result of a

The special caution zone (Orange Zone) is the zone

maximum-level tsunami having runup on land. This

within the caution zone (Yellow Zone: zone in which a

assumes that it is possible efficiently to put in place

warning and evacuation system has been put ininfrastructure such as small-scale mounds; suchplace) in which regulations require that Specified

facilities are not intended to be an alternative to

Buildings and development activities be made safe

seawalls that prevent actual tsunami on the coast.

against tsunami.

The Technical Review Committee on the Regional

Specified Buildings are social welfare facilities,

Development in Tsunami Disaster (Secretariat: Water

schools, and medical facilities used by elderly people,

and Disaster Management Bureau, City Bureau,small children, or those who are sick, for whom it is319

difficult to escape from a tsunami. Making buildings

face of a largest-class tsunami.

safe against tsunami involves securing living areas ata height that a tsunami will not reach, on developed
land and in a building structure that is safe even in the

Research Flows
Tohoku Regional Development
BureauDisaster-stricken prefectures, etc.

①Surveys (Damages, characteristics
and lessons)・ Tsunami traces ・Levee disaster
・Building disaster ・Topographic
change・Actual situation of evacuation

Research Reports• How the recent earthquake
occurred• How the recent tsunami occurred• How earthquakes and tsunamis in
the past occurredTechnical Investigation of the Central
Disaster Prevention Council'sCommittee
Japan Society of Civil Engineers, etc.

Regional actions• Prefectural Restoration
Investigation Committee• Local Governmental Restoration
Investigation Committee• Tsunami-resilient Promotion Plan
Livelihood Restoration• Rubble treatment• Transfer to an upland, Landuse control④Evaluation of tsunami hazard• Tsunami inundation simulation• Simple evaluation of accumulation volume

L1 Tsunami: Protection of human life and properties bycoastal protection facilities
L2 Tsunami: Human life protection by multiple protections
based on evacuation

Image picture on tsunami
inundation (L2 Tsunami)
Setting method of standard waterlevel (L2 Tsunami)• Hazard map manual for tsunamis andhigh tide• The optimal fault model viewing fromtsunamis• Investigation of tsunami sediment etc④Disaster reduction by the flood flow
control tower• Control by tsunami protection facilities• Embankment (Upland development)

Technical Investigation of the Central
Disaster Prevention Council's Committee
Committee of Atomic Civil Engineering of
JSCE, etc.

Technical standard of tsunami
protection facilities
Licencing permission forembankment, etc.

② Setting survey on tsunami external forces• Arrangement of trace heights by the past tsunamis• Standard method for tsunami inundation simulation• Arrangement by the Urban Planning
Department (House destruction curve, etc.)

Regional development in tsunami disaster

Surveys by various organizations andacademic associations such as 2011 Tohoku
Earthquake Tsunami Joint Survey Group

Report by the Technical Investigation of the Central Disaster
Prevention Council's Committee
Proposal by the Council for Social Infrastructure and the Council ofTransport Policy
Report by the Committee for Specific Theme on Tsunamis of JSCE

⑤ Evacuation and hazard management support⑤ Safety improvement and disaster reduction by landuse, etc.
• Standard revision regarding structural requirements
for refugee buildings• Tsunami inundation assumption system(Improvement of information reliability, security
ensuring of flood fighting corps)• Evaluation of evacuation security• Urban area improvement for disaster reduction

Setting method of the water depth of designed
tsunamis (L1 Tsunami external forces)
Tsunami inundation simulation guideline③ Protection of coastlines, etc.
• Levee disaster analysis• Structural improvement (resilient)• River plans that take into accountthe river runup of tsunamis

Standard revision for refugee buildings

Urgent proposal for restoration of estuary
barrages and floodgates
Urgent proposal for coastal facility restoration

Establishment guidance for disasterpreventive urban development plan

• How to alert the tsunami warnings (JMA)

Picture of the coast after restoration
Guidebook for Landscape Consideration in the
Reconstruction of River or Coastal Structures

Restoration and reconstructionin East Japan

Reflection to tsunami countermeasures inWest Japan, etc.

Figure 3.4.2.3 Flow Diagram of Research in This ProjectWithin the special caution zone (Orange Zone), it isto engage in wide-ranging deliberations concerning

possible to use municipal ordinances in the same way

not only tsunami engineering, coastal engineering,as described above in order to regulate construction

hydraulics, and hydraulic engineering, but also

and development activity to ensure that houses andgeotechnics and soil mechanics. The details areresidential land that are safe against tsunami arereported in 3.3.5(7) and the Report on Technicaldeveloped (Red Zone) .

Review Concerning the Regional Development in
3)

Similarly to the methods for setting standard water

Tsunami Disaster , and the outcomes were reflectedlevel and the Technical Standards for Tsunami

in a ministerial ordinance that entered into force on

Protection Facilities, the Technical Review Committee

June 13, 2012. In addition, as stated above, theon the Regional Development in Tsunami Disasterstandards in 3) are applied as standards for building

also considered techniques for verifying the safety ofstructures.

developed land against tsunami in the process of
specified development activities. As this involved6) Development of Evacuation Safety Evaluation

collaboration among multiple fields, it was necessaryTechniques

320

and

Urban

Development

Planning

Techniques for Disaster Mitigation

Accordingly, important tasks for the future include

From FY2012, as part of the "Research concerningcompiling a summary of techniques for setting

techniques to support the development of disasterassumptions concerning the behavior of various types

prevention structures in coastal cities" project, studiesof river structure, such as in the event of a riverare being conducted on urban development planning

embankment breach, with the techniques tailored totechniques based on evacuation safety and planning

different purposes, for example, soft measurestechniques for ensuring redundancy in the functions ofincluding urban development and evacuation.

disaster prevention bases (see 3.4.3).

Based on an awareness of this issue, the River
Division is examining the following matters.

7) Content of Future Deliberations in the Field ofRivers(i) Analytical Techniques Focused on River Tsunami

Following the recent tsunami, river tsunami have

In estimating river tsunami water levels and runup

been positioned as the focus of systematic measures,sectors, conditions are set in regard to such factors asalongside flooding and high tides. The basic policy

river channel shape (low-water channel or flood

and approach for this are set forth in Concerning

channel, mouth bars, river channel traits (bend or

Measures to Counter River Tsunami (September 2,

straight line), etc.), river bed evolution, embankment

2011; Notice from the Director, River Planning

overflow or breach, and river flow, but the changes

Divisionandthat occur in these conditions - for example, howManagement Division). Moreover, as stated inacutely these are expressed as fluctuations in the

3.3.2(2)-(6), the Committee has set forth its approachwater level - are not necessarily clear. This is a

to considering measures tailored to individual riverfundamental technique that is closely related to thestructures and hazard mechanisms. These advanced

structural design of river embankments, so as well as

new policies and approaches will be translated intodeveloping a more profound understanding of thisreality as measures focused not only on rivers

matter, it is important to reflect it in deliberations

affected by the Great East Japan Earthquake, but also

concerning tsunami countermeasures.

andDirector, River

Improvement

rivers nationwide, taking into account the attributes ofAccordingly, it has been decided to conduct a

individual rivers and tsunami conditions.

model experiment focused on a river tsunami, using a

In the process of conducting numerous rounds of

1/330 scale planar model of the Shin-Kitakami River.

deliberations about such measures and reflecting inIn the model experiment, various conditions aretheseresearch

altered systematically, including the river channel

conducted in parallel in a timely fashion, it will be vital

topography (including whether or not there is an

to ensure that surveys and calculation techniques

embankment breach), roughness, and input waveform

tailored to river and tsunami conditions are refined inof the tsunami from the estuary, and the water level oforder to improve the quality of measures, and thatthe river tsunami is then measured. Based on these

these are reflected in various relevant standards.

results, the impact of each condition on the water level

deliberations

theoutcomesofFurthermore, if the perspective is broadened fromis evaluated. Then, replication calculations of thesemeasures for river areas to include the creation of

results are carried out, and consideration is given todisaster-resistant communities, assumptions about

improvements to river tsunami analytical techniques

the flooding that would occur as a result of various

and methods of setting conditions that are moredegrees of "tsunami beyond the facility plan",closely tailored to the objective.

including the largest-possible tsunami, will form thebasic information for undertaking various deliberations.

(ii) Behavior of River Embankments in Relation to

It is surmised that the extent of the flooding could

Overflow in the Event of Tsunami Runupchange depending on the behavior of river structures

At the time of the recent tsunami, there were cases

when acted upon by tsunami beyond the facility plan.

in which the overflow from the river embankment

321

caused during the runup of the first wave of theregardingtsunami continued for up to ten minutes, with theincluding prior measures and emergency responses in

depth of the overflow water reaching 10m in somethe event of disaster - will be broadened to include

cases. Compared with the overflow experienced

complex disasters in the event of flooding occurring

during normal floods, the overflow during a tsunami isconcurrently with an earthquake, tsunami or slopecharacterized by the fact that a high flow velocity acts

failure.

disasterprevention

andmitigation-on the embankment during a short period of time.
Data concerning the recent tsunami, in relation to the(4) Conclusion

behavior of river embankments when acted upon by

Figure 3.4.2.3 shows the process via which

the tsunami in this way, are being gathered andresearch was conducted in this area. One of theanalyzed (see 3.3.3(1)). As a result, the research

objectives of the research is to support responses toteam has ascertained that the scale of levee bodydisaster and subsequent recovery and reconstruction,

erosion can change according to the extent of theso many research outcomes have already been

flooding within the area protected by the embankment

reflected in measures (see Figure 3.4.2.2 "Techniques(whether or not there is a water cushion).

already rolled out in standards and guides, etc.") In

We will continue to conduct deliberations aimed atconsidering

theirreflectionintsunamiaugmenting knowledge concerning such cases andcountermeasures outside the disaster-afflicted areas,

erosion mechanisms, but at the same time, for

it is likely that the items described in Figure 3.4.2.2 asexample, in the case of river embankments, we will

"Techniques for future consideration" will come to bealso examine ways of using knowledge about such

more important. Of these, the Urban Planning

matters as how to set the various conditions that affect

Department will commence a study during the current

the extent of flooding (including the tsunami water

fiscal year as part of this research project, focusing onlevel that causes embankment breaches, and thetechniques for evaluating evacuation safety. It is

locations and length of those breaches) in such a way

hoped that the outcomes of this study will become aas to make it possible to envisage a flood situation

technique that will support the creation of tsunami-

appropriate to the focus of deliberations.

resistant communities.
Moreover, Figure 3.4.2.4 shows the research(iii) Measures in Anticipation of Complex Disasters
Rivermanagement

infrastructurewasimplementation system for this project. With NILIM's

also

River

Department,

Building

Department,

Urban

damaged by the recent earthquake and tsunami, so

Planning Department, and Research Center for Land

rapid repairs were made ahead of the flood season.

andHowever, due to various constraints, these did not

implementing

necessarily restore the functions of this infrastructure

departments and projects within NILIM is being sought,

adequately, and aftershocks further increased theand findings are being shared among them. In

scale of the damage and the number of places

addition,

affected. We have responded to this situation byacademic societies, investigative committees, andaugmenting checks under normal circumstances, as

administrative bodies, NILIM is sharing its findings andwell as when the rivers are in flood, dealing withreflecting its research outcomes in various measures.

issues as they arise, which has enabled us to getthrough the flood season without any major problems.
Moreover, there have also been disasters since therecent earthquake and tsunami, including the floodingthat resulted from slope failure due to Tropical Storm
Talas in 2011.
In light of such events, the scope of deliberations

322

Construction

Management

bodies,working

in

as

the

main

collaboration

with

other

partnershipwithrelevant

Research implementation system (on October 16, 2012)

he Enforcement of the Act on Regional Develo• Cooperation with the Committee for Specific Theme on Tsunami of JSCE
• Committee for Technical Investigation on Coastal Countermeasures against Tsunamis• Coordination with relating to administrative sections of MLIT
• Reflection through supports relating to local restoration andTsunami Comprehensive
reconstruction
Project (Building Department)

pment for Tsunami Disaster Mitigation, March

NILIM• Environment Department

Project Research• Road Department(Coast Division and River
Division)• Research Center for
Disaster Management(Standards and Accreditation
System Division)

Cooperation• Coastal, Marine andDisaster Prevention
Department(JSCE etc)

Investigative
Committees, etc.

• Building Department(Bridge and Structures Division)(Flood Disaster Prevention
Division)(Earthquake Disaster Prevention
Division)

Academic Associations• River Department(River Environment Division)(Landscape and Ecology Division)(Coastal Disaster Prevention
Division)etc

Related sections of MLIT

• Urban Planning
Department(Seacoast Office of Water and Disaster
Management Bureau, Building
Guidance Division of Housing Bureau,etc.)• Research Center for Land
and Construction
Management

Prefectural and Regional
Offices(Urban Disaster Mitigation
Division and Urban Development
Division)(Construction Economics
Division)

Local Government related
Organizations
14

Figure 3.4.2.4 Flow Diagram of the Research
Implementation System for This Project
References
1) Act No. 123 of 2011, Act on Regional Develo
pment for Tsunami Disaster Mitigation, December 14, 2011
http://www.mlit.go.jp/sogoseisaku/point/tsunamibousai.html)
2) Ministry of Land, Infrastructure, Transport andTourism, Water and Disaster Management Bur
eau, Seacoast Office: National Institute for Land and Infrastructure Management, Coast Divisi
on, Guide to Setting Tsunami Inundation Assu
mptions (ver.2.00), October 2012
http://www.mlit.go.jp/river/shishin_guideline/bousa
i/saigai/tsunami/shinsui_settei.pdf
3) Technical Review Committee on the Creationof Tsunami-resistant Communities, Report on T
echnical Review Concerning the Creation of T
sunami-resistant Communities, January 27, 2012
http://www.mlit.go.jp/river/shinngikai_blog/tsunami
bousaitiiki/houkokusyo_120127.pdf
4) Enforcement Notice, Cabinet Office: Director G
eneral for Disaster Management; Ministry of La
nd, Infrastructure, Transport and Tourism: Director-General of the Policy Bureau, Director-Gen
eral of the Land Economy and Construction a
nd Engineering Industry Bureau, Director-General, City Bureau, Director-General of the Water
and Disaster Management Bureau, and Directo
r-General of the Housing Bureau, Concerning t

323

9, 2012
http://www.mlit.go.jp/common/000204849.pdf

3.4.3 Research on technologies for disaster
reduction planning in coastal cities (FY20122014)

to post-disaster emergency correspondence, recovery

In coastal cities and towns where fear for similar

temporarily fail, depending on the intensity and form ofand restoration for the entire city and towns, althoughsome of the facilities may be damaged anddisasters and damages as those of the 2011 off thethe disaster such as tsunami.

Pacific coast of Tohoku Earthquake has grown, there
is an urgent necessity for countermeasures, such as(3) Data preparation for technical standardization offor smooth evacuation of citizens, sustainability ofsoil liquefaction countermeasuresurban disaster preparedness functions and against

To establish the numerical criteria for housing site

housing area liquefaction. These urban disasterdisaster

mitigation measures should be reflected in theperformances are established, and for corresponding

disaster mitigation structuring plan of the cities andspecific target levels (such as index of allowable

towns.

amount of land subsidence), the basic data is

reduction,thetargetedrequired

For this reason, the following research is being

collected and arranged. Also the basic data isconducted under a three-year plan since FY2012, withanalyzed and arranged for setting the specificationa mission to develop a planning method and technicalstandards for each ground characteristics anddata required for Japan’s technical guidelines andconstruction method.

technical

standards

onpromotion

mitigation

structuring,

includingof

disastercountermeasuresagainst tsunami and widespread land liquefaction incoastal cities and towns facing risk of massive
earthquakes in the future.
(1) Urban development planning method based on
evacuation safety
A multi-agent tsunami evacuation simulator isdeveloped, to predict the evacuation behavior ofresidents in various disaster scenarios.
In addition, this simulator can be used in identifying
districts which would have many people who have

Figure 3.4.3.1 Image of disaster mitigation structuring

trouble evacuating and districts with insufficientof coastal city

evacuation areas, and extracting important evacuationroutes, to establish a method of drafting the urban
development plan for improving the evacuation safetyof residents.
(2) Planning method to secure redundancy of urban
disaster preparedness functions
For disaster preparedness facilities such as local
government offices, shelters, medical and emergency
facilities, firefighting and rescue facilities, methods ofplanning
facilities,

theirlocations,linkingdesignating

facilities,

andsubstitute
flooding

countermeasures are studied. The aim is to ensure
their essential functions in the required phases leading324

3.4.4 Research on Risk and Crisis Management

viewpoint based on the concept of “damage reduction”:

Strategy for Excessive and Multiple Actions of
Natural Disasters (FY2012-2014)

full mobilization of structural and non-structural measures,construction of resilient land and infrastructure which

The Great East Japan Earthquake struck on March 11,

enhances response capacity to large scale disasters,

2011. It caused a huge tsunami far beyond previous

and resilient multi layered defenses.

estimations, along with strong shaking over a wide area

In the light of such lessons learned, with giving thefrom the Tohoku region to the Kanto region. The disasterhighest priority to protection of the residents’ lives, there

devastated a wide area. Subsequent Typhoons No.12

is a need to build resilient land and infrastructure which

and No. 15 also caused floods and sediment-related

can maintain the minimum required social and economic

destruction while the area was still reeling under thefunctions, considering disaster risks which were notquake damages. Important lessons learned from theseassumed previously.

disasters are shown in two points below.

Against this background, research project “Research

It is essential to:

on risk and crisis management strategy for excessive● prepare for natural disasters of sizes previously not

and multiple actions of natural disasters” over the threeexperienced nor forecast

years from FY2012 to 2014 was started by the National● prepare for multiple disasters, such as combinations ofInstitute of Land and Infrastructure Management with theearthquakes, tsunamis, floods and landslides.

purpose to build “damage reduction” techniques bymobilizing all possible structuraland non-structural

These kinds of issues were pointed out by the Central

measures. This study aims to clarify the occurrence andDisaster Management Council etc., and the Central

the impact of excessive and multiple natural disasters

Disaster Management

Council’s “Committee forwhich were not sufficiently considered previously, andTechnical

onpropose techniques to build crisis management

Investigation

CountermeasuresforEarthquakes and Tsunamis Based on the Lessons

measures against such unforeseen disasters.

Learned from the 2001 off the Pacific coast of Tohoku

As shown in Fig. 3.4.4.1, there are various disasters:

1

Earthquake” recommended the following.

earthquakes, tsunamis, floods, volcanic eruptions, storm(1) The largest possible mega earthquakes andsurges, and sediment related disasters such as

tsunamis should be considered from every possible
angle.(2)landslides.

One should be aware of thePreviously,

countermeasurelevelswere

setpossibility of actual damage exceeding the damage

considering that these respective disasters occur

expected and of the uncertainties of estimations

independently, but this research covers the possibilities(3) Full preparations need to be mademega

aof actions of excessive force over those levels, andocean trench earthquake in the Nankai

multiple disasters considering mutual interaction among -trough andTokyoagainstInland Earthquakes

several disasters.

shouldFor example, multiple disasters could be landslides

also be reviewed and considered(4) It is necessary to consider such cases: Tokai,

and flood disasters due to floods after an earthquake or

Tonankai, and Nankai earthquakes occur at thedue to heavy rain after volcanic eruptions. For thissame/subsequent time: Multiple disasters such as

purpose, three broad research points have been set as

earthquake and typhoon.

shown in Fig. 3.4.4.2.
In other words, the aims are to 1) know, 2) have an
insight into and 3) manage the phenomena and impactsof excessive and multiple natural disasters.

In addition, based on the recommendations of theCentral Disaster Management Council, “Basic guidelines

Firstly, in 1) “know,” examples of disasters which

for reconstruction in response to the Great East Japanactually occurred in the past are collected, and what2

also indicated a broad policy to create

happened in these disasters is reanalyzed. This stage

regions which are strong against disasters, from awill include historical and overseas disasters, and study

Earthquake”

325actual damages to see how damages occurred during

preparing against excessive force over previous

the disasters, how they progressed, and how each

expectations,individual event in a disaster spread and made an impact

framework for combining structural and non-structural

on society.

measures, techniques required to boost the evacuations

limitationofstructural

measures,In “2) insight,” based on the analysis of the actual

to save lives and the non-structural measures, applicabledisasters, the study will look at what happens due totechnologies for early recovery and maintaining theexcessive and multiple disasters, and study techniques

functions of facilities.

to develop disaster scenarios without overlooking

As a result, starting with the recovery andimportant impacts, and methods to evaluate risk levels

reconstruction measures for the Great East Japanand impacts. The disaster scenarios shall be studied

Earthquake, and study of three linked earthquakes inconsidering vulnerabilities due to characteristics of the

Nankai Trough, the research shall proceed quickly so it

region, such as urban and mountain areas.

can be used in mitigation measures which also consider

future large scale disasters.

Lastly, in “3) manage,” methods for preparing disasterprevention facilities and crisis management measures forexcessive and multiple disasters shall be studied. A

References

menu of countermeasures including structural and1) Central Disaster Management Council “Committee

non-structural measures shall be studied, these shall be

for Technical Investigation on Countermeasures forapplied to a model region to check what kinds ofEarthquakes and Tsunamis Based on the Lessons

countermeasurestheLearned from the Great East Japan Earthquake”:

effectiveness of the countermeasures shall quantitatively

Report of Committee for Technical Investigation on

evaluated. Many combinations of multiple disasters are

Countermeasures for Earthquakes and Tsunamis

possible, but this research will first focus on combinations

Based on the Lessons Learned from the Great East

would

be

effective,

andwith floods.

Japan Earthquake, September 28, 2011

This study started in FY2012. Its research results shallwww.bousai.go.jp/jishin/chubou/higashinihon/index_

be summarized as a collection of cases including the
scenariodevelopment

techniques

andhigashi.htmla2) Reconstruction Headquarters in response to thecountermeasures menu. The results will be issued in a

Great East Japan Earthquake: Basic Guidelines forformat ready to use as a reference while studying

Reconstruction

disaster preparedness and countermeasures.

Earthquake, July 29, 2011

Discussions are to be carried out to gather various

from

the

Great

East

Japan

http://www.reconstruction.go.jp/topics/doc/20110729

options and ideas, such as the approach towards

houshin.pdf

326

Figure 3.4.4.1 Excessive force and multiple natural disasters

Figure 3.4.4.2 Research on crisis management for excessive and multiple natural disasters327

3.4.5 Research and Development
Information and Technology Areainthe establishment of a novel “human mobility
information” survey system is highly desired, which

3.4.5.1 Research on the platform development forprovides a flexible and agile means conducive tocollecting and analyzing movement of people

grasp the immediate aftermath of the disaster.

(FY2012-2014)

Thanks to the progresses in ICT (e.g. GPS mobile(1) Overview

phones, car navigation systems, and traffic smart

The Great East Japan Earthquake caused

card for railways and buses), a huge amount ofcatastrophic disruptions and interruptions in public

extensivetransportations – railways, busses and others –information regarding movement of people has

resulting in more than 100,000 travelers (e.g.

become available 24 hours a day throughout thecommuters, students, etc.) having difficulty returning

year. Naturally, suggestions have been made tohome. The experience made us open our eyes toutilize it as the source of movement of people.

andup-to-the-moment

digitalized

the importance of having a grasp of “movement ofpeople”, e.g. the number of stranded travelers, the(3) Combination analysis of movement of people:

status of movement of people after the earthquake,

expectations and challenges

and1) Past researches

where

they

are

accumulated.

The“Recommendation on the Reconstruction Planning”

The rapid growth of big data analysis and related

drafted in the wake of the Great East Japantechnologies in recent years has produced an

Earthquake stressed the need for pointing to newincreasing

directions for the construction of a disaster-resilient

movement of people (typically in areas such ascountry in the future, where the infrastructure has

marketing,the pliancy and robustness to endure disasters anddistribution and economic loss caused by a traffictohold-up). For example, the information obtained

maintainthecapacities

foruninterrupted

economic and other activities.

numberandofapplications

calculations

toof

exploitpopulationfrom the smart card data for bus travelers enabledThis section presents an outline of the measurestrend visualization in the number of bus users in theset toward the construction of an ICT (Information &regions

Communication Technologies)-assisted information

Earthquake.

gathering/analysis platform (see Fig.3.4.5.1). The

movement of people in a single mode – i.e.

plan was launched in 2012 to provide accurate andincoming and outgoing number of bus users – andup-to-the-moment

does not give information regarding the behavior of

information

regardingtheaffected

by

the

Great

East

Japan

However,it

only

providesthe

movement of people.

people using plural transport means.

(2) Current status of movement of people gathering

Management has already worked on some of the“Movement of people” as stated in this section

issues in preparation for use in effective trafficmeans the history recorded of the movement

planning (e.g. “A supporting method for bus

passages of people: who moved, the point oftransportation

The National Institute for Land and Infrastructure

planning

andeffect

of

road

2)

departure and destination, and the purpose andimprovement by using multiple trail data” ), in whichmeans of the travel. Up to the present, several

an effort was made to combine smart card data formodes of statistical survey – such as a person trip

bus travelers and probe car data from private

survey (hereafter referred to as PT survey) and roadenterprises. These studies have revealed many

traffic census – have been implemented for graspingfavorable effects and knowledge obtained byhuman mobility information, which represent only

analyzing sources of movement of people inone-day data and are conducted only sparsely, on a

combination. In addition to possible achievements

once-in-5/10-years basis. In addition, these surveys(expectations) gained from the combination analysis

require a large budget. Under such state of affairs,

as described in the next section, the study

328

summarized the challenges to be overcome for

implementing the measures.
To enable
coupled analysis byexpressing
standardized forms

Current
IC card

Node

Node

Node

Node
IC cardProbe

IC cardNode

IC card

Node

Probe

携帯電話
Mobilephone

Probe vehicle

Human migration
information platform
Expansionof utilization
opportunity

Mobile phone

Node

携帯電話
Mobilephone

Node

Node Weather

Railway and IC card

Figure 3.4.5.1 Schematic Representation of Movement of people Platform
2) Expectations for Combination Analysis

evacuation routes.

Analysis of various types of movement of people
3) The Challenge of Combination Analysis

in combination enables grasping, or visualizing, thetraffic behaviors (human mobility) individually in a

Although

it

seems

highlylikelythatthenear real-time fashion. An example of a combination

combination analysis of a variety of movement ofanalysis is the estimation of the number of travelers

people provides a much higher level of efficiency,

who had difficulties returning home due to thevirtually no mechanism is in place to promotedisaster3), which made use of mobile phone datacollaborative interaction among these sources,and PT survey data (see Fig.3.4.5.3). The mobile

which are separately collected and managed byphone data provided “quantitative” aspects of theeach organization/agency/enterprise independently.

situation – understanding how the human flow was

One possible cause of the situation may be ascribedjammed and where people were stranded on ato the blurred boundary between collaboration andday-to-day and time-to-time basis. The PT survey

competition in the field that is still in a growth stage,

data provided information regarding “qualitative”

and the private sector market is very much in its

aspects of the situation – the purposes of travels

infancy. As each private enterprise has its own

and the means of transportation used. The

marketing strategy, getting along under present

approach proved effective to estimate the situation –circumstances,classification of the stranded population based oncollaborative use, will make the analysis through

their

of

combined use of information sources – fromtransportation used on a region-to-region basis –organizations and enterprises on the mode ofpromising its applicability in disaster prevention field,

transportation basis - even more difficult.

travelobjectives,

and

the

means

i.e. support for returning home and planning of329

withoutamechanism

forThe day before the earthquake, on Thursday,
March 10, 2011

Immediately after the earthquake, on Monday,
March 14, 2011

Immediately after
the earthquake,
reducing bus users-10 passengers per stop per day
11-20 passengers per stop per day
21-50 passengers per stop per day
51-100 passengers per stop per day
101- passengers per stop per day

Figure 3.4.5.2 Distribution of Bus Travelers: Before and After the Great East Japan Earthquake

Mobile phone
Grasp of mobile population
910 thousand
persons

15 thousand
persons

56 thousand
persons
940 thousand
persons

With a combination of two data, to realize graspingcongestion and transfer populations by purpose, congestion
population of the elderly by time period, and the elderly’s
outing rate and transfer means by region

Quantitative grasp by mobile phone data

770 thousand
persons

The above indicate temporary figures

Person Trip (PT) survey◆Quantitatively-sufficient datacollection for 24 hours a day, everyday・Enable grasping the humancongestion and transport situation by
day and time period
・Enable grasping by attribution (age,gender)Examination of actual situation for the number of travelers who find difficulties
returning home and home-coming support

Enable use for the examination on home-coming support though
grasping the actual situation of travelers who find difficulties returninghome by area

*Transfer purposes and usedtransportation mean are unknown

Qualitative grasp by PT survey

Grasp of transfer purposes◆Collect qualitative data in PT
survey・Situations by transfer purpose andused transportation means
・Enable grasping family composition,etc. by attribution (age, gender)

Twelve o’clock

kilometers*Sampling rate of PT survey is about 2%
in Tokyo PT(person/ha)

Source: “2006 Report: Survey on metropolitan/urban planning addressing the challenge of travelers who find difficulties
returning home (estimate of affected population)”, City and Regional Development Bureau, Urban Development andImprovement Division of MLIT, March 2007

Source: “2006 Report: Survey on metropolitan/urban planning addressing the challenge of travelers who find difficulties
returning home (estimate of affected population)”, City and Regional Development Bureau, Urban Development andImprovement Division of MLIT, March 2007

Figure 3.4.5.3 Graphical Representation of the Estimated Number of Travelers That Had Difficulties
Returning Home in the Wake of the Disaster (Based on the Combination Analysis of Mobile Phone Data andPT Survey Data)(4) Efforts toward Establishing Movement of people

to continue for three years, with the following

Platform

implementation schedule for each year:

In light of the challenges and current status

FY2012: Discussion and consultation with thosedescribed in the preceding sections, this researchorganizations/agencies that own types of movement

aims at constructing an information infrastructureof people for the availability of the data and(platform)

analyzing

establishing

up-to-the-moment movement of people available

exploitation,from ICT applications. The research project is slated

implementation of a demonstration experiment inforcollecting

and

330

commonincludingspecifications
the

for

betterplanning

forthe next year.
FY2013:challenge of collecting and analyzing movement of

Implementation

experiment,

in

of

a

collaboration

demonstration
withpeople.

eachorganization/agency, for collecting and analyzing theReferences

movement of people in some model areas. The

1) TheReconstruction

DesignCouncilinresults will be evaluated for their usefulness andResponse to the Great East Japan Earthquake:applicability.

“Recommendation

FY2014: The development of a platform prototype.

Planning," 2011

on

the

Reconstruction

Institutional design, including terms of use, will be2) Shunichi HAMADA, Ryuichi IMAI, Yuki IBOSHI,

developed assuming that the system will be placed“A supporting method for bus transportationin actual operation starting in 2015.

planning and effect of road improvement by

These efforts are expected to help complement theusing multiple trail data,” Civil Engineeringresults of current statistics surveys, and will enable,

Technical

Document,

Vol.53,

No.10,

2011

in the future, administrative services to respond(pp.22-25), Public Works Research Center

more quickly and adaptively in real-time in the time3) Ministry of Land, Infrastructure, Transport andof a disaster. They also contribute to establishing

Tourism (City Bureau, Urban Development anddisaster prevention plans that address more closely

Improvement Division): “2006 Report: Survey

to the characteristics of population groups (age,on metropolitan/urban planning addressing thedisabilities, etc.).

challenge of the travelers who find difficulties

We forge ahead with the above-described studies

returning

continuously aiming at practical implementation of

population),” 2007

home

(estimateofaffected

the infrastructure (platform) that addresses theRealize a platform to collect andanalyze human mitigation
information individually acquired ina standardized form

Probe vehicle

Difficult to travel home

Human mitigation
information
platform (PF)Mobile phone

Railway and bus IC card

Various people’s
trip information
on disasters

Congestion of persons

Suspension of public
transportation services

Traffic congestion

In case of fire
Human mitigation
information platform

Grasp of number of travelers who finddifficulties returning home, transfer
situation and congestion places

Alternative transportation/Traffic control

Grasp and analysis of trips of
persons and goods during thepast disasters

Supply of rest and accommodating facilities

Home-coming support (Sites for
distributing boiled rice, etc.)

Prompt information supply

Figure 3.4.5.4 Graph depicting active use of the movement of people platform in the time of a disaster331

3.4.5.2 Research on supportive use of 3D
CAD data for disaster rehabilitation
processes (FY2008 – FY2014)

Input

Imaging process for trihedral figures

LP

Designated range removal processing

Output(1) Overview

Noise reduction LP

Early establishment of efficient terrain information
Input

gathering technologies and their application for

Noise-free function of LP

Break line extraction processing
Extracted range’s limited processing
Section change point acquisition processing

rehabilitation planning have become an urgent
research objective in the wake of the Great East
Japan Earthquake. The relevant research areas

OutputBreak line creation processing

Break line data

3D CAD data creating function
Input

include: grasp of the damage situation of facilities
dispersed in a wide area, selection of candidate

Filter creation processing
point cloud data interpolation processing

3D CAD data creation processing

sites for provisional housing and determination of
the soil volume required for their construction. To

Input

CAD data of thecurrent terrain profile

address these challenges, this research focuses on
the development of technology that enables the

3D CAD data correcting function by
the current terrain profile
Section acquisition processing
Section correction processing

automatic creation of 3D CAD data from existing

Section-corrected 3D CAD data

sources of data – typically from a laser profiler(hereafter referred to as LP). In addition to disasterFigure 3.4.5.5 Steps to create 3D CAD dataapplications (e.g. rapid grasp of existing state ofaffairs and determination of soil volume andFigure 3.4.5.5 shows 3D CAD data generationmaterials required for restoration works), theprocedures using the novel technique. The first stepresearch also aims at establishing a method of 3D

is to remove outliers (noises) from the LP point

CAD data utilization at normal times, for example,

cloud data – e.g. vegetation, etc. Then, break lines

computerized

are extracted from noise-free LP data. The novel

construction

andstreammanagement.

technique automatically extracts signature points

This report describes, as the first in the series, thecharacteristic of the profile from LP data using theseresults from practicality verification for 3D CAD data

as a clue, and determine the break lines (seegeneration from LP data and a comparative case

Fig.3.4.5.6). Finally, LP data and the break lines are

study pre- and post-disaster analysis of Kitakami

combined to generate TIN (Triangulated IrregularRiver’s downstream basin using 3D CAD data.

Network), resulting in the creation of 3D CAD datathat trace the current terrain profile. The technique(2) 3D CAD data generation technique using LP

also support editing the 3D CAD data using

This section reviews the technique to generate 3D

information gained from measured lateral profiles. In

CAD data using LP data. The technique features thecomparison with conventional techniques, the one

ability to automatically generate 3D CAD data forreported here provides 3D CAD data capable ofaccurate trace of terrain profiles “as is” using the

tracing current terrain profiles much more accurately

point cloud data provided by LP, by extracting(see Fig.3.4.5.7). Note that this report does notborder lines (or, break lines) where a river bank’s

intend to cover all aspects of the technique: seelevee crowns and slopes meet and terrain altitudereferences 1) - 3) for the details of individual functions.

changes.
Border between
surfaces

Break line
Designate the range to extract
break lines from LP data

332

Determine the border
between surfaces fromeach extraction range

Extract a break line to bindthe border between surfaces

Fig.3.4.5.6 Break line extraction procedures

areas. In addition, existing sets of documents,
including the flooding area map, were examined as
along

with

the

knowledge

gainedthroughperforming on-site explorations. Based on thesepreliminary considerations, the target of this study

The border between
crown and berm

was defined as the area, stretching over 1,800m,
shown in Fig.3.4.5.8. Note that the flooded area
map, provided by the Geospatial Information
Authority of Japan, is overlaid onto the figure.
・ A flooded area in the downstream of KitakamiRiver・ A location severely affected by the disastera) Creation of 3D CAD data by conventional methods

・ A location that require urgent rehabilitation
because of a heavily deformed dike
The 3D CAD data was generated from two

The border between
crown and berm isclearly expressed

sourcesofinformation:

pre-disasterLPmeasurements combined with the aerial LiDAR data
conducted for river improvement evaluation, andpost-disaster LP measurements combined with theaerial LiDAR conducted by the Geological Survey
Institute in the wake of the Great East Japan
Earthquake.

b) Creation of 3D CAD data by new technology
Aspects of the field survey

Figure 3.4.5.7 Comparison of 3D CAD data: newand old method(3) Analysis using the pre- and post-disaster 3D
CAD data: a case study
This section describes the results of a case study,[Target area of a case study]
Range of 1,800m around Kitakami Bridgein which pre- and post-disaster terrain profiles traced based on the 3D CAD data rendered from LP
data using the new technique - were used to

Figure 3.4.5.8 Target area of the case study

evaluate the level of damage caused by the disaster(e.g. extraction of heavily damaged locations). The

2) Comparison between pre- and post-disaster 3D

objective of the study was to evaluate the

CAD data

effectiveness of this technique for grasping the

In this analysis, two sets of 3D CAD data – one forsituations in the affected areas rapidly andpre-disaster and one for post-disaster terrain – areaccurately immediately after the disaster, andsuperimposed for visualization, and are examined if

whether it is capable of providing useful information

the locations with possible damages or with large

for disaster rehabilitation.

geological changes can be identified through visualinspection. Fig.3.4.5.9 shows two aerial views

1) Target area and LP used(before and after the disaster) and a superimposed

To reflect the post-disaster situations, the three

representation of pre- and post-disaster 3D CAD

criteria listed below were set for selecting target

data. The dike shape in two areas in the figure,333labeled A and B, shows significant changes before
Further examination aroundand after the disaster.

the dike reveals that the dry riverbed near the dike,labeled B in the figure, is inundated. Pre- andpost-disaster surface geometry in the area C showchanges due to piled rubble. The above-described
observations clearly indicate the effectiveness of thetechnique, i.e. superimposed drawing of pre- andpost-disaster 3D CAD data and aerial views enables
easy identification of locations that may haveThreshold=1m

Threshold=2m

Threshold=3m

Threshold=4m

suffered large changes in terrain profile.

A

A

C

C
D

A

B

Aerial view (Pre-disaster)D

C
B

Aerial view (Post-disaster)
LegendB

D

Sets of 3D CAD data
superimposed

Pre-disasterPost-disaster

Abnormality
determination

LegendFigure 3.4.5.9 Sets of 3D CAD data superimposed

Normality
determination

Figure 3.4.5.10 Damaged locations along the riverbank3) Comparison of arbitrary shape cross-section:
before and after the disasterAs the river dike under review in this research has

Although no mention was made in the previous

a typical convex shape with the tops of slope on

section (2), the new technique additionally features

both sides of the levee crown, two break lines werecomparison of pre- and post-disaster break lines,

used to detect potentially damaged locations.

enabling determination of affected locations from

In-depth examination of these locations revealed

the level of displacement among break lines (i.e.

that a certain deformation length (4m in this case)detection of candidate locations for further analysis)

provides a good threshold to distinguish large and4). Fig.3.4.5.10 shows the damaged locations

small damages. The area enclosed by a rectangle indetected by this function.

Fig.3.4.5.10 shows the severely damaged area,

In this analysis, an attempt was made to compare

where urgent rehabilitation work was done under thethe break lines before and after the disaster for theirinitiative of the river administrator 5). To verify if thedegree of displacement from small to large, which

damagedwas considered to represent the severity of thecross-sectional

damage.

undamaged locations shown in Fig.3.4.5.11 werelocationswere

profilesproperlyofdetected,damagedandgenerated: the cross-sections B, C, D (severely
damaged) and cross-section A (unaffected) are
shown in Fig.3.4.5.12. Aerial views of two of theselocations, before and after the disaster, respectively,
are also shown in Fig.3.4.5.13. Examination ofthese figures indicates:
・ The lateral profile of location A is substantially

334

6

dike around it maintained its levee crown shape5

Altitude (m)identical before and after the disaster, and thealmost unaffected. The aerial view around thislocation (upper two in Fig.3.4.5.13) also suggests

4
3
2

preservation of the road and dike structure,1

despite the pile of rubble. These observations

0

clearly indicate that the method is capable ofidentifying

unaffectedorslightly0

affected

15

30

45

River levee width (m)locations.

Section A (Normality determination)

・ The cross-sections B and C indicated changes incrown

shapes,andespecially6

thedeformation of the top of slope, facing inward
toward the dike, was substantial. This indicates
that

the

methodcorrectly

detected

5

Altitude (m)

levee

4
3
2

local

1

damages.

0・ The shape of lateral profile D showed significant

- 10

5

20

change before and after the disaster, as alsoRiver levee width (m)evidenced by the pre- and post-disaster aerial

Section B (5m section of threshold)35

6around the location D (Fig.3.4.5.13) reveals

5

Altitude (m)views around it. A close look into the aerial viewlarge-scale deformation in the dike geometry.
Actually, the area around the location D was

4
3
2

found to have concentrated damages to where1

urgent rehabilitation works were implemented.

0This indicates that the method is capable of- 10

detecting the locations where the dike geometry

5

20

35

River levee width (m)underwent substantial localized deformation.

Section C (4m section of threshold)6
Altitude (m)Section D (6m of threshold)
Section A (Normality determination)

5
4
3
2

Section C (4m of threshold)10-5Section B (5m of threshold)

10

25

40

River levee width (m)Section D (6m section of threshold)LegendNormality
determination

Abnormality
determination

LegendPre-disaster
section line

Post-disaster
section line

Figure 3.4.5.11 Damaged locations where lateral

Figure 3.4.5.12 Four lateral profiles indicating varied

profiles were madedegrees of damage
3) Differences in soil volume inside the dike: before
and after the disasterIn this analysis, an attempt was made to verity if
the method is capable of estimating the soil volume335

required for rehabilitation work. For this purpose,

data currently in use in river projects (e.g. survey

two sets of 3D CAD data – before and after thedata). The following sets of knowledge weredisaster - were generated by using the 3D CAD dataobtained through a case study that used pre- andgeneration function, and the data were analyzed

post-disaster 3D CAD data, confirming versatility ofalong the river level to determine the difference inthe technique in a broad range of restoration works.

soil volume inside the dike. We used the soil volume

・ The long shot view gained through this techniquecalculation function of AutoCAD Civil 3D in thismakes the grasp of terrain situations easier -research, and it worked out the required values

surface deformation of dikes, spotting severely

without major difficulties.

damaged locations, etc.

The results indicated that the rough amount of soil

・ 3D CAD data allows easy generation of lateralrequired to restore the pre-disaster dike can well be

profiles at an arbitrarily selected location,

worked out, even in the wake of a large-scale

enabling

disaster that may have accompanying crustal

including the changes of dike geometry, varied

variations, suggesting possible use of these results

rate of ground subsidence, etc. These sets ofas the basis for estimating the scale and cost of theknowledge contribute to rapid rehabilitation

rehabilitation works. Note that the calculated results

planning and setting up of construction work

were not compared with the soil volume actually

management.

examinationofimportant

items

used in restoration works, disabling accurate

・ The new method makes quantitative estimates of

estimation of the calculated soil volume. Therefore,damage situations easier (e.g. soil volume

the calculation results are not presented in thiswashed away by tsunami), enabling early grasp

report.

of the scale of restoration works (quantity
survey).

D section line

Subsequent research, from FY2012 to FY2014,

D section line

focuses on an automatic generation method of 3D
CAD data using existing LP data, whereby theachievement presented here provides the starting
point. It also aims at expanding the scope of

Figure 3.4.5.13 Aerial views: before and after theapplicability to other structures in addition to riverdisasterdikes.

The

researchwillbeconducted,

incollaboration with regional development bureaus,(4) Summarywith a view toward effective applications of 3D CAD

This research focused on the method to generate

data in information assisted construction and river

3D CAD data from an existing mass of data –management, leading finally to the construction of atypically those from laser profiling (LP) – andplatform for active and flexible use of existingexamined how they can be fully exploited. This

information sources and assets in times of disaster,report, the first in a series, describes practicality

as well as during normal periods.

verification of the new technique (i.e. generation of

The content of this report is based on the

3D CAD data from LP data) and the results obtained

achievements gained through the collaborative

so far from a case study targeted on thestudies conducted by the researchers in the Kinki

downstream basin of Kitakami River – 3D CAD data

Regional Development Bureau (Ministry of Land,

based examination of pre- and post-disaster terrain

Infrastructure, Transport and Tourism), Kansai

features.

University

Practical utility of the new technique was(Prof.

Shigenori

Tanaka),andthe

National Institute for Land and Infrastructure

examined, and the results obtained through thisManagement.

technique proved to have accuracy on a par with the336References
1) Shigenori

Tanaka,RyuichiNakamura,

Kohei

Kawano:

Imai,

Kenji

“Researchon

generation of a 3D model using point cloud
data,” Journal of Applied Computing in Civil
Engineering, Japan Society of Civil Engineering,
Vol.19, pp.165-174, 2010
2) Tanaka, S., Imai, R., Nakamura, K., Kawano, K.:
Research on Generation of a 3D Model Using
Breakline from Point Cloud Data, Proceedings
of

the

10th

International

ConferenceonConstruction Applications of Virtual Reality,
pp.347-356, 20103) Shigenori

Tanaka,RyuichiNakamura,

Kohei

Kawano:

Imai,

Kenji

“Researchonautomated generation of a 3D model using point
cloud data,” SOFT Journal (a publication ofJapan Society for Fuzzy Theory and Intelligence
Informatics), Vol.23, No.4, pp.198-216, 20114) Shigenori

Tanaka,Ryuichi

Imai,

Kenji

Nakamura, Kohei Kawano: “Visualization of theAutomatic Detection Results of the Affected
Areas Before and After the Earthquake DisasterUsing LP data,” Journal of Japan Society of Civil
Engineering F3 (Civil Engineering Informatics),
to be published as of December 28, 2012.
5) Ministry of Land, Infrastructure and Transport,
Tohoku Regional Bureau: “Damages caused by
the Great East Japan Earthquake: Naruse andKitakami river”
http://www.thr.mlit.go.jp/karyuu/taiheiyouokijisinn/index.html, (available since 2012.12.28)

337

3.4.5.3 Research on the management method of

position, (2) on-site display of deviation from designburied debris using computer aided construction

values, and (3) automatic report generation using

technology (FY2011-FY2012)

measured data.

(1) Objectives and history of the research

NILIM has already worked out the proposed plan

Disposal of the enormous pile of debris in the“the data exchange standard for TS-assisted

wake the Great East Japan Earthquake (March 11,

as-built measurement” (hereafter referred to as the2011) poses urgent and serious issues in the“dataaffected areas.

specifications of “construction control data”, i.e. 3D

exchangestandard”),

which

defines

The approaches now under review include

design data and measurement data. The data

reclamation of debris for use as construction

exchange standard has been updated to Ver.4.0 inmaterials for such purposes as embankment. This

September 2011. In contrast to Ver.2.0, whichapproach,management

contains only the data items directly related tomechanism that ensures seamless monitoringearthworks, the revised version has the capacity tothroughout

however,therequiresprocess–acollecting

contain such additional information as: data relating

information on the nature of the debris to long-termfromto pavement and underground installation, date andmaintenance strategy after burial in the groundtime of measurement, and nominal designation ofdebris may contain substances different fromthe work.

conventional soil and is rendered invisible after theThis research focuses on the method to facilitate

filling work has completed. The National Institute formanagement of underground burial of debris andLand and Infrastructure Management (NILIM) has

other materials, where the as-built measurement

been

technologies

conducting

researchesonas-built

using

TS

(especiallythosemeasurement techniques using computer aided

implemented with the new data exchange standard,

construction technology, typically TS (Total Station:

Ver.4) are brought into full use.

a

3D

surveying

instrument)

that

is

finding

increasingly wide applications in earthworks. This

(2) Concept of buried object management using

technology, with 3D design data (3D shape

TS-assisted as-built measurement technology

information on completion) implemented in TS

In management of buried objects, the capacity tosoftware, improves the efficiency of construction

grasp positional information is highly desirable

procedures: (1) easy navigation to a measurement

because they are invisible from outside after

Figure.3.4.5.14 Work flow of burial object management338

completion of the work. Their positions are usually

Therefore, additional functions were implemented

determined by examining the drawings prepared at

to register these data in a CSV file. For easy

the time of burial work, but it often involves anoperation for anyone to use the function, an input

additional task of writing in new information to thesheet (Excel macro) is provided to help create thefinished drawings. In addition, as conventional

CSV file. The function also provides room forpractice entails storage of information on aaddition/modification of input item definitions towork-by-work basis, sets of separate documents

accommodate

are generated even for the burial works done next

requirements – debris often defy standardized set

to each other if they are implemented separately,of data items for management because of its

necessitating

unpredictable nature and shape.

cross-referenceofmultipleitselftothemanagement②Data search function

documents for later use. As-built measurement is arequirement in every civil engineering work, andThis function allows the manager to retrieve

application of TS on as-built measurement ofnecessary information to make full use of the data.

underground burial works is considered conducive

It must provide a variety of searching functions

to gain accurate positional information (i.e. highusing such keys as: by name, by manager, as well

precision 3D coordinates) of buried objects. Higher

as by pointing to a location on the map.

efficiency is in sight if the information useful for

The map search function allows, by pointing to a

post-construction operation and maintenance islocation on a map, creating the list of all objects

addedburied on that spot, and selecting an object in the

to

the

data

set,

enabling

unifiedmanagement of the buried objects.

list will display all the detailed information registeredfor it. The construction control data allow 3D(3)Requirements

reviewofburialobjectgraphic display as well as data output, and the data

management softwareis portable for writing in an on-site TS, enabling

Based on the conceptual description in (1), aeasy navigation to the spot where the object isreview was made on the functional requirements ofburied.

burial object management software that uses
construction control data. Required functions for(4) Summary

this software are:As described above, application of TS-assisted①Data registration function

as-built measurement on underground burial works

This function allows registration of information

is expected to streamline the procedures in burial

required for the management of burial objects.

object management. Continuous research efforts –In the case of government's works, the data isdelivered

as

set

of

through

trial

and

error

in

automatically extracts the relevant files from the CDtechnology into active use. In parallel with this,andProperproactive field use of TS in as-built measurement ismanagement of buried objects requires, in addition

highly desirable, especially on the burial objects

to their locations, a set of auxiliary information suchthat may require continuous management into theas the work designation and the person in charge.

future: the data thus gathered will constitute a

However, the construction control data contains

valuable

only the information directly related to construction

maintenance.

the

The

learning

laboratories - will be needed to bring thisthem withCDs.

typically

softwareregisterasystem.

works (e.g. shape, measurement time, etc.).

339

asset

for

futureoperation

andFigure.3.4.5.15 Flow of operation: Burial object management software340

3.4.5.4 Research on Bridge Monitoring Technology
using 3D CAD Design Data (FY2009 –FY2013)(1) Research objectives
CALS/EC is a system aiming at establishing aseamless chain of data, through which each phase–from survey, design, construction to operation andmaintenance – inherits necessary information from the
upstream phases. The data distribution mechanism
currently in place – from design to construction,
operation and maintenance - is based on theexchange mechanism of 2D CAD drawing data. 2D
CAD data, however, presents three-dimensional
structures using a set of plane, longitudinal and lateraldrawings, and is not capable of directly handling 3D
data required for efficient construction, operation, andmaintenance purposes. To address the current state ofaffairs, researches are under way to promote the flow
and common use of 3D data, especially in the area ofbridge design where 3D design and construction have

SerialMarkNumber

Monitoringreference point

already shown a certain level of progress. As part of●●●these efforts, we carried out a study to promoteDate
for installation
Implemented
Dateeffective use and distribution of 3D data in the time of
MLIT on mm/dd/20yy

disaster.
A disaster such as an earthquake or landslide cangive rise to displacement and torsion of the base andFigure 3.4.5.16 Implementing a Monitoring Reference

upside of a bridge. These abnormal events, however,Point

may remain unnoticed unless apparent damages are(Upper: Monitoring Reference Point placement,

visible, though they can exert detrimental effects on
the

basis

and

superstructures.

Lower: Survey rivet)

Therefore,

displacement and translation must be determined after(2) Monitoring reference point

the occurrence of a disaster.
Certainty cannot be ascertained with regard to the

The experts in bridge construction have pointed out

displacement and torsion of a bridge if the initial

the importance of defining reference points (3Dpositions are unclear. Therefore, we propose tocoordinate

measure and monitor 3D coordinate values of initialmonitoring and consistent migration of information

positions at the time of completion of a bridge. Our

fromresearch is in progress toward establishing practicaloperation/maintenance stage. In this report, we calltechnology to implement these procedures. An

such reference point a monitoring reference point.

thevalues)forcontinuous

construction

stage

displacement
totheattempt was made to verify the technology by applying

A monitoring reference point represents a set ofit to the post-disaster situation in the wake of the Great

positional coordinates that should be handed overEast Japan Earthquake. The following section

throughout the life of the structure – from construction

describes the interim findings from it.

to operation and maintenance. A set of monitoringreference points is defined in strategic spots in thebridge structure to enable early grasping of damage it
suffered from a disaster.

341

documents for long periods.
(3) Implementing a monitoring reference point

1) Use of a skeleton model

Metallic rivets are implemented at visible strategic

The skeleton model is a wireframe 3D modeling ofpoints – selected from the viewpoint of easy

structural reference points (handed over from themeasurement

anddesign stage to construction work) and installation

contortion. Determination of these positions requiresofdisplacement,

inclination,reference points (handed over from the construction

careful consideration on a site-by-site basis: lower

state to operation and maintenance) connected

positions may be hidden by plant exuberance with

together. A skeleton model features 3D visualization,

time, and higher positions may require a scaffold forenabling display of the level of displacement at MRPs

precision measurement.

visually.

(4) Survey method
The survey for implementing observation reference
points should be based on the data gained through theuse of high-precision, reflecting prism Total Station.
However, the survey in the immediate aftermath of adisaster may involve danger to the operators: setting
up a prism at the monitoring reference point without anadequate scaffold may require work in high places (atthe top of the bridge). Evaluation of structural damage
in the wake of a disaster, if the level of structural
displacement is around 10mm or less, can well bedone with the non-prism TS (survey precision
approximately±5mm)

without

causing

seriouscompromises. From these considerations, a non-prism
TS should be the basic tool for surveys conducted

Figure 3.4.5.17 Skeleton modeling of MRP

after disaster.
2) Use of 3D outline model(5) Generation and distribution of data at a monitoring

Using 3D CAD effectively for the design of thereference point

outside shape of a bridge will be beneficial in many

As a method to secure shared use of information,

aspects: easy understanding of complex structures

we propose to add the survey data of finished work –through visualization, prevention of design errors, easy

typically the monitoring reference points– to the bridge

selection of construction steps and procedures, andcoordinate maps. The proposal represents a delivery

reduction of failures and moving back and forthmethod of job completion documents electronically,

through the steps. Consistent use of the external

and relates to preparing a drawing that includes

shape model produced in the design stage, withpositional reference points (3D coordinate values) of

explicit representation of structural and monitoring

the structures, which were handed over from thereference points embedded in it, will enable visuallydesign stage to construction works. Additional writing

understandable data management.

of the surveyed monitoring reference points into thedrawings constitutes an essential step of this process.

(6) Application case study in the wake of the Great

This scheme brings certain advantages. For example,

East Japan Earthquake

the contractor can easily and consistently generate

In 2011, a survey was made again on the MRPs

monitoring reference point data from the drawings,

implemented in the interchange bridge structures ofand store the modified drawings as the job completion

the Metropolitan Inter-city Expressway Heizogawa

342

Bridge (Chiba National Highway Office) to create askeleton model to evaluate its utility for graspingchanges in the entire bridge structure - displacement,
contortion, etc. (The monitoring reference points were
implemented, in 2010, as part of “FY 2010: Auxiliarytask for utility evaluation of 3D data used in bridge
construction works”)
On-site survey and close examination of the data
gained through the past survey revealed the loss of
temporary benchmarks and reference points (used forobserving MRPs), though the monitoring reference
points were confirmed, by visual observation, to be“normal”. Following this, a survey was conducted

Figure 3.4.5.18 Displacement examination using theanew to define reference points and temporary

skeleton model

benchmarks.
The

monitoringreferencepoint

survey(7) Summary

measurements included displacement examination ofThis study focused on the method of implementation

class-3 reference points (used as known reference

and measurement of monitoring reference points, andpoints) caused by the crustal movement induced by

how we can facilitate migration of the data obtained

the Great East Japan Earthquake (2011). The resultsfrom them. On-site examinations were also performed

were used to correct the coordinate values measured

to confirm validity of the method.

this year (post-disaster measurement). The skeleton

The results obtained from these examinations well

(3D) model thus created using the results from thedemonstrated practical utility of the method, and themonitoring reference point survey is shown in theopinions

figure.

Development Bureau who cooperated in these

Based on the survey results on monitoring referencethepersonnel

intheRegional

examinations strongly support the need and validity ofpoints, types of displacement detected in the bridge

monitoring reference points.

are summarized as below:
・ The

from

Following the validity verification of monitoring
displacedreference point implementation, a set of operational

approximately 17cm southward, and sank 5 to 12

guidelines (a plan) was designed based on the

cm in the aftermath of the earthquake-triggeredknowledge gained from the study, and is being placed

crustal changes.

in on-site practice for review. In the next stage, we willbridge,inits

entirety,

was・ Relative displacement between each abutment

clarify the effectiveness and problems of the methodbase and the bridge structure was more or lessthroughnaught, exhibiting no serious wrecks in abutments

development and widespread use in the future.

and bridges and deformation of the bridge as awhole.
・ The skeleton model created from pre- andpost-earthquake

monitoringreferencepoint

measurement has demonstrated its capacity tokeep track of the bridge status.

343

on-sitepractices,

in

view

of

further

4. Lessons learned and Future Tasks Concerning Disaster Countermeasures andRisk Management
In July 2012, just over a year after the Great East

compounded the disaster, as they occurred while theJapan Earthquake, NILIM formulated and published its

damage from the earthquake was still very much in

Research Policy.

evidence. In light of such lessons, the top priority is toIntended to ensure that each and every staff member atbuild the highly resilient national land that can protect the

NILIM shares a common understanding of NILIM's

lives of the people and maintain the minimum-necessary

mission and the direction and perspective of its researchlevel of socioeconomic functions even under naturalactivities, the Research Policy clarifies the technical andhazards on a scale far beyond conventional experience

policy-related topics that should be dealt with and theand assumptions, as well as complex hazards involving a

research objectives of doing so, as well as setting forth

combination of earthquake, tsunami, flooding andthe approach to research that should be adopted in order

landslides. In addition to developing methods ofto achieve the Institute's goals.

constructing disaster scenarios focused on major hazards

In light of our experience of immense damage due todue to excess external force and complex hazards, and

the Great East Japan Earthquake and discussions

methods of analyzing the risks and impact of these, thisconcerning the lessons to be learned from this, the policy

research will propose risk management measures that

includes research issues that should be dealt with swiftly,

combine structural and non-structural measures to

as a priority. Initiatives have already commenced inminimize the consequences of disasters, as well as

relation to the objectives of "achieving a safe andreliable society", "achieving a society in harmony withthe environment", and "establishing comprehensive
methods of supporting land and infrastructure
management" set forth in the policy. From among thetechnical and policy-related topics aimed at achieving
these objectives, the following provides an overview of
the topics related to contingency planning against an
earthquake disaster and risk management, theresearch goals thereof, and the status of research inthese areas at present.

approaches to the development and management of coredisaster prevention infrastructure to ensure that thesemeasures function reliably.
(2) Research on Multiple Defense Systems for Tsunami
Disaster Mitigation (see Chapter 3.4.2)
In response to the Great East Japan Earthquake, theJapan Society of Civil Engineers proposed dividing theexternal forces from tsunami into the tsunami protectionlevel and the tsunami disaster mitigation level. The former
is used to design measures of perfectly protecting bothhuman life and property by such means as coastal dykes,(1) Research on Risk and Crisis Management Strategy

while the latter is for the design of multiple defense

against Excessive and Multiple Natural Hazards (seesystems focusing on protecting human life via structural

Chapter 3.4.4)

measures in combination with non-structural measures

As well as triggering a major tsunami far in excess ofsuch as resilient city planning and evacuation preparation.

conventional assumptions, the Great East Japan

Accordingly, this research project involves (i) summarizing

Earthquake, which occurred on March 11, 2011, resulted

the lessons concerning tsunami countermeasures thatin strong tremors over a wide area ranging from thewere learned from the recent disaster; and (ii)

Tohoku to the Kanto regions, causing extensive,

summarizing methods of setting tsunami external forces

catastrophic damage. Furthermore, subsequent flooding

for the two levels. In addition, it involves (iii) analyzing theand landslides due to storms including Tropical Storm

factors contributing to tsunami damage to coastal dykes,

Talas (Typhoon No.12 in the Japanese classificationconsidering construction methods to strengthen dykes tosystem)a certain degree, so that they will not collapse easily evenandTyphoonRoke(Typhoon

No.15)
344

if tsunami overtopping occurs, and reflecting thewithin the relevant jurisdiction, based on strong motion

outcomes of these studies in repair and reconstruction

records obtained from a network of seismographs, inwork. Furthermore, the research encompasses (iv)order to ensure that this information hiatus in theproviding support for deliberations concerning city

immediate aftermath of an earthquake is as short asplanning aimed at reconstruction and the development ofpossible, and speed up the initial response. It is also

disaster prevention infrastructure that also takes into

aimed at proposing a method for providing informationaccount the possibility of river tsunami runup; this support

tailored to the circumstances in which the results oftakes the form of compiling a guide featuring standard

damage estimates will be used, such as the consideration

methods of simulating inundation resulting from bothof extensive support measures by the Disaster Response

levelsHeadquarters.

of tsunami. Moreover, additional research

objectives include (v) putting in place standards regarding
structural requirements for tsunami evacuation buildings;(4) Project Implementation Measures That Contribute todeveloping a system for the provision of information that

Improving Community Disaster-resistanceenvisages the area and depth of tsunami inundation and

In order to ensure that soft measures such as warnings

can be useful in making decisions about issuingand evacuation are sufficiently effective in avoiding andevacuation advisories; and developing a simulator that

reducing the damage from natural disasters, it iscan evaluate evacuation safety and areas that constitutenecessary to improve the ability of the community to

obstacles, as well as methods of formulating urban plans

prevent

that make use of this simulator.

including awareness of disaster prevention among local

disasters(community

disaster-resistance),

citizens and their ability to take action to prevent and(3) Methods of Envisaging Damage Due to a Large-scale

mitigate disaster. Community disaster-resistance differs

Earthquake and Measures Focused on Prevention,according to the attributes of the area and the age

Emergency Response, and Recovery

structure of local citizens, so this research focuses on

In the event of a large-scale earthquake, it is envisaged

analyzing cases from a variety of areas and establishingthat various events would occur that could be a major

methodsofdetermining

each

community's

obstacle to the evacuation of citizens and the provision ofdisaster-resistance. Moreover, using past research

emergency support, such as the destruction and collapse

outcomes, it also seeks to provide public facility managersof road structures and buildings alongside roads due towith supportive knowledge, so that they can establish

the effects of seismic motion or tsunami, as well as theschemes for improving community disaster-resistanceblockage of roads by rubble and vehicles abandoned on

through the implementation of projects under normal

the road. This research focuses on establishing methods

circumstances.

of envisaging the degree to which road transport functions
would be reduced by such events and the damage that

(5)

these reduced transport functions would cause. It also

Techniques Related to Tsunami and High Tide

seeks to use these techniques to propose measures toCountermeasures at Ports

prevent earthquake damage, emergency measures to be

Comprehensive

CoastalDisasterPrevention

In order to build a society that can tenaciously

implemented in the aftermath of a quake, and effective

withstanddisasterandachieve

recoveryandmethods of implementing recovery measures.

reconstruction swiftly in its aftermath, we need to establish

Moreover, in the event of a large-scale earthquake

initiatives that blend hard measures focused on coastal

involving a large amount of damage over an extensive

protection infrastructure, with soft measures such as thearea, whereas there is likely to be a prolonged information

provision of information and evacuation measures. Those

hiatus until data on checks on infrastructure can beinitiatives should be based on the lessons of the Greatgathered, a swift initial response is absolutely vital. This

East Japan Earthquake and the evaluation of local

research seeks to develop methods of estimating

vulnerabilities.

reasonably precisely the extent of the damage to facilities

Accordingly, this research is aimed at the development345

of comprehensive coastal disaster prevention techniques

external forces. This will make it possible to secure roadfocused on port districts. For this purpose, it is necessary

network functions systematically and rationally in theto understand damage spreading processes fromevent of a major disaster.

coastal areas and to find methods for the evaluation
thereof as well as evacuation simulations.

(8) Methods of Maintaining Sewerage Services in the
Event of an Earthquake or Tsunami(6) Systematization of Methods for Evaluating Airport

Following the Great East Japan Earthquake, damage

Disaster Countermeasures

to sewage treatment plants due to the massive tsunami

In light of the Great East Japan Earthquake, thisand damage to sewerage pipes caused by liquefaction

research seeks to gain deeper envisagement of disasters

across an extensive area led to sewerage services beingthat require the use of airports for emergency response

suspended in some areas and service levels being

and disasters that affect airports themselves, and to

reduced in others. Accordingly, the goal of this project is tosystematize methods of evaluating exiting disasterdevelop techniques that will be reflected in the businesscountermeasures including emergency response plans

continuity plans of sewerage providers, as well as

relating to airports, while incorporating such newtechnical standards for facilities.

envisagement. It is anticipated that the systematization
will encourage airport managers, whether in the public or(9) Methods of Verifying the Safety Performance ofprivate sector, to review and improve existing disaster

Buildings in the Event of an Earthquake and Fire

countermeasures for their airports and to standardizetheseprocesses.

Consequently,

theAmid a situation in which it is deemed to be almost

above

certain that an ocean trench megaquake will occur within

systematization will lead to the optimization of disasterthe next 30 years, this research seeks to gather andcountermeasures relating to airports nationwide andanalyze seismic observation records from both within andcontribute to the development of a disaster-resistantoutside buildings, and to propose methods of improving

nation.

the precision of seismic force evaluations, in order toreflect the more advanced seismic motion information(7) Approaches to Performance Requirements for Road

available today in the design seismic forces for buildings.

Structures in Relation to Large-scale Earthquakes

This will facilitate the development of more efficient

During the Great East Japan Earthquake, it wasearthquake countermeasures to prepare buildings

necessary to impose traffic restrictions in many places,

against a megaquake. Moreover, even in the case of

due to damage caused by the seismic motion andbuildings that would have no risk of collapse due to fire ortsunami, including the washing away of road bridgeof fire spreading throughout the building under normal

superstructures, the collapse of the embankment behindcircumstances, it is still necessary to take intoabutments, deformation of retaining walls, extensive

consideration the fact that such risks might arise as aliquefaction,theresult of damage due to an earthquake. Accordingly, thisemergence of level differences. In the meantime

secured efficiently even in the event of a major disaster,

research involves accumulating experimental data
concerning the fire-resistance of medium and high-risebuildings in the aftermath of an earthquake, andformulating guidelines for considering how those inbuildings where confusion is anticipated should react.

this research seeks to systematize performance

Furthermore, surveys and research will be conducted

requirements tailored to the role of each road section,with a view to increasing the sophistication oftaking into account the period required for emergency

tsunami-resistant design and seismic design in light of therepair, and to propose design techniques and measures

Great East Japan Earthquake.

road

surfacesubsidence,andvariations were seen between structures in terms of thetime required to carry out emergency repairs. In relation tothis, in order to ensure that road network functions can bethat should be taken into account according to eachperformance requirement, such as methods of setting

(10)
346

Research

Concerning

Liquefaction

Countermeasures and Evaluation Techniques

providing exemptions from the constraints of the zoning

In relation to liquefaction, there is a lack of adequate

code (obligation to ensure road abutment, setback

measures that can be applied in urban areas that havedistance, building coverage ratio, etc.) in the Building

already been developed. Moreover, in relation to longStandards Act when rebuilding in densely built-up areas

pieces of infrastructure such as levee, it is necessary tothat are dangerous in terms of disaster prevention. Thisdevelop more advanced methods of identifying the areas

research focuses on developing tools for simple

where measures are required, in order to curb the costs

projection and evaluation of the performance of individual

and time required to implement such measures. In

districts at present and in relation to various proposals for

addition, in order to ensure that measures focused on

rules on rebuilding (fire safety, performance as a living

sewerage pipes are effective, it is necessary to clarify theenvironment), and drawing up guidelines for theconditions for the application of existing measures, as wellformulation of harmonious rules on rebuilding that can be

as construction management standards.

provided to local governments, in order to promote theAccordingly, this research focuses on (i) developing

use of this special rules. Through this, it aims to promote

simple methods of evaluating liquefaction risk that can belandowner-led rebuilding in densely built-up areas

applied to residential land, and building up technical data

through the use of the special harmonious rules forand examining integrated countermeasures for streets

rebuilding, as well as increasing the disaster-resistance ofand residential land, with a view to measures to countersuch areas and improving the living environment.

the re-liquefaction of land in areas affected by the Great
East Japan Earthquake, as well as disaster prevention on(12) Conservation and Creation of the Environment inresidential land throughout the country. (ii) With regard to

Coastal Areas

levee, research will be conducted with a view to making

In managing coastal environments where a variety ofidentification methods for sections to be strengthened

physical, biochemical, and social phenomena overlap, it ismore precise and summarizing the applicability ofessential to implement integrated management that takes

countermeasures for levee sections in various conditions,

into account the unique environmental and social

as well as developing a manual of relevant measures. (iii)

conditions in that particular place. Accordingly, thisIn relation to roads constructed immediately on the

researchground (flat section), this project involves analysis of thephenomena in various spatial scales and assessing theirrelationship between liquefaction and geotechnicalmutual dependence, as well as developing evaluation

conditions of the ground and paving, and deliberations

techniques suited to integrated coastal management andconcerning measures to deal with this, as there were

methods of creating frameworks for cooperation andcases during the recent disaster in which it took a longcollaboration among related bodies. These outcomes willtime to reopen the roads to traffic as liquefaction had

be able to be used to put together systematizedcaused differences in level to emerge, even on flat

techniques relating to the integrated management ofsections of road. (iv) With regard to sewerage pipes, thiscoastal areas. Moreover, it will be possible to use theseresearch project involves summarizing the case in which

techniques to make proposals for multiple environmental

countermeasures were not effective and the conditions ofremediation techniques that can be utilized in thetheir application, and examining methods of selecting

reconstruction of coastal areas devastated by the Great

construction methods tailored to the conditions at theEast Japan Earthquake.

focusesonevaluating

environmental

actual site, as well as the construction management ofeffective measures and quality control techniques.

(13) 24/7 Gathering, Analysis and Use of Road TrafficData(11) New Support Methods of Promoting Improvement for

There are cases in which the five-yearly road traffic

Disaster mitigation in Densely Built-up Areas

census is not sufficient for the implementation of focused,

The "special harmonious rules for rebuilding" involves

efficient road-related policies including effective use of our

local governments giving permission for relaxing or

existing roads. Accordingly, this research examines347

methods of supplementing and integrating conventionally

At present, measures in relation to the anticipatedcollected data on traffic volumes and travel speed with the

Nankai Trough earthquake are a matter of urgency for thedata that can be gathered 24/7 from vehicle detectors, cargovernment. Accordingly, developing a research systemnavigation systems with communication capabilities, andbased on the lessons from the recent disaster is a vital

ITS spots, sharing and accumulating this data efficiently,

task in promoting research activities that will assist inand sharing it for use in a wide range of fields, including

mitigating the damage and protecting the lives of theroad traffic management, with a focus on facilitating apeople, in the event of a major disaster that is expected tosmoother flows of traffic, a better road environment, trafficcause even more immense, extensive damage.

safety, and responses in the event of disaster. ThroughIn addition, as well as gaining an accurate

this, it will become possible to cut data collection costs

understanding of the technical tasks required in the field in

substantially and carry out multifaceted, detailed analysis

the event of disaster, through such activities as providing

and evaluation of road-related policies and the priority

technical guidance as a TEC-FORCE unit, it is necessarylevel and effectiveness of road projects.

to strive assiduously to promote research to enable us tomeet these needs.

Thus, the content of our activities has been revised
in light of our experiences of the recent Great East
Japan Earthquake and our research topics cover awide range of fields. It is necessary for us to promote
initiatives in relation to these individual research topics.
In addition, we have become conscious once more of
the importance of initiatives aimed at sharing
information in a way that transcends the boundaries
between fields, and resolving common issues.
Moreover, we have developed a renewed awarenessof the importance of continuous technical support
tailored to the situation in each area.

References
1) National Institute for Land and InfrastructureManagement: Research Policy, July 2012
http://www.nilim.go.jp/lab/bcg/housin/housin24.pdf

As well as the key topics highlighted in the Research
Policy, the following initiatives will also be important tasks
for the future, from this perspective.
(i) Disaster-resistant, resilient community and urban
development planning that optimizes land use,
infrastructure development, and soft measures.
(ii)

Preparations

forcomplexdisasters

involvingearthquakes, tsunami, and fire.
(iii) Methods of accelerating the gathering, sharing, andprovision of disaster information, as well as for risk
communication with citizens.
(iv) Securing dwellings, including temporary housing, in
the immediate aftermath of a disaster, establishing a
housing reconstruction plan and implementing swift
recovery and reconstruction in accordance with thisplan, and enhancing livelihood support for disastervictims.
(v) Enhancing initial response systems in relation tocomplex and major disasters.
348

Afterword
This report provides a chronological summary of the surveys, analyses, research, andtechnical support in the field that NILIM implemented during the first 18 months after theGreat East Japan Earthquake, as well as outlining its initiatives to tackle new challenges
that became apparent in the aftermath of the disaster. The aim of compiling this informationin chronological order is to be able to provide a comprehensive, multidisciplinary overview
of the phenomenon-focused and practical aspects of the disaster. In conducting surveys
and research, NILIM has received assistance from a great many people, especially staff
from the Ministry of Land, Infrastructure, Transport and Tourism headquarters, the Tohoku
Regional Development Bureau, and Iwate, Miyagi and Fukushima Prefectures. Moreover, avariety of research institutes have also assisted us in these endeavors, including the Public
Works Research Institute, the Building Research Institute, and the Port and Airport
Research Institute. We at NILIM would like to take this opportunity to express our sincere
gratitude for their assistance.
All 14 of NILIM’s departments and research centers have been involved in thecompilation of this report, summarizing the aspects of the disaster on which they focused intheir research. As well as covering a wide range of content, this report features as many
multidisciplinary initiatives as it was possible to include. Rather than merely being a recordof the disaster, we believe that this publication has a very important meaning in terms ofbuilding the imaginative abilities that we, as researchers, should have. The content is highly
beneficial not only to those who were directly involved in responding to the disaster, butalso to those who were not directly involved, as it will aid preparations for future disasters.
We at NILIM hope that this report will be read by as many people in the world as possible.
Almost two years have passed since the Great East Japan Earthquake. The
reconstruction process is expected to necessitate terrible hardship and effort. NILIM is
actively providing technical support for reconstruction initiatives, and intends to continue toprovide the necessary technical support.
Furthermore, preparations for a Tokai-Tounankai-Nankai earthquake and an earthquake
directly under Tokyo are also an issue of the utmost urgency. In this sense as well, we at
NILIM hope to learn various lessons from the recent earthquake and tsunami, and conduct
the necessary surveys and research swiftly, so that appropriate front-line support can beprovided in future as well.

349

Reference Material
Table - Reference 1: Teams Sent to Sites by TEC-FORCE, etc.
No.

Teams sent and their activity details

1

At the request of the Tohoku Regional Development Bureau, a two-member river team was sent to survey
the embankment damage of Eaigawa and Narusegawa rivers (March 11-14, 2011)2

At the request of the Tohoku Regional Development Bureau, a two-member bridge team was sent to survey
bridge damage such as on National Highway No. 45 (March 11-14, 2011)3

At the request of the Tohoku Regional Development Bureau, a two-member road disaster prevention teamwas sent to provide technical assistance in coordinating road disaster information for the local emergency
response headquarters of Tohoku Regional Development Bureau (March 11-14, 2011)4

At the request of the Housing Bureau, a one-member building construction team was sent to survey theceiling of the Ibaraki Airport Terminal Building (March 12, 2011)

5
6
7
8
9
10
11
12
13
14
15
16
17
18

To understand the status of incidents like landslides, a one-member erosion control team was sent to Miyagi
Prefecture (March 12, 2011)
At the request of the Tohoku Regional Development Bureau, a two-member erosion control team was sent toFukushima Prefecture to understand the landslide situations, etc. (March 12, 2011)
A one-member sewer team was sent to Miyagi Prefecture to survey the sewer damage and help establish thelocal headquarters, etc. (March 12-15, 2011)
At the request of the Civil Aviation Bureau, a one-member airport team (pavement) surveyed damages to
Sendai Airport (March 13-15, 2011)
At the request of Ibaraki Prefecture, a two-member erosion control team was sent to Mito City, to provide
guidance for landslide disaster prevention facilities on steep slopes (March 14, 2011)
A two-member sewer team was sent to Miyagi Prefecture, to survey the sewer damages and to help
establish the local headquarters, etc. (March 14-15, 2011)
At the request of the Tohoku Regional Development Bureau, the Second Bridge Team was sent to examine
the damaged bridges (March 14-16, 2011)
At the request of the Housing Bureau, a three-member building construction team did a building damages
survey in Miyagi and Fukushima prefectures (March 14-16, 2011)
A two-member building construction team was sent to Ibaraki Prefecture, to survey building damages (March
15-16, 2011)
At the request of the Tohoku Regional Development Bureau, a one-member port team (tsunami, design) was
sent to survey the damages to Sendai Airport and Sendai Shiogama Port, etc. (March 15-19, 2011)
At the request of the Tohoku Regional Development Bureau, the Third Bridge Team was sent to evaluate
damaged bridges (March 16-18, 2011)
At the request of the Tohoku Regional Development Bureau, a three-member ports team (earthquake andtsunami) was sent to Kamaishi Port and Kuji Port etc to survey the damages (March 16-19, 2011)
At the request of the Ibaraki Prefecture, two bridge experts were sent for bridge evaluation in the north of
Ibaraki Prefecture (March 17, 2011)
At the request of the Sabo Department, a one-member sediment control team was sent to survey the
sediment disaster in Miyagi, Iwate and Fukushima prefectures (March 18 & 29, 2011)19

A three-member river team was sent to survey the status of the damages to embankments near the mouth of
the Shin Kitakami River, etc. (March 18-20, 2011)20

A two-member sewer team was sent to Miyagi Prefecture, to survey the sewer damages and to help theestablish the local headquarters (March 18-22, 2011)

350

21

At the request of the Tohoku Regional Development Bureau, a two-member sea coast team was sent toprovide technical assistance, such as a damage survey of Sendai Bay coastal embankment (March 19-20,
2011)

22

A three-member earthquake disaster prevention team was sent to Ibaraki Prefecture, to survey the disastersituation in areas around strong earthquake measurements. (March 21, 2011)

23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38

39

A two-member sewer team was sent to Miyagi Prefecture, to survey the sewer damages and to help
establish the local headquarters (March 21-25, 2011)
At the request of the Civil Aviation Bureau , a two-member airport team (pavement) surveyed the damages to
Sendai Airport (March 21-27, 2011)
A one-member building construction team was sent to Ibaraki Prefecture, to survey the building damages(wooden construction) (March 23, 2011)
A two-member sewer team was sent to Miyagi Prefecture, to survey the sewer damages and to help
establish the local headquarters (March 24-28, 2011)
A two-member building construction team was sent to Fukushima, Miyagi and Iwate prefectures to survey thebuilding damages (reinforced concrete construction, etc.) (March 24-26, 2011)
A one-member building construction team was sent to survey the building damages in Chiba and Ibaraki
prefectures (Ground) (March 24, 2011)
A one-member building construction team was sent to survey the building damages in Tochigi and
Fukushima prefectures (wooden construction) (March 24-25, 2011)
At the request of the Kanto Regional Development Bureau, a three-member sewer team was sent to Ibaraki
and Chiba prefectures to survey the damages (March 24-25, 2011)
At the request of Iwate Prefecture, a two-member sea coast team was sent to assist in surveys of the tsunami
traces height and embankment damages in Taro Town, etc. (March 27-30, 2011)
A one-member ports team was sent to Iwate Prefecture , to survey the tsunami damages to the port (March
27-30, 2011)
At the request of the Tohoku Regional Development Bureau, a one-member sea coast team was sent toprovide technical guidance on survey of tsunami traces (March 28-30, 2011)
At the request of the Tohoku Regional Development Bureau, a two-member bridge team was sent to survey
the damaged bridges in Fukushima City (March 29, 2011)
A two-member building construction team was sent to Iwate and Miyagi prefectures, to survey the tsunami
damages to building (March 30-April 2, 2011)
A one-member building construction team was sent to Ibaraki Prefecture, to survey the building damages(steel frame construction under the old earthquake resistance standards) (March 30-31, 2011)
At the request of the Kanto Regional Development Bureau, a one-member building construction team wassent to Chiba Prefecture, to survey the housing restoration (March 31, 2011)
At the request of the Kanto Regional Development Bureau, a two-member sewer team was sent to Chiba
Prefecture, to survey the liquefaction damages (March 31, 2011)
At the request the Housing Bureau, a one-member building construction team was sent to Miyagi and Iwate
prefectures, to ascertain the damage and to collect basic information to consider measures such as
immediate emergency restoration etc. (March 31- April 3, 2011)40

A two-member earthquake disaster prevention team was sent to Miyagi and Iwate prefectures, to survey thedamages in areas around strong earthquake measurements (April 1-5, 2011)41

At the request of the Tohoku Regional Development Bureau, a two-member port team (tsunami, design) was
sent to survey the damages to Onahama Port and Soma Port, etc. (April 5-7, 2011)42

At the request of the Kanto Regional Development Bureau, a one-member ports team (tsunami) was sent tosurvey the damages to Kashima Port and Ibaraki Port, etc. (April 5-6, 2011)

351

43

A one-member sewer team was sent to Miyagi Prefecture, to survey the damages to sewer system (April 5-7,
2011)

44

A two-member sewer team was sent to Ibaraki Prefecture, to survey the damages to sewer system (April 6,
2011)

45

A one-member bridge team was sent to jurisdiction of the Tohoku Regional Development Bureau, to survey
the damaged bridges (April 5-7, 2011)46

A three-member building construction team was sent to Miyagi Prefecture, to survey the tsunami damages tobuildings (wooden structure) (April 6-8, 2011)47

A one-member building construction team was sent to Iwate Prefecture, to survey the tsunami damages tobuildings (April 6-9, 2011)48

A four-member sediment control team was sent to Miyagi Prefecture, to survey the risks of sedimentdisasters (April 7-8, 2011)49

At the request of the Tohoku Regional Development Bureau, a two-member dam team was sent toFukushima and Miyagi prefectures, to survey the deformations of dams (April 7-9, 2011)50

A one-member building construction team was sent to Ibaraki Prefecture to survey the damages to thebuildings (steel construction) (April 11-12, 2011)

51

A four-member sediment control team was sent to Miyagi and Iwate prefectures, to survey the risks of
sediment disasters (April 11-12, 2011)52

At the request of the Tohoku Regional Development Bureau, a one-member ports team (facility design) was
sent to Kashima Port and Ibaraki Port, to ascertain the damages (April 12-14, 2011)53

At the request of the Sabo Department, a two-member sediment control team was sent to Fukushima
Prefecture, to survey the actual situation of sediment disaster (April 13, 2011)54

A two-member sea cost team was sent to Fukushima Prefecture, to survey the damages to coastal
conservation facilities (April 13, 2011)55

At the request of the Tohoku Regional Development Bureau, a two-member bridge team was sent to Iwate
and Miyagi prefectures, to survey the damaged bridges (April 13-16, 2011)

56

A two-member building construction team was sent to Miyagi and Fukushima prefectures, to survey thedamages to the buildings (ground) (April 15-16, 2011)57

A three-member building fire-safety team was sent to Iwate and Miyagi prefectures, to survey the damages tobuildings (fire) (April 20-22, 2011)58

A one-member building construction team was sent to Ibaraki Prefecture, to survey the damages to thebuildings due to seismic movement (wooden construction) (April 21, 2011)59

A three-member building construction team was sent to Miyagi and Fukushima prefectures, to survey thedamages to the buildings (April 21-22, 2011)60

A two-member building fire-safety team was sent to Aomori and Iwate prefectures, to survey the damages tothe buildings (fire) (April 26-28, 2011)

61

A one-member building construction team was sent to Miyagi and Tochigi prefectures, to survey thedamages to the buildings due to seismic movement (wooden construction) (April 27-29, 2011)62

At the request of the River Bureau, a one-member team was sent to Yamagata and Miyagi prefectures, tosurvey the deformation of dams (April 27-28, 2011)

63

A two-member sewer team was sent to Iwate Prefecture and Miyagi Prefecture, to survey the coastal
conservation facilities (May 2-4, 2011)64

A one-member ports team was sent to Aomori Prefecture, to survey the tsunami damages to port (May 8-9,
2011)

65

A two-member sewer team was sent to Chiba Prefecture, to survey the damages to sewer system (May 11,
2011)

352

66

A two-member sewer team was sent to Miyagi Prefecture, to survey the damages to sewer system (May11-12, 2011)67

A one-member building construction team was sent to Fukushima, Tochigi and Ibaraki prefectures, to survey
the damages to the buildings (reinforced concrete construction) (May 11-14, 2011)68

At the request of the Sewerage and Wastewater Management Department, a six-member sewer team wassent to Fukushima and Miyagi prefectures, to survey the damages (May 23-24, 2011)

69

A one-member building construction team was sent to Iwate Prefecture, to survey the damages to thetsunami damages to buildings (wooden construction) (May 24-27, 2011)70

A three-member earthquake disaster prevention team was sent to Chiba Prefecture, to survey the disasteraround strong earthquake measurements (May 26, 2011)71

A two-member sewer team was sent to Fukushima Prefecture, to survey radioactive sludge of the seweragetreatment plant (May 27, 2011)72

A two-member sewer team was sent to Chiba Prefecture, to survey sewer system damages (March 31,
2011)

73

A two-member building construction team was sent to Miyagi Prefecture, to survey the damages to thebuildings (seismic isolators) (May 31- June 2, 2011)74

At the request of the Housing Bureau, a one-member housing team was sent to the Tohoku Regional
Development Bureau, to assist in the construction of temporary housing (June 11-18, 2011)75

A one-member ports team was sent to Ibaraki Prefecture, to survey the tsunami damage to the port (June 13,
2011)

76

A two-member sewer team was sent to Miyagi Prefecture, to survey the damage of the sewage system (June
15-17, 2011)77

A two-member port team was sent to Iwate Prefecture, to survey the tsunami damage to the coastal
conservation facilities (June 16-17, 2011)78

A two-member sewer team was sent to Ibaraki Prefecture to survey damages to sewer system (June 21,
2011)

79

A one-member building construction team was sent to Iwate Prefecture, to survey tsunami damages tobuildings (June 30-July 2, 2011)80

A one-member building construction team was sent to Ibaraki Prefecture, to survey the damages to thebuildings (gym) (July 1, 2011)81

A one-member sewer team was sent to Fukushima Prefecture, to survey the sewerage treatment plantdamages (July 4, 2011)82

A one-member building construction team was sent to Ibaraki Prefecture, to survey the damages to thebuildings (steel frame construction) (July 6, 2011)83

A three-member sewer team was sent to Ibaraki Prefecture, to survey the damages to sewer system (July13, 2011)

84

A two-member sewer team was sent to Chiba Prefecture, to survey the damages to sewer facilities (July 15,
2011)

85

A two-member port team was sent to Miyagi Prefecture, to survey the tsunami damage to the coastal
conservation facilities (July 19-20, 2011)86

A two-member sewer team was sent to Miyagi Prefecture, to survey the damages to sewer system (August
17-19, 2011)87

A one-member river team was sent to Miyagi Prefecture, to survey the river and coastal sites (August 22-23,
2011)

88

A one-member building fire protection team was sent to Miyagi Prefecture, to survey the fire safety of thegovernment facilities (August 29-30, 2011)

353

89

A two-member port team was sent to Miyagi Prefecture, to survey the tsunami damage to the coastal
conservation facilities (August 31- September 1, 2011)90

A four-member sewer team was sent to Miyagi Prefecture, to survey the sewage system damages and tosurvey the damages to quake-resistant pipes and drains (September 12-14, 2011)91

A one-member building construction team was sent to Miyagi Prefecture, to survey the tsunami damage to
public housing (September 22-24, 2011)92

A one-member sewer team was sent to Iwate Prefecture, to survey the damages to sewer system (October
11-12, 2011)93

A five-member river team was sent for the field survey of the Kitakami, Naruse, Natori and Nanakita rivers(October 11-13, 2011)94

A one-member building construction team was sent to Miyagi Prefecture, to do a detailed survey of tsunami
damage to private housing (wooden construction) (October 13-15, 2011)95

A two-member earthquake disaster prevention team was sent to survey the actual condition of evacuationsites (October 13-15, 2011)96

A one-member sewer team was sent to Ibaraki Prefecture, to survey the sewerage treatment plant damages(December 8, 2011)97

A two-member sewer team was sent to Miyagi Prefecture, to survey the sewerage treatment plant damages(December 8, 2011)98

A two-member sewer team was sent to Miyagi Prefecture, to survey the sewerage treatment plant damages(December 15-16, 2011)99

A one-member sewer team was sent to Miyagi Prefecture, to survey the sewerage treatment plant damages(January 11, 2012)100

A one-member sewer team was sent to Miyagi Prefecture, to survey the sewage system damages (January
16-17, 2012)101

A two-member river team was sent to do a site survey of the Kitakami River (February 5-6, 2012)102

A two-member sewer team was sent to Chiba Prefecture, to survey the sewage system damages (February
14, 2012)

103

104

A seven-member earthquake disaster prevention team was sent to survey the disaster responses of the roadadministrators and support responders and related organizations, after the earthquake (February 29-March 2,
2012)
A one-member sewer team was sent to Miyagi Prefecture, to survey the sewerage treatment plant damages(March 14-15, 2012)354

List of Reference Web Site Addresses
1. Earthquake and Damages
1) Japan Meteorological Agency: [Earthquake and Tsunami Disaster Bulletin] 2011 Tohoku Pacific Offshore
Earthquake
http://www.jma.go.jp/jma/kishou/books/saigaiji/saigaiji_201101/saigaiji_201101.html
2) MLIT: White Paper on Land, Infrastructure, Transport and Tourism in Japan 2010
http://www.mlit.go.jp/hakusyo/mlit/h22/index.html
3) MLIT: The Great East Japan Earthquake, Disaster Information (116th Report), March 12, 2012
http://www.mlit.go.jp/saigai/saigai_110311.html
4) National Police Agency of Japan, Emergency Disaster Countermeasures Headquarters: Damage Situation and
Police Countermeasures associated with 2011Tohoku Pacific Offshore Earthquake, March 19, 2012
http://www.npa.go.jp/archive/keibi/biki/higaijokyo.pdf
5) Fire and Disaster Management Agency, Headquarters for Disaster Control: 143rd Report of the 2011 Tohoku PacificOffshore Earthquake, September 28, 2012 (Friday) 17:00
http://www.fdma.go.jp/bn/2012/detail/691.html
2. The Great East Japan Earthquake and Responses to This by the National Government, MLIT, and NILIM
1) Great East Japan Earthquake Reconstruction related Legislation
http://www.reconstruction.go.jp/topics/120312relevant%20legislation%23.pdf
2) Committees established by the government
2011 Tohoku Pacific Offshore Earthquake, Headquarters for Emergency Disaster Control
http://www.bousai.go.jp/1info/higashinihon_taisaku/index.html
Experts Panel on Countermeasures for Earthquakes and Tsunamis based on Lessons Learned from Tohoku PacificOffshore Earthquake
http://www.bousai.go.jp/jishin/chubou/higashinihon/index_higashi.html
Study Committee for the Promotion of Disaster Prevention Countermeasures
http://www.bousai.go.jp/chubou/suishinkaigi/index.html
Nankai Trough Huge Earthquake Countermeasures Study Working Group
http://www.bousai.go.jp/jishin/chubou/taisaku_nankaitrough/index.html
Nankai Trough Huge Earthquake Model Study Group
http://www.bousai.go.jp/jishin/chubou/nankai_trough/nankai_trough_top.html
Working Group to Study Countermeasures against Earthquakes Directly Under Tokyo
http://www.bousai.go.jp/jishin/chubou/taisaku_shutochokka/index.html
Study Group on Models of Earthquakes Directly Under Tokyo
http://www.bousai.go.jp/jishin/chubou/shuto_chokka/index.html
Working Group on evacuation countermeasures in case of a tsunami (Working Group on Tsunami Disaster
Prevention)
http://www.bousai.go.jp/jishin/chubou/taisaku_tsunami/index.html
3) MLIT: Record of the Great East Japan Earthquake - Disaster countermeasures by MLIT -, March 11 ,2012
http://www.mlit.go.jp/saigai/kirokusyu.html
4) NILIM web site: Great East Japan Earthquake related Information
http://www.nilim.go.jp/lab/bbg/saigai/h23tohoku/index.html
3. Ground Motion
1) NILIM web site: Seismograph network information of facilities such as rivers and roads
http://www.nilim.go.jp/japanese/database/nwdb/index.htm
2) National Research Institute for Earth Science and Disaster Prevention web site: Strong motion observation networks

355

(K-NET, KiK-net)
http://www.kyoshin.bosai.go.jp/kyoshin/
3) Earthquake Research Center Promotion Headquarters: Long-term evaluation of trench type earthquakes
http://www.jishin.go.jp/main/p_hyoka02_kaiko.htm
4. Tsunami
1) Tohoku Pacific Offshore Earthquake and Tsunami Joint Survey Group
http://www.coastal.jp/ttjt/index.php
2) NILIM web site: Great East Japan Earthquake related Information
http://www.ysk.nilim.go.jp/oshirase/uc.html
http://www.nilim.go.jp/lab/bbg/saigai/h23tohoku/index.html
3) Aomori Prefecture web site: Aomori Prefecture earthquake and tsunami damage forecast survey
http://www.bousai.pref.aomori.jp/kansoku/higaisoutei/higaisoutei_top.htm
4) Iwate Prefecture web site: Iwate Prefecture earthquake and tsunami simulation and damage forecast survey
http://www.pref.iwate.jp/~hp010801/tsunami/yosokuzu_index.htm5) Miyagi Prefecture web site: Fourth Miyagi Prefecture earthquake damage forecast survey
http://www.pref.miyagi.jp/kikitaisaku/jishin_chishiki/H22_disaster_prevention_council_bukai/index.htm6) Fukushima Prefecture web site: Summary of Fukushima Prefecture tsunami forecast survey results
http://wwwcms.pref.fukushima.jp/pcp_portal/PortalServlet?DISPLAY_ID=DIRECT&NEXT_DISPLAY_ID=U00000
4&CONTENTS_ID=19543
7) River Tsunami Countermeasures Study Committee, Simulation results of tsunami run-up along rivers, Handout 2
http://www.mlit.go.jp/river/shinngikai_blog/kasentsunamitaisaku/index.html
8) Geospatial Information Authority of Japan: Disaster related information
http://www.gsi.go.jp/BOUSAI/ h23_tohoku.html
9) MLIT, Tohoku Regional Development Bureau, Embankment restoration of Kitakami River, etc., Technical Review
meeting material
http://www.thr.mlit.go.jp/ Bumon/B00097/K00360/taiheiyouokijishinn/kenntoukai/shiryou2_1.html
5. Liquefaction
1) MLIT Press Release: Study results of the “Liquefaction Countermeasures Technology Study Group,” August 31,
2011
http://www.mlit.go.jp/report/press/kanbo08_hh_000154.html
6. Sewage
1) Technology Study Group on Earthquake and Tsunami Countermeasures for Sewerage
http://www.mlit.go.jp/mizukokudo/sewerage/crd_sewerage_tk_000170-1.html
7. River1) Study Group on Countermeasures for Tsunami Run-up along Rivers: “Urgent Proposal on Countermeasures for
Tsunami Run-up along Rivers”
http://www.mlit.go.jp/report/press/mizukokudo03_hh_000376.html
2) Urgent Study Group for River Embankment Seismic Resistance Actions
http://www.jice.or.jp/sonota/t1/201110240.html
3) Technology Study Group for Estuary Barrage/ Water Gate Taking into Account the Tohoku Pacific Offshore
Earthquake
http://www.jice.or.jp/sonota/t1/201106150.html
4) Kitakami River Embankment Restoration Technology Study Group
http://www.thr.mlit.go.jp/Bumon/B00097/K00360/taiheiyouokijishinn/kenntoukai/index.htm

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5) Kanto River Embankment Restoration Technology Study Group
http://www.ktr.mlit.go.jp/bousai/bousai00000057.html
8. Shore and Coast
1) 2011 Act No. 123, Act on Regional Development for Tsunami Disaster Prevention, December 14, 2011
http://www.mlit.go.jp/sogoseisaku/point/tsunamibousai.html
2) MLIT, Water and Disaster Management Bureau, Seacoast Office, NILIM, Coast Laboratory, Handbook for setting
tsunami flooding estimates (ver. 2.00) October 2012
http://www.mlit.go.jp/river/shishin_guideline/bousai/saigai/tsunami/shinsui_settei.pdf
3) Technology Study Group on Regional Development for Tsunami Disaster Prevention, Technology Study Report on
Regional Development for Tsunami Disaster Prevention, January 27, 2012
http://www.mlit.go.jp/river/shinngikai_blog/tsunamibousaitiiki/houkokusyo_120127.pdf
4) Enforcement notice, Director-General for Cabinet Policy Planning Policies (Disaster Management Director), Directorof Policy Research, MLIT, Land Economy and Construction and Engineering Industry Bureau Director-General, City
Bureau Director-General, Water and Disaster Management Bureau Director-General, enforcement of Act on
Regional Development for Tsunami Disaster Prevention, etc., March 9, 2012
http://www.mlit.go.jp/common/000204849.pdf
9. Roads
1) MLIT / Water and Disaster Management Bureau:
Disasters which Occurred in 2011, MLIT, Public works under jurisdiction, Public works facility damage reportsummary
http://www.mlit.go.jp/river/toukei_chousa/bousai/saigai/kiroku/pdf/h23_houkoku.pdf
2) Cabinet Office: 2011 Tohoku Pacific Offshore Earthquake (Great East Japan Earthquake)
http://www.kantei.go.jp/saigai/pdf/201208281700jisin.pdf
3) 2011 Tohoku Pacific Offshore Earthquake civil engineering facilities survey early report, NILIM Material No. 646,
Civil Engineering Material No. 4202, July 2011
http://www.nilim.go.jp/lab/bcg/siryou/tnn/tnn0646.htm
10. Ports and Harbors
1) NILIM web site: Great East Japan Earthquake related Information
http://www.ysk.nilim.go.jp/oshirase/uc.html
http://www.nilim.go.jp/lab/bbg/saigai/h23tohoku/index.html
2) MLIT: Council for Transport Policy, Ports Subcommittee, Disaster Prevention Group
http://www.mlit.go.jp/policy/shingikai/s303_kouwanbousai01.html
11. Architectural Sector
1) National Research Institute for Earth Science and Disaster Prevention: Strong motion observation network (K-NET,
KiK-net)http://www.kyoshin.bosai.go.jp/kyoshin/
2) Japan Meteorological Agency: Strong motion (2011 Tohoku Pacific Offshore Earthquake)
http://www.seisvol.kishou.go.jp/eq/kyoshin/jishin/110311_tohokuchiho-taiheiyouoki/index.html
3) MLIT: MLIT’s Strong Motion Observation Port and Airport Authority (Port and Airport Technical Research Institute
Ground Construction Department)
http://www.eq.pari.go.jp/kyosin/
4) Tokyo: Earthquake motion observed at Tokyo Port Authority Seismic Station
http://www.kouwan.metro.tokyo.jp/business/kisojoho/jishindou.html
5) NILIM: Explanation of requirements on structures such as tsunami evacuation buildings (Document No. 673 of357

NILIM) March 2012
http://www.nilim.go.jp/lab/bcg/siryou/tnn/tnn0673.htm
12. Housing Sector
1) Promotion Council for Regional Restoration Housing
Iwate Prefecture: www.hukkoujuutaku.sakura.ne.jp/
Miyagi Prefecture: www.hukkoujutaku.com/
Fukushima Prefecture: fukushima-hukkoujuutaku.org/
2) Japan Housing Finance Agency - Great East Japan Earthquake special web page
http://www.jhf.go.jp/shinsai/index.html
3) Building Research Institute 2011 Tohoku-Pacific Ocean Earthquake special web page
http://www.kenken.go.jp/japanese/contents/topics/20110311/index.html
13. Cities and Towns
1) MLIT web site: Summary of study survey on techniques of tsunami damaged urban area restoration from the Great
East Japan Earthquake
http://www.mlit.go.jp/toshi/toshi-hukkou-arkaibu.html
2) MLIT web site: Study and survey for reconstruction of liquefaction stricken urban
areas due to the Great East Japan Earthquake
http://www.mlit.go.jp/toshi/city/sigaiti/toshi_urbanmainte_tk_000004.html
3) NILIM web site: Publication of “Effects and Impacts of Lowering the Groundwater Level - Quick Calculation Sheet”
for countermeasures against liquefaction of soil undertaken in the region (trial version)
http://www.nilim.go.jp/lab/bcg/sokuhou/file/120801.pdf
4) MLIT web site: Decisions on issues in adoption of “FY2011 Supplementary Budget Construction Technology
Research and Development Assistance Program” “Earthquake Response Type Technology Development Offering”
http://www.mlit.go.jp/report/press/kanbo08_hh_000169.html
5) MLIT web site: Decisions on issues in adoption of 2012 Construction Technology Research and Development
Assistance Program
http://www.mlit.go.jp/report/press/kanbo08_hh_000189.html
6) NILIM web site: Measuring the effectiveness of the countermeasures against liquefaction by the drain columnar(Experimental results overview)
http://www.nilim.go.jp/lab/jbg/takuti/20120509gaiyo.pdf
14. Parks and Green Spaces
1) NILIM: “Technical Guidelines on the Development of Parks and Greenery pertaining to Recovery from the Great
East Japan Earthquake”
http://www.mlit.go.jp/report/press/toshi10_hh_000097.html
15. Research activities of NILIM
1) NILIM: Research policy, July 2012
http://www.nilim.go.jp/lab/bcg/housin/housin24.pdf

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