Annual Report
2018

Port and Airport Research Institute Annual Report 2018

Message from the Director General
Creating Technologies That Contribute to the World

Message from the Director General

In April 2016, the Port and Airport Research Institute (PARI) restarted as amember institute of the National Institute of Marine, Port and Aviation Technology, which had been established after the integration of PARI, National
Maritime Research Institute and Electronic Navigation Research Institute.
PARI serves as a research institute responsible for developing technology
related to construction and maintenance of ports and airports, and coastalzone management. The Port and Harbour Research Institute (PHRI), thepredecessor of PARI, was established in 1962 as an independent institutionof the Ministry of Transport. Since then, we have provided technical support
for various port and airport projects, including the development of Kashima
Port and the construction of Kansai International Airport, and have maderesearch achievements that are highly regarded throughout the world. In order to maximize the achievements in research and development, we further
expand and strengthen our cooperation and interaction with researchers in
different fields including the two other institutes.
This annual report summarizes PARI’s track record in FY 2017, the second year of the first mid-term plan (from FY 2016 through FY 2022). In thisplan, PARI is focusing on the following four research and development challenges: Coastal Disaster Mitigation and Restoration, Formation of Infrastructure for Vigorous Economy and Society, Preservation of Marine Interests andUtilization of Oceans, and Creation and Utilization of Coastal Environment.
In FY 2017, our specific approaches included the following: 1. “Coastal
Disaster Mitigation and Restoration”: we developed diagnosis and countermeasure technologies to improve the disaster-prevention abilities of petro所長（理事）chemical complexes. To develop numerical simulation models of tsunamiYoshiaki KURIYAMA, Director General, PARI
induced fires, we conducted a comparison between simulation models andexperiments of drift behaviors; 2. “Formation of Infrastructure for Vigorous
Economy and Society”: we investigated the structural health monitoring system for port facilities to inspect and diagnose infrastructure; 3.
“Preservation of Marine Interests and Utilization of Oceans”: we conducted verification studies of deep sea/shallow water underwater acoustic video cameras; and, 4. “Creation and Utilization of Coastal Environment”: we developed a new coastal-ecosystem model that enables toestimate both the amount of blue-carbon (the carbon stored in marine and coastal ecosystems) in various coastal areas and that of oceanwave attenuation due to ecosystem.
In executing the above research, PARI pursued its two major goals of maintaining PARI’s research levels at the highest global standards
and assisting working projects with PARI’s research results. PARI also promoted government-led strategic international activities including
contributing to the expansion of infrastructure overseas and providing technical assistance to overseas countries.
On April 1, 2017, we newly established the Productivity Improvement Research Center to enhance the technological development for
improving the productivity of ports and airports in a cross-sectional manner within PARI. On October 1, 2017, the Ocean Infrastructure Research Center was re-named as Ocean Infrastructure and Offshore Wind Energy Research Center to provide technological support for thepromotion of marine development and utilization, which is one of Japan’s most important policies. At the same time, we strengthened ourtechnological support activities to promote the introduction of offshore wind-power generation, which also entered the implementation phasein Japan recently.
Two years have passed since the Kumamoto earthquake; however, natural disasters including earthquakes and high waves continually occur. We offer emergency responses and restoration support at the time of coastal disaster including earthquakes, tsunamis and storm surges
and conduct awareness activities regarding disaster prevention.
We would greatly appreciate your continued support.

栗山 善昭

CONTENTS
・・・02p1 Outline of Organization
・・・03p2 Management Strategy
3 Structure of Research Themes in FY 2017 ・・・04p
4 Research Themes and Activities in FY 2017 ・・・05p
5 Fundamental and Exploratory Research ・・・14p

01 PARI Annual Report 2018・・・19p
6 Published Research Papers
・・・20p7 Public Relations
8 Outstanding Research Activities ・・・21p
・・・22p9 PARI Events

PARI Annual Report 2018

Outline of Organization
Administrative Staff and Researchers, and Budget

Commissioned research income, etc.
1,433 million yen
FY 2018
Annual Budget
2,645 million yen

Total
98

Researchers(with PhD)
40

Operational subsidies
1,188 million yen

Outline of Organization

Researchers(Others)
41

Administrative staff
17

Facilities maintenance expense subsidy
24 million yen

As of April 1, 2018 (In Yokosuka)

Organizational Structure
President

Distinguished
Researchers

Strategic Planning andManagement Office

Auditors

National Institute of Maritime,
Port and Aviation Technology

Vice Presidents(In Yokosuka)

Administration Department

Planning Department

Administrative Coordination andDisaster Prevention Department

Administrative Division(In Yokosuka)
National Maritime
Research InstitutePort and Airport
Research Institute

Director for Research PlanningElectronic Navigation
Research InstitutePlanning, Coordination and Disaster Prevention Division
Facilities Division
Wave Group

Coastal and Ocean Engineering Department

Maritime Structures Group
Coastal and Ocean Development Group
Marine Information Group

Fellow

Marine Information and Tsunami Department

Managing Director for
Research Affairs
Senior Director forInternational Affairs

Coastal and Estuarine Environment Department

Senior Director for Research

Geotechnical Engineering Department

Marine Environmental Information Group
Tsunami and Storm Surge Group
Coastal and Estuarine Environment Group
Coastal and Estuarine Sediment Dynamics Group
Soil Mechanics and Geo-Environment Group
Soil Dynamics Group
Soil Stabilization Group
Foundations Group

Earthquake Disaster Prevention Engineering Department

Engineering Seismology Group
Earthquake and Structural Dynamics Group
Structural Mechanics Group

Structural Engineering Department

Materials Group
Pavement Group

Sensing and System Technology Group
Frontier Technology and Engineering Department

Robotics GroupInternational Research Center for Coastal Disasters

Oil Spill Response Group

Life Cycle Management Research Center
Ocean Infrastructure and Offshore Wind Energy
Research Center

Reorganized on October 1, 2017

Productivity Improvement Research Center

Established on April 1, 2017

As of April 1, 2018

PARI Annual Report 2018 02

Management Strategy

Management Strategy

Mid- and Long-Term Objectives(FY 2016 to FY 2022)

Mid- and Long-Term Plans(FY 2016 to FY 2022)

The Minister of Land, Infrastructure, Transport and Tourism(MLIT) sets mid- and long-term business goals for the National Research and Development Agency, National Instituteof Marine, Port and Aviation Technology to achieve. These
goals stipulate our operations as follows.

The MLIT sets mid- and long-term goals. In response tosuch goals, the National Research and Development Agency,
National Institute of Marine, Port and Aviation Technology setsmid- and long-term plans to achieve the goals. Among suchplans, important points in maximizing research and development results and improving the quality of other projects are
outlined below.

Basic Policies for Structural Reform of Independent Administrative Institutions were decided in a Cabinet decisionon December 24, 2013 (hereafter called “Basic Policies for
Reform”). Based on these policies, the National Maritime
Research Institute, Port and Airport Research Institute,and Electronic Navigation Research Institute, which were
National Research and Development Agencies operated
under the jurisdiction of the MLIT, were integrated into the
National Institute of Marine, Port and Aviation Technology(hereafter called “PARI”) to implement the policies.
Article 2, paragraph 1 of the Act on General Rules stipulates as follows: some clerical tasks and business require
sound implementation from the viewpoint of general welfare including stabilization of people’s life and socioeconomy, but at the same time do not require government-led implementation. Some of these clerical tasks and businesses
face the risk of neglect when their operation is entrusted to
private entities, so PARI was established to effectively andefficiently conduct their operation.
In consideration of the previous roles of each institution,
PARI is required to continue to make full use of its accumulated wealth of knowledge and stature, and to proceedwith research and development according to the Basic
Policies for Reform. In addition, PARI will constantly review
research contents and select research areas to addresschanges in the social environment. At the same time, PARI
will more actively engage in research and development
activities to solve policy challenges in each field, such as
conducting research in emerging fields.
PARI has promoted research and development in eachfield, cultivated technological seeds, and accumulated specialized knowledge. Thanks to PARI’s legacy, such multidisciplinary research became viable. In consideration ofthis background, PARI will efficiently and effectively implement multidisciplinary research including “Promoting theprotection of maritime interests and the utilization and application of marine-resource/marine-renewable-energy development and other projects”. Through such implementation, PARI will help put national policies into practice.
Furthermore, PARI considers that it is important to returnthe benefits achieved through research and development
to society, as well as to cooperate with external institutions
and to widely disseminate research results. In addition,
PARI is committed to strategically implementing international activities as follows: active participation in projects toformulate international criteria and standards; international
promotion of Japanese technologies and systems throughinternational cooperation; and other activities.
As outlined above, PARI’s missions are based on the
MLIT’s Basic Plan for putting MLIT-recommended policies
into practice. Today, Japan faces various important challenges. By realizing these policies, we can solve such challenges.

03 PARI Annual Report 2018

1. Promotion of multidisciplinary research and other activities
PARI will efficiently and effectively implement multidisciplinary research spanning research fields of the three pre-integration institutions to contribute to putting the following policies into practice: promotion of ocean utilization, enforcementof international industrial competitiveness, and other policies.
2. Research and development of technologies associated withports, shipping routes, coasts, and airports and other activities
PARI will focus on the research and development challenges detailed in the following pages, to devise the following
MLIT-recommended initiatives: disaster-prevention and disaster-reduction countermeasures for port and airport institutions;countermeasures for facility obsolescence of existing structures; and initiatives to create maritime-development hubs.
Among basic research, PARI also actively engages in research to understand the mechanisms of ocean waves andbeach transformation and principles and phenomena regarding the dynamic behavior of the ground and structures.
PARI also uses its foresight and flexibility to accurately address
emerging research which might lead to new research results.
3. Returning benefits from research and development results
to society
PARI will try to resolve technological policy challenges, toaddress disasters and accidents, to enforce bridging functions, to promote and utilize proprietary information, and toenhance the transmission and dissemination of information.
4. Promotion of strategic international activities
PARI will contribute to international normalization and standardization and cooperate with non-Japanese institutions.

PARI Operation Management
PARI will focus on rapid decision-making to engage in strategic institutional operations.
PARI will also hold the following meetings for multi-faceted
investigation of various operational agendas from a broad
perspective:
1. Management strategy meetings: In-house meetings formaking decisions on important issues related to the core principles of PARI management
2. Board of Directors meetings: Weekly meetings involving all
executives and division managers as well as the three directors of the Administrative, Coordination and Disaster Prevention Department
3. Board of Councilors meetings: Meetings to gather insightsfrom independent experts who have broad and deep knowledge
4. External Evaluation Board: An external body in which third
parties objectively and technically evaluate PARI’s research

PARI Annual Report 2018

Structure of Research Themes in FY 2017
Research
Field

Research Theme

Type of Research
Fundamental Research

Strong Motion Earthquake Observation in Port and Airport Area (2A ② )① Research on strong ground motions
and damage predictions in the case of thegreatest earthquakes

Fundamental Research

Investigation of Earthquake Disaster (2A ② )Fundamental Research

Development of strong motion estimation method for scenario earthquakes beneath metropolitan
area

Fundamental Research② Research on damage-reduction
techniques against the greatest
earthquakes

Applied Research
Applied Research

Development of method to seismic peformance evaluation for offshore structure against the largest
earthquake motions③ Research on the interaction ofearthquakes, tsunamis, and high waves
with ground dynamics

Fundamental Research

Seabed Soil Dynamics and Stability Assessment of Breakwaters and Seawalls

Fundamental Research

Study from geotechnical view-point on stability evaluation method of coastal structure subjected tohigh waves (1C ② )① Research on ICT-based decision

Development Research

Development of a tsunami-fire model for ports

Development Research

Development of multi-observation based tsunami forecasting method

1B Research on Mitigation support systems
and Restoration of Tsunami
Disasters② Research on the development oftsunami-resistant ports

Applied Research① Research on storm surge,wave and
1C Research on Mitigation maximum damage estimation
and Restoration of Storm
Surge and Wave Disasters

Development of the estimation method for local scour around coastal structures due to tsunami

Fundamental Research

Elucidation of oceanographic phenomena based on central processing and analysis of observation
data

Development of a harbor tranquility analysis method for local wind waves and ship waves in a harbor

Fundamental Research

Proposal for improvement of prediction accuracy of swell

Applied Research

2. Formation of Infrastructure for Vigorous Economy and Society① Research on technologies for prolonging
the life of infrastructure
2B Research on Life
Cycle Management ofInfrastructures① Research on techniques to improve or
renew existing facilities② Research on effective use andtechniques of treating construction
byproducts③ Research on management andutilization of waste disposal sites at sea

3. P reservation ofMarine Interests andUtilization of Oceans① Research on port construction andmanagement in remote islands
3A Research on
Development andUtilization of Oceans② Research on infrastructure technology
for utilization and development of oceans

4. Creation and Utilization of
Coastal Environment① Research on coastal-ecosystemutilization
4A Research on
Enhancement andUtilization of Coastal
Ecology② Research on the water-environment
simulation and analysis in inner-bay③ Research on countermeasuretechnologies against sea oil spill

4B Research on Coastal
and Estuarine Processes① Research on coastal protection andmaintenance of waterways and mooringbasinsDevelopment of the maritime and environmental simulation model using meso-scale weather☆ forcasting modelA study on the wave force, overtopping, and overflow of wind waves on tsunamis and storm surges
over design water level (1B ② )Development and suggestion of efficient and suitable use which contains automated cargo systems
through container terminal numerical simulations for multi berths
A Research about the CIM (Construction Information Modeling) for Economizing on Manpower, Termof Works, and Cost
Development of evaluation method for performance of reclaimed ground taking into account thedifference in ground improvement method and landfill material (2C ① )Fundamental Research

Evaluation of longterm durability of concrete, steel and various materials based on exposure test

Fundamental Research

Study on the durability of protective coating method for marine steel structures

Fundamental Research
Applied Research

Applied Research③ Research on maintenance andmanagement systems for infrastructure

Estimation of wave transformation around demaged structures to evaluate remaining performance forsheltering

Applied Research

Applied Research② Research on systems for inspecting
and diagnosing infrastructure

2C Research on
Effective Use of Existing
Infrastructure Facilities

Applied Research① Research on strengthening the functions Development Researchof ports and airports to secure international
competitivenessApplied Research② Research on efficient and effective
improvement of ports and airports

A study of seasonal and regional statistics on swell observed in Japanese coast

Development Research

Fundamental Research② Research on the technology to reduce
maximum storm surge and wave disasters

Development of an advanced 3-dimentional simulation model for tsunami inundation

Fundamental Research

Applied Research

2A Research on
Enhancement of Port andAirport Performance forIndustrial Competitiveness

Study on the evaluation and analysis of liquefied ground behavior and effective contermeasures
under sequenced earthquake motions
The diagnosis and countermeasure technique development related to disaster prevention
improvement of industry complex consisting of a wide variety of facilities

Development Research
Development Research

Study on the durability of various materials under severe environments
A study on the improvement of airfield pavement material to prolong the pavement life (2A ② )Development of structural design method for strategic maintenance of port and harbour structures☆ Systematization of repair and strengthening of marine concrete structures
Development of the structural health monitoring system for port structures
Enhancement of ROV system for inspection of concrete superstructures of open-type wharves (2A ① )Applied Research

Study on maintenance planning of port facilities in term of LCC optimization

Applied Research

Development of evaluation method for performance of reclaimed ground taking into account thedifference in ground improvement method and landfill material (2A ② )Fundamental Research

Improvement method to non-uniform ground and its effect as a measure against liquefaction (2A ② )Applied Research

Study on method for evaluation of bearing capacity of piles for upgrade of port and airport facilities(2A ② )

Fundamental Research

Enhancement of accuracy of method for evaluating mechanical properties of composite geomaterials☆ based on microstructural feature

Applied Research

Development of technique increasing capacity of disposal site for dredged soil

Applied Research

Structure foundation for high-degree land-utilization at confined disposal facilities

Development ResearchInnovation for using berthing and mooring facilities constructed in isolated coral reef sea

Development ResearchTechnological development on advanced ship mooring system in port

Development Research

Research on maintenance inspection and investigation technology for remote island ports (2A ① )Development Research

Development of next-generation acoustic imaging system (2A ① )Development Research

Structure of Research Themes in FY 2017

1. Coastal Disaster Mitigation and Restoration

1A Research on Mitigation
and Restoration ofEarthquake Disasters

Item on the Research Agenda(☆indicates special research)

Research Subtheme

Research on adaptation of the machine guidance for an underwater excavator (2A ① )Fundamental Research☆ Field observations and analyses on the formation and stability of carbonate lands

Fundamental Research☆ change

Global estimates of the efficacy of blue carbon as a means of mitigation and adaptation to climate

Fundamental Research

Development of integrated prediction and assessment method of coastal benthic ecology andgeoenvironmental dynamics

Fundamental Research☆ Cross-sectional observation and analysis of atmospheric and oceanographic issues at bay mouths

Fundamental Research

Analytical study of macro-organisms dynamics on a coastal ecosystem simulation

Fundamental Research

Development of evaluating procedure for biodiversity referring to spatial scale in coastal areas

Fundamental Research

Study on the mechanisms of coastal current and water environment using data assimilation

Development Research

Novel oil spill response technology to cope with various sources including natural disaster triggered
oil spills

Fundamental Research

Observation of coastal geographical feature change and generalizing of prediction method in
considered with influence of global warming

Fundamental Research☆ Study on sediment transport in estuary and deposition process in navigation channel

Fundamental Research☆ shoreStudy on applicability of airborne laser bathymetry for topographic monitoring in coastal zone of sea

PARI Annual Report 2018 04

Research Themes and Activities in FY 2017

1A

Research on Mitigation and Restoration of Earthquake Disasters

Background and Objectives

Research Themes and Activities in FY 2017

• To counter large-scale disasters including Nankai megathrustearthquakes and earthquakes in the greater Tokyo area, thefollowing countermeasures are required: securing necessary
trunk line cargo transportation soon after an earthquake andquickly securing the requisite minimum transportation of key
emergency supplies for recovery and reconstruction hubs. In
addition, the interaction of earthquakes, tsunamis, and highwaves with the ground might cause coastal disasters, so it isnecessary to reduce such risks.
• Therefore, the themes of this research cover research anddevelopment which simultaneously achieves the two goals of
improving earthquake resistance and reducing construction
costs. These two goals can be achieved through diagnosis andperformance verification of earthquake-resistance of facilities
which address the properties of long-period and long-duration
earthquake ground motion, which is expected to occur during a
subduction-zone megathrust earthquake, as well as the properties of earthquake ground motion caused by local groundcharacteristics. Research and development are being conducted mainly on methods for investigating and diagnosing earthquake resistance as well as construction methods that improve
the resistance, while using existing facilities with limited design
life that were erected during the era of rapid economic growth.

Research Topics

Research and development comprises the following threesubthemes:i) Research on strong ground motions and damage predictions in the case of the greatest earthquakes
Subduction-zone megathrust earthquakes may cause thegreatest and long-duration earthquake motions, so we will develop techniques for predicting such motions. Also, we will develop techniques for predicting liquefaction and structural damage caused by such motions.
ii) Research on damage-reduction techniques against thegreatest earthquakes
We will suggest the most effective countermeasures under
given limitations to effectively promote seismic strengthening ofexisting structures. In doing so, we will actively utilize damage
reduction and strengthening techniques that use novel materials, structures, and construction methods. Especially, as earthquake-resistance countermeasures for industrial complexes, wewill consider maintaining the functions while reducing costs foroverall plants, and then develop investigation, diagnosis andcountermeasure techniques which minimize usage limitationsof plants. In addition, we will develop testing methods to rapidly
evaluate damage levels on site immediately after a disaster aswell as emergency restoration techniques.
iii) Research on the interaction of earthquakes, tsunamis,and high waves with ground dynamics
We will proceed with research on the following interaction ofearthquakes and ocean waves with the ground: stability evaluation against seabed liquefaction, washout, cavity formation andcollapse under earthquakes or under ocean waves; a mechanism
on how a breakwater foundation loses its bearing capacity in thepresence of tsunami; and other interactions. Also, we will use numerical simulation models, model experiments (on a centrifuge
and a large-scale fluid tank), and other methods to investigate
earthquake-induced submarine landslide development, the resulting tsunami phenomena, ground dynamics under the influence oftsunami and high waves, and the analysis of deformation and instability/destruction mechanisms as well as their countermeasures.
05 PARI Annual Report 2018

Activities in FY 2017

• We obtained 2864 strong motion earthquake records during
the period between January to December 2015. We will organize and analyze these records and will then publish the data
as a Technical Note of the Port and Airport Research Institute.
• In collaboration with related organizations including the Portsand Harbours Bureau of the Ministry of Land, Infrastructure,
Transport and Tourism, we investigated the on-site introduction of a quaywall deformation measurement tool utilizing
RTK-GNSS, which is a technique to assess the post-earthquake damage conditions of port facilities and to determine
whether such facilities can be used.
• To develop a technique to estimate strong ground motions to prepare against large-scale earthquakes occurring directly beneathmetropolitan areas, we analyzed data from several intraslab
earthquakes with different characteristics and then developed
and verified source models to explain those ground motions.
• We conducted a study on the evaluation and analysis of liquefied ground behaviour targeting the sequenced earthquake
motions and grounds involving fine contents, and elucidated
the mechanism of the internal flow characteristics in association with the progress and propagation of liquefied zones.
• To develop diagnostic and countermeasure techniques toimprove the disaster-prevention characteristics of industrial
complexes, we focused on actual coastal industrial complex
facilities and confirmed the earthquake-resistance effects ofthe countermeasure by the model experiment using the National Research Institute for Earth Science and Disaster Resilience’s large shake table (E-Defense) and conducted numerical analyses to re-create the behavior of these facilities.
• We developed a numerical model for steel-pipe members toadequately represent their seismic performance and then proposed a new earthquake-resistant design method, with modified
performance specifications applicable for piled piers, steel pipe
sheet pile quay walls, and anchorages of sheet pile quay walls.
• We took both breakwater mound/ground dynamics against
tsunamis and countermeasure construction against them (reinforcing embankment) into account, and then proposed themethod evaluating the stability of breakwaters.
• We conducted centrifugal model experiments to study the groundstability against waves and found that inter-ground stress and waterpressure affect ground stability. Also, we investigated how to reproduce wave breaking in narrow vessels, in which there is not enough
distance to achieve wave shoaling, and compared the results ofcentrifugal model experiments with fluid numerical analyses.
Canceling effects ofcoseismic crustal
deformation

Deformation near theintended quaywall
Reference point

Observation point

Placing a reference pointout of the effects fromquaywall movement

GNSS receiver(reference point)

Radio antenna

PoleRadio battery

A tool to measure quaywall deformation using RTK-GNSS and trial
measurement at Tsuruga Port

PARI Annual Report 2018

Research Themes and Activities in FY 2017
Research on Mitigation and Restoration of Tsunami Disasters

Research Topics

Research and development comprises the following two subthemes:i) Research on ICT-based decision support systems
We have previously developed a system for rapid forecasting of tsunami inundation, which utilizes offshore-tsunami
waveforms observed by GPS-mounted wave buoys. For highly
reliable tsunami prediction, we will additionally utilize grounddeformation data obtained by on-land GPS base stations andremote-sensing information including ocean HF radars, and willrefine the system. To ensure the safety of evacuation sites, it isnecessary to assess not only tsunami-induced inundation depth
but also the tsunami velocity and floating objects to determine
the resistance of structures and even to assess fires, which areassociated with floating objects. So, we will establish an integrated simulation system which can assess these risks.
ii) Research on the development of tsunami-resistant ports
We will clarify the places with strong flow, scour around structures induced by large-scale overflows, and the impact of drifting objects including ships and vessels. Then, we will develop
a method of designing tsunami-resistant breakwaters and otherfacilities as well as a method of planning tsunami-resistantports. In addition to numerical models we have developed sofar, we will develop a three-dimensional multi-physics numericalmodel based on a particle method with fluid-solid interaction asa tool for the design and planning. Moreover, we will conduct
a large-scale model experiment to validate the robustness andaccuracy of the numerical model, and will understand complex
tsunami phenomena in port cities.

Activities in FY 2017

• In the development of a tsunami-fire model for ports, the generation, transporting, stopping and accumulating processesof debris must be appropriately taken into account; therefore,
we improved a part of the fluid-debris interactions of the existing numerical model. Also, we digitized the location of eachdebris on video images of past experiments and analyzed thecharacteristics of the debris motions.

Vertical configuration

Horizontal configuration

Differences in the motions of debris occurred due to the initial
directions• In the development of multi-observation based tsunami forecasting method, we established a method to improve tsunami
detection accuracy by combining information on satellite positions and filtering processes through continuous wavelet
transform. In addition, we conducted a theoretical analysis todevelop a new tsunami source inversion method, which properly weighs several data with different noise characteristics
including GPS-mounted wave buoys and ocean HF radars.

Research Themes and Activities in FY 2017

• Since the Great East Japan Earthquake in 2011, we havestudied stable structures against tsunami overflows and developed a numerical simulation model to predict the drifting ofdebris generated by the destruction of structures. However,complex behaviors of run-up tsunamis on land and the resulting damages are not fully understood and modeled yet. In
addition, regarding a technique for real-time inundation forecast, which is expected to be utilized for evacuation and otherpurposes, only data from GPS-mounted wave buoys is used;other valuable data is not fully utilized yet.
• Therefore, we are aimed for changing disaster prevention
and reduction countermeasures into a pre-disaster stage
from post-disaster one, and will conduct research to establish
resilient coastal zones which can withstand the most severetsunamis, i.e., to protect lives against the most severe tsunami, to avoid catastrophic socioeconomic damages, and toenable early recovery and reconstruction.

Water level (m)Background and Objectives

Time (minute)

Period (minute)

1B

Continuous wavelet analysis on tsunami water-level data

• In the development of an advanced 3-dimentional simulation
model for tsunami inundation, we introduced a hybrid parallel computation method, which utilizes MPI and OpenMP,
to improve the computation efficiency. Also, we verified thissimulator in the two cities of Kamaishi and Kochi; moreover,
we prepared manuals of this simulator to disclose the sourcecode the next fiscal year, and developed the integrated execution environments including I/O supports tools. In addition,
as a method to properly count the performance of protective
facilities in various damage levels, we developed an evaluation method utilizing fragility curves. We then applied thismethod to Tohoku areas and verified using survey data.
• In the development of the estimation method for local scour
around costal structures due to tsunami, we confirmed the
reproducibility in the topography change according to eachsediment transformation equation by comparing with hydraulic experiments on bathymetry like a port and with the survey
results in and around Hachinohe Port, which was affected by
the 2011 Great East Japan Earthquake.
PARI Annual Report 2018 06

Research Themes and Activities in FY 2017

1C

Research on Mitigation and Restoration of Storm Surge and Wave Disasters

Background and Objectives

Research Themes and Activities in FY 2017

• Since the Ise Bay Typhoon struck in September 1959, there havebeen no devastating storm surge and wave disasters in Japan. However, the U.S. suffered severe damages due to Hurricane Katrina in
September 2005, and so did the Philippines due to Typhoon Haiyan
in November 2013. In future, global warming might bring higher storm
surges and waves than those we have expected in Japan.
• Therefore, this research is aimed for changing disaster prevention
and mitigation measures into a pre-disaster stage from post-disaster one and focuses on how to mitigate damage by the maximum
storm surge and wave conditions and how to rapidly recover andreconstruct after the damage has occurred. Therefore, we conduct
research to encourage hard and soft measures. Specifically, we willdevelop a numerical model to estimate the maximum storm surge
and wave and their damage and will also develop design methods tobuild robust structures.

Research Topics

Research and development comprises the following two subthemes:

width and draft; therefore, the model is expected to be applied forpractical works such as an investigation on the effect of ship waves
on harbor tranquility.
• In the proposal for improvement of prediction accuracy of swell, we
estimated ocean waves around Japan for 3 years by WW3 modelwith 4 types of switches for energy transfer from wind to wave, energy dissipation and other phenomena. As a result, we found thatdifferences develop in wave statistics including the annual averagesignificant wave height.
Average wave height
46°N
44°N
42°N

ii) Research on the technology to reduce maximum storm surge andwave disasters
We will elucidate structural stability under complex conditions inwhich unexpectedly high water level due to storm surge coincides withhigh waves. In addition, we will investigate methods of estimating thedamage on structures due to storm surge and waves and countermeasure against such damages, and develop a method to design robust
structures.

Activities in FY 2017

• In the elucidation of oceanographic phenomenon based on central
processing and analysis of observation data, we summarized the statistical analysis of the wave observation data in 2016 from the Nationwide Ocean Wave Information Network for Ports and Harbours into
an annual report. Also, we analyzed a tsunami in 2016; moreover, we
improved the accuracy of wave data processing.
• In the study of seasonal and regional statistics on swell observed inJapanese coast, we referred to observational wind data to identify
wind waves and swells under the wave directional spectrum and thenvalidated the argument that wind waves generally conform to the relation between the wave steepness and the wave directional spreading,which was proposed by Goda, et al., however, swells do not conform.
• In the development of a harbor tranquility analysis method for local
wind waves and ship waves in a harbor, we modified our ship wave
generation model, in which the locations and courses of ships can be
freely set on 2-D calculation grids, with drawing an estimation chartof coefficients to adjust the ship wave heights which vary dependingon the grid intervals and water depth. With this chart, the coefficientscan be applied to intended ship specifications, such as ship length,

07 PARI Annual Report 2018

44°N
42°N

40°N

40°N

38°N

38°N

36°N

36°N

34°N

34°N

32°N

32°N

30°N

30°N

28°N

28°N

26°N

Monthly maximum
wave height

26°N

24°N

24°N
123°E

126°E
0

i) Research on storm surge, wave and maximum damage estimation
We will develop the following to determine the characteristics of thedamage due to the maximum storm surge and wave: an accurate storm
surge prediction model, which incorporates a weather model; and a new
method based on a 3-D fluid model to simulate tidal levels and flows at
the time of storm surge. Also, we will employ a high statistical analysis
to estimate the effects of global warming on the maximum storm surge
and wave and long-term variations in these statistics. In addition, we
will establish a calculation technique to estimate the following wave
transformations: the wave sheltering effects of breakwaters damaged
through sliding, depression and others; and overtopping prevention effects of seawall having collapsed parapet, dispersed wave-dissipating
blocks and other damages.

Maximum wave height
46°N

Monthly average
wave height

1

129°E
2

3

132°E
4

5

135°E
6

7

138°E
8

141°E

9 10 11 12

144°E 147°E
Hs [n]

123°E

126°E
0

1

129°E
2

3

132°E
4

5

135°E
6

7

138°E
8

141°E

9 10 11 12

144°E 147°E
Hs [n]

Wave statistics estimated by wave model WW3 with switch ST4• In the estimation of wave transformation around damaged structures to evaluate remaining performance for sheltering, we chosesubmerged breakwater with rectangle and trapezoid cross-sections
to conduct model experiments on the wave height transmission
rate and the periodic-modulation rate. On impermeable cross sections, we found wave conditions for periodic shortening associatedwith wave dispersion before breaking which markedly reduce wave
height transmission rates. We confirmed that wave transformation
with trapezoid cross sections can be reproduced by using the existing Boussinesq model. Proper evaluation of port calmness at thetime of breakwater damage is expected to be performed using theabove-mentioned conditions.
• In the development of the maritime and environmental simulation
model using mesoscale weather forecasting model, we used atmospheric pressure and wind predicted by WRF and the Japan Meteorological Agency’s prediction MSM to calculate the storm surge caused
by Typhoon Choi-wan in 2015 in Nemuro and obtained good reproducible results. We used the Isewan simulator, which incorporates
GPV, GSMJP and WRF, to predict short-term environmental change.
• In the study on the wave force, overtopping and overflow of wind
waves on tsunamis and storm surges over design water level, we
elucidated mound transmitted wave force acting on the backside ofseawall and inundation from the mound into the hinterland throughhydraulic experiments. Also, we developed a simple method of estimating overtopping and overflowing rate of the seawall. In addition,
we studied the characteristics of wave force acting on parapets in thecase of wind waves, solitary waves and wind waves with overflow
and overtopping. Then, we classified the wave breakers into breakers under overflow influence, Bagnold-type and Wagner-type and investigated the destruction processes of reinforced concrete.

Reinforced concrete destruction

Experiment of wave force acting on parapets

PARI Annual Report 2018

Research Themes and Activities in FY 2017

2A

Research on Enhancement of Port and Airport Performance forIndustrial CompetitivenessBackground and Objectives

Research Topicsi) Development and suggestion of efficient and suitable use
which contains automated cargo systems through container terminal numerical simulations for multi berths
Focusing on internationally strategic container ports, weaimed to establish methods to effectively utilize Japan’s narrowcontainer terminals. With this goal, we will quantitatively evaluate the effects of off-dock loading/unloading as well as the effects of streamlining operations on reducing environmental burden and preventing congestion in front of gates. Then, we will
use the evaluation results to establish strategies to effectively
and comprehensively utilize container terminals.

lecting a proper route for vehicles. Also, it was shown that thereservation system affects traffic-jam time dispersion and otherphenomena.

On-route traffic jams were observed between the two bridges and gates.

Traffic jams stemming from empty-container repositioning points at MC-3 and MC-4 were observed.

Observation of traffic-jam conditions under simulation. Carefully
devised plans regarding route setting and repositioning points are
required.
(Number of vehicles)

200
180

Activities in FY 2017i) Development and suggestion of efficient and suitable use
which contains automated cargo systems through container terminal numerical simulations for multi berths
We selected Minami Honmoku Pier MC1-4 of Yokohama Portfor the study. In MC1-4, we quantified the number of waiting vehicle in front of gates and its effect on roads outside the terminal
under different hypothetical gate conditions, configuration, handling capacities, and a reservation system through a numericalsimulation using AutoMod.
After the simulation, we learned that, to avoid traffic jams
within wharfs, operators should approach carefully including se-

Case 2A Number of vehicles present on the route between
the waiting-area entrance and the traffic-generating location
Legend:Case sign_Reservation rate (%)_Estimated annual handling of TEU
2A_0_1.7 million

160

2A_100_1.7 million

140
120

Peak control

100
80Time shift

60
40
20

00
9:
00
11
:0
0
13
:0
15 0
:0
0
17
:0
0
19
:0
0
21
:0
0
23
:0
0
1:
00
3:
00
5:
00
7:
00
9:
00
11
:0
0
13
:0
0
15
:0
0
17
:0
0
19
:0
0
21
:0
0
23
:0
0

0
7:

ii) Saving labor, shortening the work period, and reducing
costs by using CIM
As part of construction information modeling (CIM) utilization,
we will use construction-control data from a multi-beam sonar toestablish a construction inspection method. With this method,
we aim to save labor and achieve international standardizationof construction-control inspection. By using CIM, we also aim
to establish unmanned marine construction, in which Japan islagging behind.

Research Themes and Activities in FY 2017

• Focused approaches on the following two matters are required: 1. The population is decreasing, society is graying,
and accumulated infrastructure is aging in Japan. In view ofsuch problems, studies should be conducted on how to secure port and airport functions, which support the international competitiveness of Japanese industry and the vitality of thenation, and people’s lives. 2. With limited financial resources
and workforce, studies should be conducted on how to efficiently and effectively implement maintenance, renewal, andrepair works while efficiently using existing infrastructure andprolonging the life of overall facilities themselves.
• Therefore, we decided to engage in research and development and other activities which are associated with improving the functions of ports and airports. In these activities, weare conducting comprehensive research and development
throughout PARI on subthemes associated with international
competitiveness including internationally strategic port policies and improvement of metropolitan airport functions (improvement of Haneda Airport).
• The themes of this research address the development ofspecific technologies associated with international competitiveness including automated cargo works and construction
information modeling (CIM). Regarding development of technologies which efficiently and effectively implement the following matters for port and airport facilities, the themes of otherstudies (1A, 2B, and 2C) address: improvement of largescale
facilities, improvement of the quake resistance of facilities,
maintenance and management after facility construction, andimprovement of existing facilities.

The example of simulation. Case 2A is a case in which vehicles are
relatively concentrated at one gate. As compared to the green line
(no reservation), the orange line (100% reservation) indicates that the
100% reservation system results in the earlier development of traffic
jams than the no-reservation system; however, on days when vehicle
numbers are relatively small (right), the 100% reservation system iscontrolled its traffic peaks. Regarding traffic-jam causes, the poor traffic capacity of routes in the wharf appears to have a significant effect.

ii) Saving labor, shortening the work period, and reducing
costs by using CIM
The Japan Coast Guard and international institutions, which
regulate marine charts, addressed multi-beam sonar data; however, such operation even at works directly implemented by thegovernment was included in the subjects of the turnover inspection standard from FY 2017. Therefore, government-led operational support was offered.
PARI Annual Report 2018 08

Research Themes and Activities in FY 20172B

Research on Life Cycle Management of Infrastructures

Background and Objectives••

Research Topics

Research and development comprises the following three subthemes:i) Research on technologies for prolonging the life of infrastructure
Regarding various construction materials in marine environments,
we will conduct research on the following: evaluation of long-term durability, understanding of deterioration mechanisms, and investigationof the prevention effects of protective methods for steel structures. Especially, assuming that infrastructure is used overseas and on remoteislands in Japan, we will improve material characteristics and durability
under severe environments and under conditions in which low-quality
material is used, and will investigate environmental-burden reduction,
durability improvement, and environmental coexistence. Regarding
airport pavement, we will investigate methods to detect the strippingof asphalt mixture, measures for prevention of such stripping, the improvement of load-bearing characteristics and the rapid repair methods.
ii) Research on systems for inspecting and diagnosing infrastructure
We will research and develop the following: inspection and diagnosing techniques using non-destructive and semi-destructive inspection methods and sensors, unmanned investigation devices including
ROVs, non-contact thickness measurement system, and others. Especially, we will propose a health-monitoring system which utilizes sensors, as well as monitoring methods specialized for each member type.
In addition, for piers, we will establish a scheme for selecting inspection
and diagnosing methods according to the performance of structures tobe evaluated and the accuracy of expected output.
iii) Research on maintenance and management systems forinfrastructure
We will conduct accelerated deterioration tests of members of port
structures, investigate performance deterioration models which cover
the entire lifecycle of structures, and validate such models through exposure tests in actual environments and through on-site investigation.
We will also take into account the required properties and utilization ofindividual structures, budgets, and various limitations, and then suggest
strategies of management of port-based and district-based groups ofport structures.

Activities in FY 2017

• We will use facilities with long-term exposure to predict chlorideinduced concrete deterioration, and collect data on the durability ofvarious wood materials.
• We aimed to establish a method to predict the deterioration of protective coating methods for steel structures. With this goal, we continuously conducted exposure tests (33 years have passed) regarding
protective coating methods for steel pipe piles at Hazaki Observational Pier. We also conducted accelerated deterioration trials to determine the deterioration mechanisms of petrolatum coating methods.
• We evaluated the durability of concrete, in which low-grade aggregate (gorgonin) and seawater as mixing water had been used andconducted exposure tests to develop a concrete-curing technique using seawater. In addition, we studied exposed specimens to evaluate

09 PARI Annual Report 2018

•

•

•

•

the durability of highly corrosion-resistant reinforcing steel (stainlessreinforcing steel and epoxy-resin reinforcing steel, and others) andsurface coating materials.
We conducted a comparative evaluation through indoor experiments
and other approaches regarding aggregate formulation, warm-mix
materials, fluidity resistance, peel resistance, water permeability, andother characteristics.
We collected and organized cases of repairing concrete at existing structures. Especially, the local failure of caisson-type sidewalls caused by repeated collision of wave-dissipating blocks has
increased in number recently. Therefore, we draw a flow chart toselect the caisson repair method depending on the level of deterioration. Also, we studied the application of a cross-section repair
construction method to prestressed concrete (PC) members withchloride-induced corrosion.
Focusing on breakwater caissons, we confirmed the dominant indicators in determining cross-section types for members designed under the current standard; moreover, we studied lintegrity evaluation
methods when the existing caisson’s life is extended or when the existing caisson is converted to another use as well as considerations
at the time of design and construction.
We proceeded with the following: development of anticorrosion-effectconfirmation sensors; establishment of inspection systems for port
structures; study on proper sensor placement in RC members for efficient corrosion monitoring; development of steel corrosion sensors inconcrete; and investigation of monitoring methods to confirm the effectiveness of new construction methods and materials in pilot projects.
We introduced new operational support functions including a shooting-omission prevention function and an autonomous collisionavoidance function into the ROV for checking the superstructures ofpiers and then conducted on-site verification. Also, we accumulated
data measured through on-site verification on non-contact thickness
measurement; moreover, we investigated on-site seasonal biofoulingconditions and then set usage conditions.
To optimize maintenance and management planning for port facilities, we proposed a priority-setting matrix for maintenance of facilities
based on Net Present Value (NPV) and performance deteriorationlevels. Based on this, we set a model pier, which had been modeled
under the assumption that the pier is 1) the preventive maintenancetype or 2) the countermeasure-priority evaluation management type,
and then conducted case studies of maintenance scenarios, in which
LCC and the profit/loss of a facility during the countermeasure construction period are taken into account.

Preventive
maintenance andmanagement

NPV (100 million yen)

Research Themes and Activities in FY 2017

• The number of port, airport and coastal infrastructures that havebeen used for a long time is increasing, and yet financial resources
and the number of technicians for facility maintenance are limited.
Important port, airport, and coastal infrastructure functions should bemaintained, and so the strategic maintenance, renewal, and otherapproaches for such functions are strongly required.
• Therefore, we will establish design methods for structures and materials which are excellent in terms of maintenance, and will develop techniques regarding various countermeasures in the maintenance phase.

Countermeasure-priority
evaluation management

Optimization of maintenance scenarios for facilities based on NPV and performance deterioration levels

PARI Annual Report 2018

Research Themes and Activities in FY 20172C

Research on Effective Use of Existing Infrastructure Facilities

Background and Objectives••

Research Topics

Research and development comprises the following three subthemes:i) Research on techniques to improve or renew existing facilities
We have already conducted research and development on improving existing facilities including deepening existing quaywalls. However, such improvements were made using techniques for newly-built
structures. Hereafter, we will investigate methods of evaluating groundcharacteristics, design methods, and geotechnical survey methods toimprove and renew existing facilities. In such methods, the construction
history, effects from neighboring structures, and other factors will betaken into account. We will also investigate ground evaluation methods
and geotechnical information databases, both of which cover residual
settlement and other phenomena, with the aim of long-term facility
maintenance and management.
ii) Research on effective use and techniques of treating construction byproducts
We will investigate the following techniques regarding dredged soil:
improvement techniques to transform dredged soil into high-value added materials including composite soil, which provides habitats for benthic creatures, and solidified soil with high water permeability; and newvolume reduction techniques. We will also investigate durability whensolidified soil and slag composite soil are used in sea areas, the mechanical characteristics of composite ground materials containing various byproducts, crushable materials, and other contents, and methodsof evaluating and managing the quality of these materials.

••

based on the following assumption: in the ground, there are several
layers with high fine contents, which result in poor permeability of
the layers. Therefore, liquid chemicals cannot easily penetrate into
the layers.
We aimed to investigate the long-term behavior of piles in soft cohesive soil. With this goal, we conducted model experiments andinvestigated numerical analysis methods. Consequently, through thenumerical analyses, we were able to reproduce the behavior of asingle pile in soft cohesive soil to some extent. Also, regarding improving construction methods for existing pile casting through soil
improvement work between piles, we conducted centrifuge model
tests regarding models of overall cross sections including not only
pile casting but also front sheet piles. Moreover, we verified a modeling method based on numerical analysis of each part for applicationto actual cross sections.
We conducted a compression test of 3D printed specimens in whichshapes and orientations of every particles used for a discrete element model were replicated. With the existing specimen manufacturing methods using 3D printing technique, there were effects ofparticle-to-particle cohesion. Therefore, we investigated a production
method that is free from particle cohesion. Also, using gravel ground,
we developed equipment to conduct on-site X-ray CT scanning of acore sampled from the original location at the same original location.
We investigated volume reduction technique of dredged soil to extend the life of disposal sites through experiment and analysis andconducted numerical analysis investigation regarding the effect ofincreasing the height of a levee on its stability by using the following parameters: the height of dredged soil, distance of a temporarybank from the bulkhead; structure/mechanical properties of temporary banks; and countermeasures for bulkhead bodies. In addition,
we studied volume reduction due to seabed disturbance and foundthat the previously reported effects had been affected by turbulenceat the time of sampling soil specimens. Therefore, the effects might
be reduced to some extent.
We also summarized the results of pile-installation and pile-removal
experiments at a waste site that had been filled with incinerated ash.
We started to investigate an insolubilization of contaminants by cement improvement technique and investigated deterioration promotion methods to study the deterioration of solidification-treated soil
and eluviation of contaminant. As a result, regarding high-earlystrength cement, we achieved homogeneous deterioration of thespecimens by compulsory permeation.

Research Themes and Activities in FY 2017

• There is strong demand to improve the functions of existing infrastructure to enable active, effective use. Requests include countermeasures against increasing logistics volume and larger ships andvessels, expansion of airport functions, and countermeasures against
existing facilities which can no longer be used due to increased external forces and other reasons. In addition, regarding waste disposalsites at sea which accept industrial and non-industrial waste, there
is societal demand to ensure highly effective use of the sites. On theother hand, it has become difficult to secure land for soil disposalsites which accept soil dredged from shipping routes. Accordingly, it
is necessary to prolong the life of soil disposal sites.
• Therefore, we will develop the following: techniques to improve thefunctions of existing infrastructure and to renew and efficiently change
the applications of existing infrastructure; techniques to reduce or effectively utilize construction byproducts and other redundancy; andtechniques to effectively utilize waste disposal sites at sea.

iii) Research on management and utilization of waste disposalsites at sea
Regarding disposal sites at sea, technologies for seepage control
works for site development have been progressed. However, researchon post-construction utilization of such sites has not been conducted.
Therefore, we will investigate the following which are necessary for
utilization: foundations, construction methods, effects on impermeable
layers, management methods of the internal water level at low cost,
techniques to detoxify waste before land reclamation, and the mediumto long-term strength and elution characteristics of solidified soil.

Activities in FY 2017

• Based on measurements of unequal settlement of reclaimed land,
we estimated settlement as we did in FY2016. The coefficients of estimated settlement-curve for FY2016 and FY2017 almost converged.
• By using an experimental system which reproduces a series of processes from a grout injection experiment to an shaking table test
using geotechnical centrifuge, we conducted injection experiments

We studied the effects of particle adhesion. DEM simulation results from uniaxial compression tests (particle overlap at the time of formation = higher overlap
ratio indicates greater uniaxial compression force).

PARI Annual Report 2018 10

Research Themes and Activities in FY 2017

3A

Research on Development and Utilization of Oceans

Background and Objectives

Research Themes and Activities in FY 2017

• Since the 1960s, the importance of marine utilization and development has been pointed out. Various approaches for thispurpose have been taken, but the progress remains inadequate. One of the reasons is the lack of infrastructure at sea asa hub. Therefore, marine hub ports should be constructed onremote islands including Minamitorishima Island and Okinotorishima Island to promote marine utilization and development.
• However, these remote islands are surrounded by severe sea
wave environment and severe sea climate for port construction which are different from those of general ports in main islands. Further technological development is required to ensuresmooth ship berthing, cargo-handling, and port construction.
• Therefore, in this research theme, we will make maximum useof previously accumulated knowledge regarding waves, seabed soils, port structures, and port construction to construct
ports on remote islands, and will also promote marine utilization and development. Specifically, we will clarify the characteristics of waves in isolated reef areas, and will develop a new
mooring system for ships. We will also develop technologies
for downsizing and reducing the weight of underwater acoustic
video cameras, as well as utilization and development.

Research Topics

Research and development comprises the following two subthemes:i) Research on port construction and management in remote islands
We will develop a wave calculation model for wave transformations on continental shelf boundaries and around isolatedislands. We will also propose a technology to create calm water
areas against wave propagation and long-period waves aroundisolated reefs. At the same time, we will develop a new mooring
system applicable to remote islands to improve cargo-handlingefficiency for ships.
ii) Research on infrastructure technology for utilization anddevelopment of oceans
We are trying to downsize and lighten underwater acoustic
video cameras, and will also develop an unmanned underwater
construction system to construct marine infrastructure. In addition, we will propose an environment protection technology bypromoting the attachment of calcifies to structures.

derwater photographs with information including the locationof photographing. Also, regarding methods of measuring thelocation information of an underwater running body, which is
required at the time of management, we proposed a methodof combining acoustic positioning equipment, GNSS, ground
speed meters, and hydraulic gauges. In addition, in a simulated experiment of photographing objects placed in a water tank,
we demonstrated that the dimensions of subjects, deformation,and others can be measured using underwater photographs,
which are taken with the use of parallel line laser radiation.
• In a research on adaptation of the machine guidance for anunderwater excavator, we added an acoustic profiler and decided to conduct pre-measurement of rubble mound shapes.
Also, we conducted unit tests of acoustic positioning equipment at the actual construction site and confirmed that multiple reflection and noise do not have a significant impact. In
addition, we conducted comprehensive tests at Keihin dockyard and confirmed that disparities of seafloor surface coordinates (height) are ±32 mm or less.
• In a development of next-generation acoustic imaging system,
we organized the specifications of deep/shallow underwater
acoustic video cameras as specifications that can withstand realsea-area conditions. Regarding deep underwater acoustic video
camera, we conducted verification tests at Takuyo Daigo seamount, an investigation site near Minamitorishima and then succeeded in taking acoustic images at the depth of 1500 m. Also,
regarding shallow underwater acoustic video camera, we conducted trial operations through public works at Minamihonmoku
and succeeded in taking acoustic images steel pipe sheet piles.
• In a field observations and analyses on the formation and stability of carbonate lands, we succeeded in estimating groundformation rate on scales ranging from several days to seasonsin model site investigations; moreover, we elucidated determinants of calcification rates, which greatly affects the groundformation speed. Also, we used the existing core-sample
specimens and succeeded in estimating the ground formation
rates on a scale of the past 1000 years. With this success, we
proposed a quantitative model of the maintenance conditionsof low-water lines. In addition, in a coral coexistence-type tidepool at Urazoe breakwater of Naha Port, we elucidated thatthe following factors are important environmental conditions
to increase coral coverage: levels of disturbance due to water
depth, water flow, waves; and gradient and shapes (complexity level) of the coral-adhering surface.

Activities in FY 2017

• In an innovation for using berthing and mooring facilities constructed in isolated coral reef sea, we used the coupling model
between a wave hindcasting model (WAM) and a wave transformation model (NOWT-PARI) to estimate the occurrence
frequency of ocean waves around isolated islands. Then, we
compared the estimated occurrence frequency with ocean wave
data from 1-year observations around the Minamidaitojima Island and Kitadaitojima Island and verified the cargo-handling operation rate at quays. Also, we used CADMAS-SURF/3D, which
was improved to simulate moored ship motion, to estimate theoscillation magnitude of each moored ship at isolated reef areas.
• In a technological development on advanced ship mooring
system in port, we devised a suction-connection combination
method, steel mooring fender method, wire strings method,and other methods. Of these methods, we selected the wire
strings method as a highly suitable mooring method underremote island conditions.
• In a research on maintenance inspection and investigation
technology for remote island ports, we proposed a management method. In the method, we associated inspection un11 PARI Annual Report 2018

Design wave

Mooring rope

Ship (690GT)
Supporting pole

Connection arm
Mooring wire
QuaywallWinch [for tension adjustment]

A new mooring system utilizing wires

Geometric measurement using acoustic profilers

PARI Annual Report 2018

Research Themes and Activities in FY 2017

4A

Research on Enhancement and Utilization of Coastal Ecology

Background and Objectives

development of quantitative prediction techniques and mitigation techniques for spilled oil. Through such approaches, we willdevelop innovative countermeasure techniques against oil pollution and improve the ability to respond oil pollution.

Activities in FY 2017ii) Research on the water-environment simulation and analysis in inner-bay
We will develop the following methods regarding the acquisition and utilization of environment observation data: a new methodof analyzing marine monitoring data covering currently operating
ferries and monitoring posts and others; and a new method of
observing parameters for which common methods cannot obtainadequate results. We will also re-analyze existing underutilized
environmental data, and will use multi-functionalized GPS waveobservation buoys to continuously observe areas for which environmental data has not been obtained. In addition, we will integrate
weather/marine/ecosystem models and utilize in real time the environmental observation data. Through these means, we will develop
a system which comprehensively predicts problems that frequently
occur in inner bays, including red tides, blue tides, and hypoxia.

• In a global estimates of the efficacy of blue carbon as a means of
mitigation and adaptation to climate change, we almost completed the establishment of a new coastal ecosystem model which
achieves both blue-carbon quantification in various coastal areas and predictor models of ocean-wave attenuation which takethe ecosystem into account. Also, we organized a nationwide
estimated value of CO2 amount absorbed by blue-carbon ecosystems in both 2013 and 2030, and then made the data public.
• In a development of integrated prediction and assessment
method of coastal benthic ecology and geoenvironmental dynamics, we established and proposed a new method
to evaluate the ground environment dynamics of tidelands
and beaches. Moreover, we succeeded in comprehensively
evaluating the effects of typhoon events on benthic ecosystems and ground environment dynamics. Also, we obtained
positive results regarding unified evaluation of the mechanicalcharacteristics of coral-gravel composite soil.
• In a cross-sectional observation and analysis of atmosphericand oceanographic issues at bay mouths, regarding atmospheric observation, we investigated affordable measurement
methods, used their prototypes, and obtained measurement
results. Also, regarding marine observation, we set a unified
policy regarding the existing systems and a new marine-observation system on Kanaya-maru.
• In a development of evaluating procedure for biodiversity referring to spatial scale in coastal areas, we compared characteristic properties among the habitat environments of several
organisms, and then elucidated that Ebi tideland, an artificial
tideland, is a highly unique (complementary) environment.
• In an analytical study of macro-organisms dynamics on a coastal ecosystem simulation, we added new compartments referring
fishes into the existing model and re-structured it to a new one.
• In a study on the mechanisms of coastal current and water
environment using data assimilation, we could replicate watertemperature on the east side of areas around bay mouth inTokyo Bay, which had not been replicated using a numericalcalculation model alone.
• In a novel oil spill response technology to cope with various
sources including natural disaster triggered oil spills, we investigated the following regarding a technique to prevent the drifting of spilled oil by using bubble curtains: application to port
facilities; application to tsunami fires; and application to oil-collection ships. Also, in the development of oil-leakage real-timehazard maps, we developed an oil drifting simulation by using
network-type hazard maps and a γ-version all-time system forproviding hazard information (trial-operation version).

iii) Research on countermeasure technologies against sea
oil spill
Regarding technologies for dealing with spilled oil, in addition
to developing technologies to resolve conventional on-site challenges, we will conduct new research and development on thefollowing: oil-gathering equipment loaded on next-generation
oil-recovery ships; and systems which comprehensively recoveror treat oil and which can address large-scale oil spill incidents.
In addition, we will establish an information system for the risk
management of oil pollution based on simulation technology,
understand the behavior and mechanisms of oil spilled fromdangerous facilities in waterfront areas due to natural disasters
including earthquakes and tsunamis, and conduct research andComparison of numerical calculation results with data assimilation
results in Tokyo Bay regarding sea-surface temperatures(Left: numerical calculation model; right: data assimilation model)

Research Topics

Research and development comprises the following threesubthemes:i) Research on coastal-ecosystem utilization
Regarding ecosystem-based countermeasures against the
impacts of climate change, we will conduct research on alleviating climate change including carbon separation and storage
and atmospheric CO2 uptake, both of which utilize ecosystems(blue carbon) under various conditions including remote islands
such as Minamitorishima Island. In addition, we will expand ourtechnological development internationally. We will also develop
a technology to create coastal ecosystems which suffer lessdamage due to earthquakes and tsunamis and which recoverrapidly. Through such technologies, we can continuously reap
the benefits of the ecosystem.

Research Themes and Activities in FY 2017

• Rich ecosystems in coastal zones include tidal flats, seagrassmeadows, and coral reefs. Coastal zones are valuable places
for the global environment. However, during the era of rapid
economic growth, intense socio-economic activities caused thedeterioration of water quality in coastal inner bays and enclosed
waters, resulting in ecosystem damage. Thanks to subsequent
countermeasures, water quality has gradually been improving insome coastal zones; however, recovery of the coastal zone environment including ecosystems remains a formidable challenge.
• On the other hand, new challenges include the utilization ofcoastal zone functions for mitigating climate change, as wellas countermeasures against large-scale oil spill incidents
from maritime industrial complexes and other facilities.
• Therefore, in the themes of this research, we will conduct
research and development with the following goals: further
restoration of the coastal zone environment, coastal zone utilization for climate change mitigation, and establishment oftechnologies to counter large-scale oil spill incidents.

PARI Annual Report 2018 12

Research Themes and Activities in FY 20174B

Research on Coastal and Estuarine Processes

Background and Objectives

Research Themes and Activities in FY 2017

• PARI’s research activity of littoral drift was started to examine the critical water depth of sediment movement for harborplanning. Now, prevention methods against sedimentation
and also siltation are proposed. However, in Japan, sedimentation and siltation are still progressing in some ports, andin other countries which aim to expand their infrastructure
overseas, a much greater amount of siltation than in Japan is
projected. Countermeasures against such sedimentation andsiltation problem have been inadequate.
• On the other hand, beaches are valuable as they provide protection, environment and utilization functions. However, the area ofbeaches has been decreasing since the era of rapid economic
growth, and is still shrinking at a rate of 1.6 km2 per year. Various countermeasures have been taken to prevent such coastal
erosion, and as a result, the beach area has increased at somecoasts. Nevertheless, global warming is expected to cause
more severe coastal erosion. In addition, when remote islands
and overseas are taken into account, it is important to maintainnot only beaches but also coral-reef coasts.
• Therefore, in the themes of this study, we aim to maintain thefollowing under future climate change: natural coastline geometry including beaches, mangrove coasts, and coral-reefcoasts; and artificial coastline geometry including navigation
channels and harbor basins, which support logistics. We will
also estimate changes in coastal-erosion and sedimentation
phenomena assuming the progress of global warming, andthen propose countermeasures against those changes. Also,
we will clarify siltation processes in the estuaries of large rivers, mangroves and intertidal zone in the Asian countries, andthen propose countermeasures against such phenomena.

Research Topics

Our researches and developments for coastal protection andmaintenance of waterways and mooring basins are as follows:
We will analyze long-term measurement data of the Hasaki
coast and conduct short-term, intensive, on-site observation of
how beaches respond to different sea levels. Through this, wewill understand beach-response mechanisms to sea level rise,
and will develop methods of predicting future beach morphology. We will take into consideration the spatial scale of not only
the Hasaki coast but also global, and predict long-term coastalchanges (including natural sand coasts, sand coasts protectedby structures, coral-reef coasts, and pebble coasts) along withvariations of coastal disaster risks. In addition, we will develop
hybrid beach-maintenance methods, which minimize structure
volume and actively introduce sand bypasses, and propose effective beach maintenance methods that account for the disaster risks.
Regarding sediment transport which accompanies port utilization, we will expand the scope of our research to include
estuaries of large rivers, mangroves, and intertidal zones overseas. Then, we will develop monitoring method for topographic
change which address regional characteristics and understandthe dynamics of topographic changes. In addition, we will examine strategies to reduce siltation and sedimentation and will develop the efficient maintenance methods of navigation channels
and harbor basins as well as conservation of the surrounding
environment of port and harbor facilities.

Activities in FY 2017

• In an observation of coastal geographical feature change andgeneralizing of prediction method in considered with influenceof global warming, we elucidated the following: changes inshoreline position are associated with both tide and wave
height; the changes occur 36 days after the day when tide
becomes highest and 72 days before the day when wave
height becomes highest. Also, we investigated a wave breaking model for numerical simulation, which utilizes the Ursell
number, which represents the asymmetric characteristics ofwaves, however, the calculation results regarding breakers
on submerged breakwaters and average water-level reduction are sometimes unstable. Therefore, we found that the
breaker model requires further improvement.
• In a study on sediment transport in estuary and deposition
process in navigation channel, we compared the results ofan estuary turbidity distribution study conducted around
Patimban Coast (August, dry season) with the results from aprevious study (February 2017, rainy season), and identified
seasonal-variation characteristics of highly dense fluid mud.
Also, we conducted on-site studies regarding highly dense
turbid water at the time of flowing out within Niigatanishi Portand elucidated the process of accumulation of highly dense
fluid mud in dredging areas. In addition, we conducted on-site
observations and flume experiments, modeled the amount of
fluid mud transport, which depends on mud content in the bottom sediment and other factors, and then verified the model.
• In a study on applicability of airborne laser bathymetry for
topographic monitoring in coastal zone of sea shore, obtained
topography through aircraft sounding utilizing green laser
showed good agreement with the cross-section topography
through lead sounding, except for areas with many whitebubbles caused by wave breaking. Regarding the scouringconditions around piles supporting observation pier of Hazaki
Oceanographycal Research Station, correct measurements
were made. Although some measurement errors, which appear to be caused by missing sea bottom measurements
due to the white bubbles of wave breaking, due to turbidity
in deep-water areas and other factors, aircraft sounding accuracy levels are high, showing that aircraft sounding can be
an effective method of performing highly accurate topographymeasurements within breaker zones on a wider and highlydense scale.

Vertical distribution of bottom-mud densities in rainy season (above)and dry season (bottom) at Patimban

13 PARI Annual Report 2018

PARI Annual Report 2018

Fundamental Research
Cases of Fundamental Research

The fundamental research of waves, beaches, ground, earthquakes,
environments, etc., is the basis of every study conducted by PARI, andtherefore we are actively working on clarifying principles and phenomena, such as the mechanisms of natural phenomena and dynamic behavior of the ground and structures.

Seabed Soil Dynamics and Stability Assessment of Breakwaters
and Seawalls• Seabed ground can flow markedly owing to diverse external loadings such as earthquakes and tsunamis. However, the seabed ground flow dynamics remain largely
unclear, since on-site observations are formidable if not impossible. These submarine
ground dynamics can greatly affect coastal structures; therefore, it is important tounderstand the phenomena and establish an evaluation method.
• The submarine liquefied flow dynamics greatly affect coastal and marine structures aswell as submarine-landslide tsunamis; on the other hand, the dynamics have previously been difficult to predict. In this study, we established new theories and numericalanalysis methods which can predict and reproduce a series of concurrent processes
regarding the submarine liquefied flow dynamics, and then comprehensively validated
their effectiveness. In addition, we elucidated the effects of fine contents and percolation on the development of submarine landslides and the associated gravity flows.
• We systemically elucidated the dynamics of the seabed and rubble mound of caisson
breakwaters under tsunami-induced seepage, regarding focal ground flow dynamics
around coastal structures and its effects. Moreover, for the first time in the world,
we elucidated the mechanism of destabilization of a breakwater caused by tsunami
overflow-seepage coupling. Then, we established a new stability assessment method
for caisson breakwaters that take into account both the dynamics of the breakwater
foundation mound/seabed and countermeasures against them (embankment).
• The developed analytical framework for submarine liquefied flow dynamics can be
widely used for predicting coastal large-scale processes of submarine mass movements and assessing the impacts of the submarine liquefied flows on coastal andmarine structures as well as submarine landslide tsunamis, and thus serve as basisof their rational evaluation and prediction. In addition, the new stability assessment
method of breakwaters considering both the dynamics of breakwater foundation
mound/seabed against tsunamis and their countermeasures, are comprehensively
reflected in the technical standards for ports. Therefore, wider utilization is expected
not only nationally but also internationally.

1

Strong Motion Earthquake Observation in Port and Airport Area

2

Investigation of Earthquake Disaster3

Development of strong motion estimation method for scenario earthquakes beneath metropolitan area

4

Study on the evaluation and analysis of liquefied groundbehavior and effective contermeasures under sequenced
earthquake motions

5

Seabed Soil Dynamics and Stability Assessment of Breakwaters and Seawalls

6

Study from geotechnical view-point on stability evaluation
method of coastal structure subjected to high waves

7

Development of the estimation method for local scour
around coastal structures due to tsunami

8

Elucidation of oceanographic phenomena based on central
processing and analysis of observation data

9

Proposal for improvement of prediction accuracy of swell10

Development of the maritime and environmental simulation
model using meso-scale weather forcasting model

11

Evaluation of longterm durability of concrete, steel and various materials based on exposure test

12

Study on the durability of protective coating method for marine steel structures

13

Study on the durability of various materials under severe
environments

14

Improvement method to non-uniform ground and its effectas a measure against liquefaction

15

Enhancement of accuracy of method for evaluating mechanical properties of composite geomaterials based on microstructural feature

16

Field observations and analyses on the formation and stability of carbonate lands

17

Global estimates of the efficacy of blue carbon as a meansof mitigation and adaptation to climate change

18

Development of integrated prediction and assessment methodof coastal benthic ecology and geoenvironmental dynamics

Triggered by earthquake,ocean waves or otherenvironmental forcings

Liquefied soil(A) Submarine landslide

Entrainment of
ambient fluid

VortexPore wGrading structure

ater migrationSoil stratification

Solidifie
Particlesegregationd soilVoid ratio profile

Consolidation(B) High-density gravity current(C) Deposition
Caisson toe
Horizontal location of scour front at
top surface of the mound : m

Research theme (Fundamental research)

Fundamental and Exploratory Research

Fundamental Research in FY 2017

Washout (boiling)

19

Cross-sectional observation and analysis of atmospheric andoceanographic issues at bay mouths

20

Analytical study of macro-organisms dynamics on a coastal
ecosystem simulation

21

Development of evaluating procedure for biodiversity referring to spatial scale in coastal areas

22

Study on the mechanisms of coastal current and water environment using data assimilation

23

Observation of coastal geographical feature change and generalizing of prediction method in considered with influence of
global warming(a) Scour of the mound/seabed,

24

Study on sediment transport in estuary and deposition process in navigation channel

25

Study on applicability of airborne laser bathymetry for topographic monitoring in coastal zone of sea shore

Elucidation of the effects oftsunami overflow-seepage coupling on
caisson instability

With seepage

Caisson-destabilized
regionWithout seepage

Prototype scale (50G)
mound thickness

Overflow period : s

Tsunami overflow andseepage coupling induced(b) bearing capacity failure,(c) flow of the moundSubmarine Liquefied Flow Dynamics and Their Analytical Framework with Experimental and Field Validations: Conceptual charts

PARI Annual Report 2018 14

Fundamental Research8

Unit: cm (+: deposition, -: erosion)

Model 1

7

[cm]
1

8

Contour interval: 0.2 (cm)

7

0.5

6
0
-0.5

4
3

-1

2

-1.5

1
0

1

2

3

4
5
X[m]

6

7

8

-2

0

5
Y[m]

Y[m]

0.5

6

5

0

[cm]
1

Model 2

-0.5

4
3

-1

2
-1.5

1
0

0

1

2

3

4
5
X[m]

6

7

8

-2

Comparison of geometric change at a landform like a port

Elucidation of oceanographic phenomena based on central processing and analysis of observation data
• PARI has been processing and analyzing ocean wave data acquired by the Nationwide Ocean Wave information network for Ports and HArbourS (NOWPHAS) since1970. With increasing concern about climate change, we must continue this analysis
and provide wave information that is relevant for practical port and coastal works.
• Therefore, in this study, we make out quick and definite information based on data observed at each station on NOWPHAS. We also conduct statistical analyses, compile
annual reports on NOWPHAS and accumulate tide level and wind data. In addition, we
conduct on-site observation using highly accurate capacitive wave gauges, establish
a method to estimate 2-D higher wave number spectra, and develop a method to estimate ocean winds and waves using synthetic-aperture radar including TerraSAR-X.
• In FY 2017, we conducted statistical analyses of ocean wave data obtained in 2016
and compiled the annual report on NOWPHAS. It included the local highest significant
wave heights at 14 stations, consisting of 7 stations having seabed wave gauge (e.g.
Kushiro and Mutsuogawara) and 7 stations having GPS-mounted wave buoys (e.g.
East Aomori). Especially, the high waves caused by Typhoon Lionrock in 2016, which
made landfall in the Tohoku region for the first time since 1951 when the Japan Meteorological Agency started to take typhoon statistics, were observed at many stations.
• Also, we extracted the tsunami waves caused by Off-Fukushima Earthquake on November 22, 2016 and confirmed that the tsunami arrived at the Pacific coast of the
Tohoku region. Especially, the tsunami height was slightly less than 20 cm and ap15 PARI Annual Report 2018

proximately 70 cm at the GPS-mounted wave buoy off the Fukushima coast and thetide station in Sendai-Shiogama Port, respectively.
• In addition, we improved the accuracy of the tsunami profile on a GPS-mounted wave
buoy by an appropriate preprocess of the sea surface elevation data.
• Continuously, we intend to compile annual reports on NOWPHAS, to analyze noticeable tsunami and ocean wave events, and to improve wave data processing andanalysis methods. We also intend to use the results of our work to design port andcoastal facilities and to prevent disasters.
付表−B.1.1

留萌
目

月

1

Ｈ 1/3（ ｍ ）

3.95

5.26

8.2

9.4

2

3

付表−B.4.1

月 別平均および最 大有義波（連続 観測）

6.2

6.9

5.17

5.07

波高

5.83

間

波向

5.83

801 〜

9.7

751 〜 800

12/ 2
15:40

701 〜 750

8.87

7.86

10.25

10.25

651 〜 700

7.4

9.7

9.2

10.1

10.1

601 〜 650

0.39

0.55

2.02

1.67

1.74

1.12

551 〜 600

9.0

8.9

9.7

4‑ 8:20

8‑23: 0

2‑15:40（ ｍ ） 標 準 偏差

0.77

0.84

0.70

0.59

0.44

0.34

0.34

0.25

0.39

1.01

0.94

0.95

0.93

501 〜 550

平 均 値

6.4

6.1

5.6

5.5

5.2

4.5

4.4

4.5

5.1

6.6

6.2

6.3

5.5

451 〜 500

0.86

1.00

0.93

94.40

99.95

100.00（連続観測）

12

8
6

5

6 7 8
（月）

9 10 11 12 通
年

0.82
99.82

0.78

0.96

99.87

99.28

（連続観測）

1.18

1.05

1.14

1.06

1.27

401 〜 450

99.68

99.73

99.68

100.0099.36

351 〜 400

留萌
2016年

40

波高１ｍ以下56.13％
波 高 １ ｍ − ２ ｍ 26.56％
波 高 ２ ｍ − ３ ｍ 12.61％
波 高 ３ ｍ − ４ ｍ 3.57％
波 高 ４ ｍ − ５ ｍ 1.01％
波高５ｍ以上0.12％

周期階級別出現頻度（連続観測）

1

2

付図−B.1.1

0

留萌

3
4
波高（ｍ）

5

6

7

101 〜 125
76 〜 100

0

2

4

6
8
10
周期（ｓ）

12

14

E

ESE

SE

SSE

S

SSW

SW

(

(

126 〜 150

26 〜 50合 計

波 候特性図（連続 観測）

波 高・波向別出現 頻度統計（連続観 測，2016年１月 〜2016年12月）
波 高 ・波 向 階 級 別出 現 頻 度 表（ 有 義 波 ）

ENE

(
2
(
( 0.0)
3(( 0.0)
5(( 0.0)
12(( 0.0)
27(( 0.1)
97(( 0.4)
221(( 0.9)
521(( 2.1)
0
0
0
0
0
0
0
0
888
( 3.5) ( 0.0) ( 0.0) ( 0.0) ( 0.0) ( 0.0) ( 0.0) ( 0.0) ( 0.0) (151 〜 175

1051 〜 750NE

251 〜 300

176 〜 200

20NNE

301 〜 350

201 〜 250

周期４ｓ以下11.71％
周 期 ４ ｓ − ６ ｓ 50.84％
周 期 ６ ｓ − ８ ｓ 34.04％
周 期 ８ ｓ − 10ｓ 3.38％
周 期 10ｓ − 12ｓ 0.03％
周 期 12ｓ 以 上
0.00％

30

20
10

2
4

1.06
100.00

波高階級別出現頻度

30

4

1

1.16
99.95

留萌
2016年

40

10

頻 度 (％ )（％）

頻 度 (％ )率

留萌

2016年 1月 〜 2016年 12月 (年 )

年

4.64

5.4

0.37

月別平均有義波

3

2.43

6.4

3‑15:40 26‑19:40 30‑22: 0

12

2.55

7.1

0.40

平均有義波高平均有義波周期

2

1.48

6.4
1‑18:20（連続観測）

3.44

6.9

0.65

2

1

2.13

7.2
8‑17:40

11

4.01

7.4

0.94

3

0

10

4.07

5.2

1.11

9‑ 7: 0 15‑17: 0

2.33

9

5.23

9.3

1.71

（ ｓ ） 標 準 偏差

得

留萌
2016年

2.32

8

8.10

8.3

1.93

周 期 (ｓ )

測

4

3.16
7.2

7

7.88

8.6

平 均 値

Ｔ 1/3

標 準 偏差

4.76

6

7.40

Ｔ MAX（ ｓ ）Ｔ 1/3（ ｓ ）8.9

5

Ｈ MAX（ ｍ ）起 時 （ 日 ‑時 :分 ） 28‑19:40 15‑18:20

平 均 有義 波

4

最
高
波
Ｈ 1/3

有
義
波

対 応 最高 波

波 高 (ｍ )

留萌

2016年

項

最 大 有義 波

WSW

観 測 地点 ： 留 萌
W

WNW

NW

NNW

㡰఩

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ࡢ㉳᫬

Ἴ㧗 P

࿘ᮇ V

Ἴ㧗 P

࿘ᮇ V

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Off Fukushima(GPS-mounted wave buoy)

Onahama Port

NNW



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࣮࢜࣍ࢶ ࢡᾏపẼᅽ

N

NNE

NW
ENE

WNW

E

W

ESE

WSW

40%

SW
S

NE
ENE
測得率 95.3%
静 穏 15.3%

40%

E

N

NNW

WNW

E

W

ESE

WSW

SE
SSW

留萌
NE

波高(m)
ENE

測得率 97.1%
静 穏 8.9%

SSE

S

2016年 1月〜2016年12月（年）

NNE

NW
ENE

40%

ESE
SW

SSE

2016年 3月〜2016年 5月（春）NE

測得率 95.9%
静 穏 43.3%

SE
SSW

NNE

NW

40%

E

3.00〜
2.00〜 3.00
1.50〜 2.00

SW

SE
SSW

S

ESE
SW

SSE

SE
SSW

2016年 6月〜2016年 8月（夏）࣮࢜࣍ࢶ ࢡᾏపẼᅽὀ 㸧 㹼 ࡣ ๭ ឡ 㸬

(cm)
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N

NNW
NE

測得率 94.9%
静 穏 8.3%

SSE

WSW㧗Ẽᅽᙇ ࡾฟࡋ

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

S

WNW
W

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



WSW

2015年12月〜2016年 2月（冬）༡㧗໭ప ᆺ

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


W

SE
SSW

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WNW

E

ESE

40%

WSW

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測得率 92.3%
静 穏 0.2%W෤ᆺẼᅽ 㓄⨨

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NNE

NW
ENE

合 計

0
( 0.0)
0( 0.0)
0( 0.0)
0( 0.0)
0( 0.0)
3( 0.0)
26( 0.1)
86( 0.3)
180( 0.7)
325
10.0) ( 1.3)
584
230.1) ( 2.3)1204
180.1) ( 4.8)2039
400.2) ( 8.1)1327
440.2) ( 5.3)
1546
560.2) ( 6.2)
1711
790.3) ( 6.8)2137
1300.5) ( 8.5)
2693
1840.7) ( 10.7)
2971
3331.3) ( 11.8)
4443
662
2.6) ( 17.7)
1570 21275
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406
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424
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641
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3254
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2.2) ( 14.6) ( 21.5) ( 12.7) ( 11.0) ( 13.0) ((連 続 観 測 )௜⾲㸫%ࠉ␃ⴌࠉ㧗 Ἴ୍ぴ⾲㸦㐃⥆ ほ␃ⴌ(Doppler-type Wave Directional
Meter; Kaisho-kei in Japanese)

Fundamental and Exploratory Research

Development of the estimation method for local scour aroundcoastal structures due to tsunami• Tanimoto’s formula, the static-pressure formula at the time of overflow, and other formulas have been examined to determine the tsunami wave force to be used in antitsunami design for breakwaters. These study results were published as the Guideline
for Tsunami-Resistant Design of Breakwaters in FY 2013. However, there are manycases of overflow-induced scouring damages such as the case of the northern breakwater of Hachinohe Port during the 2011 Great East Japan Earthquake. These damages have not been fully investigated.
• Therefore, in this study, we conduct hydraulic-model experiments using a movable-bed
regarding breakwaters and their peripheral submarine topography. We vary the sanddeposit conditions including particle diameter and then compare the results. In addition,
we investigate the armoring effects of crushed stones of a mound. Through these investigations, we propose a versatile equation for estimating scouring amount. Furthermore, we investigate a method for estimating scouring amount using a particle method.
• Seafloor topography changes through seafloor sand/mud migration, which is caused bytsunami flow. There are various modes in the migration, including sliding, rolling, saltation, and floating. Several theoretical and experimental equations have been proposed
for each of these modes. The equations for respective modes need to be combined in
the simulation for estimating local scouring amount associated with sediment migration.
• However, the optimal combination for a given phenomenon and the application limitation for the combination have not been fully investigated. In order to establish a modelthat accurately replicates phenomena that affect local scouring, including armoring
effects of crushed stones of a mound, we must first confirm the existing equations
and limitations for each of these combinations.
• Therefore, in FY 2017, we conducted many simulations in which various equations werecombined. We compared the simulations with the results of experiments in which an
artificial tsunami engulfs a landform like a port and with actual tsunami cases including
Hachinohe Port, where focal scouring occurred due to the 2011 Great East Japan Earthquake. Through the comparisons, we organized the geometric changes estimated byeach estimation model and their combinations, and then elucidated their characteristics.
• In the future, we will continue to investigate the similarity laws, and will calculate flow
and seafloor changes using a particle method. After taking the results into account,
we will establish an equation for estimating scouring amount, and then will reflect ourachievements in technical standards and so forth.

付図−B.2.1

SSSE

1.00〜 1.50
0.25〜 1.00

(連 続 観 測 )2016年 9月〜2016年11月（秋）留萌

波 高・波向別出現 頻度図（連続観 測）㐃⥆ほAnnual report on NOWPHAS

November 22, 2016

0

50

0
50cm
-50
6:00

(Legend of Kaisho-kei

7:00

8:00

9:00

Measured by ultrasonic wave

10:00

11:00

Converted from water pressure

Tsunami profiles caused by Off-Fukushima Earthquake in 2016

Study on the durability of protective coating method for marine
steel structures• The combination of two types of prevention methods, namely cathodic protection andprotective coating, has been used for marine steel structures, ensuring their longterm durability. Regarding the protective coating method, deterioration characteristics
including life expectancy have been clarified from the past exposure test results.
However, methods of checking the performance of each protective coating method at
the time of design, methods of evaluating current protective performance at the timeof maintenance and management, and methods of predicting future situations have
not yet been established.
• Maintenance and management costs remain high and there are not enough technicians, so more efficient methods of maintaining and managing the above social
capital urgently need to be developed.
• In this theme, we are working on establishing the following methods: a method tocheck the performance of each protective coating method at the time of design, amethod to evaluate the current protective performance at the time of maintenanceand management, and a method to predict the future situation.
• Investigation (1): We elucidated the deterioration mechanism of the petrolatum coating method and conducted accelerated deterioration tests to establish a method toevaluate the performance of petrolatum material.
• Investigation (2): We conducted field studies on the protective coating construction
method and corrosion at the boundary of the existing concrete superstructure at
Hazaki observation pier.
Concrete

Steel pipe

(Paint was applied after
it was placed in service)

Investigation (1): Accelerated deterioration
tests to establish a method to evaluate the performance of petrolatum anticorrosion material(A steel pipe was wrapped with anticorrosion
materials and rotated in tap water at 60°C.)

Boundary between concrete superstructure andthe existing steel pipes that were painted after
being placed in service.
(Corrosion advanced at the boundary.)

PARI Annual Report 2018

Fundamental Research
Global estimates of the efficacy of blue carbon as a means of mitigation and adaptation to climate change• Climate change countermeasures in port and coastal projects are urgent challenges.
Recently, it is being confirmed that blue carbon (carbon captured by marine organisms) in marine ecosystems is effective for mitigating climate change (atmospheric
CO2 absorption and carbon storage). Also, coastal ecosystems are expected to adapt
to climate change, including dissipating ocean waves and sediment deposition. Therefore, comprehensive investigation of the two functioning is necessary. However, quantification of the extent of dissipation of ocean waves and sediment deposition by coral
reef ecosystems, seagrass beds, and other conditions has only just begun worldwide.
• In the study, we will utilize the ability of blue carbon to mitigate and adapt to climate change
to improve the cost effectiveness of port and coastal projects. Leveraging the improvements to propose new climate change countermeasures, we will develop a method toquantify the mitigation and adaptation functioning of blue carbon against climate change(investigation, analysis and modeling). In addition, using newly developed methods, wewill estimate the mitigation and adaptation functioning at coastlines on a global scale.
• This fiscal year, we conducted the following studies: new establishment of thecoupled mangrove-coral reef ecosystem model, geometric/ecosystem data collection and GIS analyses for estimation on a global scale, and modeling of shallow
coastal ecosystems in terms of wave attenuation and inundation reduction. Also, we
conducted in situ investigations on carbon dynamics at seagrass beds, tide flats,coral reefs, and mangroves both in Japan and overseas. In addition, we led the Blue
Carbon Study Group in Japan, which consists of experts from academia, relatedorganizations, and so forth.

Fundamental and Exploratory Research

Improvement method to non-uniform ground and its effect as ameasure against liquefaction• Countermeasures for earthquakes and liquefaction are now made at ports and airports,
so it is essential to make existing facilities earthquake-resistant. As a construction method
to prevent liquefaction of ground directly under existing facilities and ground surrounding
buried structures, the density increasing method and the chemical grouting method are
frequently used. Generally, when the ground of the original location is heterogeneous andwhen the fine content is relatively high, construction tends to be challenging. But if construction is performed forcibly, problem such as localized deformation at the surrounded
ground will be developed. Therefore, in this study, the improvement effects on heterogeneous ground by the chemical grouting and the densification method are investigated.
• In this study, visualization technique such as a transparent soil was employed to visualize
ground deformation. As the transparent soil, we used crushed transparent quartz particles
and refractive index matching solution to make the model ground transparent. In centrifuge model tests, we simulated grout injection and investigated the effects of different
ground conditions on the improved area.
• This new visualization method is practical, and can visualize complex intraground penetration and deformation behavior, both of which have been challenging previously. Goingforward, we will conduct numerical simulations and other strategies regarding phenomena observed in experiments and will use the results to develop a method to predict ground
improvement effects. Also, this experiment method is expected to be applied to various
geotechnical engineering problems other than ground improvement.

Before saturation

Tidal effects are large

Homogeneous ground

Fine layer 1.0 m

Fine layer 0.25 m

Grout injection processes

Field observations and analyses on the formation and stability ofcarbonate lands• The importance of remote island-based marine development and utilization has been
increasing. The low-water lines of remote islands are the baseline for the exclusive
economic zone. Thus, in order to conserve national land for remote islands, it is necessary to maintain not only territory but also low-water lines.
• Remote islands located in the southern part of Japan including Okinotorishima Islandand Minamitorishima Island have different soils from those of Honshu and other mainislands where the main material is silicates. The soil and sediment of these remoteislands are composed mainly of calcium carbonate formed by corals and foraminifers(calcifiers). Therefore, conservation of the national land depends on whether the rateof formation of land by calcifiers exceeds the rate of the rise of sea level and erosion.
• External stresses including climate changes, bottom-sediment changes, and environmental changes can be not only threats for calcifiers but also threats from theviewpoint of national land conservation.
• Therefore, in this research, we aim to understand the determinants of the groundformation rate by calcifiers as well as the processes of movement, settlement, anderosion of sediment to create a scientific and technological basis for maintenance of
territory, low-water lines, and port facility geometry.
• This fiscal year, we conducted in situ investigations at model sites (Rukansho, Naha
Port, Hirara Port, Ishigaki Port, Akashima Island, Iriomotejima Island, Ishigakijima
Island, and Furenko Lake), and analyzed the existing core-sample specimens. Also,
we investigated the relationship of coral coverage with the environmental conditions
in a coral coexistence-type tide pool at the Urazoe breakwater of Naha Port.
Outside of port

Water passage area

Inside of port

Processing to maketetrapod uneven

Processing to makeconsolidation blocks uneven

Coral symbiosis-type tide pool at the Urazoe breakwater of Naha Port24-hour continuous study of carbon dynamics

Study on sediment transport in estuary and deposition process innavigation channel• In ports located around estuaries, countermeasures against sedimentation of navigation channels and harbor basins due to the deposition of discharged sediments
through rivers are required. Examining countermeasures against sedimentation andsiltation is important research subjects to resolve the following existing challenges:
shortage of disposal site of dredged sediments and reducing the cost of maintenancedredging. Maintaining navigation channel and harbor basins are more serious problems in many ports in Southeast Asian and other countries, which are situated next tocities developed in estuaries of large rivers.
• In this research, focusing on estuaries not only in Japan but also overseas including inSoutheast Asian countries, we aim to understand the transport dynamics of sedimentsupplied by rivers including the transport of highly concentrated fluid mud and its seasonal variations, taking regional characteristics into consideration. We also make a simulation model of these sediment transport processes in the estuarine and coastal zones.
• This fiscal year, in a collaborative study under a joint-study agreement with the Indonesian government agency BPPT,
we studied estuary turbidity distribution around Patimban Coast(August). Also, we conducted
on-site studies of highly concentrated turbid water where theDistance from Bandaibashi Bridge (m)Shinanogawa River flows out into
the estuary and in an area within
ADCP measurement(using ship-body rigs
Niigatanishi Port (November,or river boats)
Downstream side
December). In addition, we con- Upstream side
ducted transport experiments of
Various measuring instruments(AAQ, Mudbug)
local bottom mud transported byAnchor mooring
waves and flows, and quantitatively evaluated changes in transStudies of highly concentrated turbid water
port amount depending on mud
where the Shinanogawa River flows out into thecontent rates and other factors.
estuary and in an area within Niigatanishi Port
Ground level (D.L.±0) (m)After saturation

Saturation processes

PARI Annual Report 2018 16

Exploratory Research
Exploratory Research in FY2017
In FY 2017, 8 exploratory researches based on ingenious and/or advanced ideas and potentially pioneering research fields for PARI in the
future were carried out, considering foresight and mobility.

Fundamental and Exploratory Research

1. Development of educational tools for inspection and diagnosis
using simple VR• Port administrators including local government should be largely responsible for the
maintenance and management of port facilities, but with limited budget and manpower. Therefore, the burden of maintenance and management work is increasing.
As a result, the number of cases in which structural safety has declined due to thedeterioration of structural members resulting in serious accidents, is increasing inaged facilities. In view of this trend, the proper and efficient inspection and diagnosisof port facilities is required. Therefore, in this study, we created educational tools thatenable young technicians and inspectors to study the following easily: mechanisms ofdeterioration and deformation in port structures and inspection points.
• We proposed the following educational tools and methods: 1) 3D animation films foreach type of port structure (piled piers, steel sheet pile quaywalls and breakwaters
covered with wave-dissipating blocks) regarding degradation chain mechanisms. 2)
Important points of visual inspection in pier superstructures by analysis of the viewpoint of skilled inspectors using the viewpoint camera (GoPro). 3) The virtual experience tool for a visual inspection of piled piers using a head-mount display (HMD) andan omnidirectional camera (Gear360). 4) The method of diagnosis in pier superstructure using 3D-development diagrams created by SfM/MVS software.
Pier (substructure)

Damage to anticorrosive coating

Figure 1. 3D animation film

Figure 2. Virtual space experience through HMD

2. Analysis of Visual inspection data of superstructure of opentype wharves using survival analyses• Even at the same open-type wharf, deterioration of the underside of superstructure
is known not to proceed homogeneously. We empirically know that members locatedon the sea or land side tend to deteriorate more progressive, but do not understandwhat factors affect the deterioration progress and to what extent such factors affectthe deterioration progress.
• Regarding facilities subject to technical standards, routine inspection and diagnosis
has become mandatory, and are carried out at least once every 5 years. Routine
inspections include visual inspections, so visual inspection data are expected to accumulate. Regarding visual inspection of the underside of superstructure of opentype wharves, to diagnose the degree of deterioration of all members, analysis ofvisual inspection data of the underside of superstructure of open-type wharves, which
will be accumulated quantitatively, may allow identification of the characteristics that
contribute to deterioration progress. Therefore, in this study, we used the method ofsurvival analysis to analyze visual inspection data of the underside of superstructureof open-type wharves (from 19 open-type wharves) and investigated the factors contributing to deterioration progress.
• After analyzing the visual inspection data, each member type appears to have different factors affecting deterioration progress. As an example, Figure 1 shows an
estimated survival function for each member type depending on the location of members in perpendicular direction to the normal line of an open-type wharf. BH (Figure
1 (a)) shows that members located on the sea or land side tend to deteriorate moreprogressive; BV (Figure 1 (b)) shows no difference in deterioration progress depending on locations of members; S (Figure 1 (c)) shows that members located on the sea
side tend to deteriorate more progressive.

(a) BH (beams in the direction
horizontal to the normal line)(b) BV (beams in the direction
vertical to the normal line)(c) S (floor slab)

Figure 1. Results of an estimated survival function of each member, with locations in perpendicular direction to the normal line of an open-type wharf(Legend: Red = members located on land side of an open-type wharf, Blue = central, Green = sea side)

17 PARI Annual Report 2018

3. Development and evaluation of a storm surge numerical modelusing a Kalman filter• When a typhoon appears, it is important for coastal disaster prevention to conduct
an accurate storm surge forecast (SSF). However, it is difficult to closely observe
meteorological fields in time and space on the open ocean, and the initial values used
for typhoon forecast might greatly cause the difference between the typhoon forecast
and the actual one. Since differences in meteorological fields cause differences instorm surges, the accurate SSF is still a great challenge.
• Therefore, in this study, we used the Regional Oceanic Modeling System (ROMS)
to develop a storm surge numerical model which successively assimilates ocean
observation data. In this model, the calculation is revised every time after observed
values are obtained, and so is expected to suppress differences in prediction fromoccurring. The assimilation method uses the Ensemble Kalman Filter (EnKF), which
derives the analytical value from multiple first guesses with different initial conditions.
• For model verification, we conducted the following twin experiment for the case of
Typhoon Lan in 2017. 1) We calculated the storm surge with the meteorological analytic value MSM-GPV (grid interval: 5 km) as an external force (calculation period:
between 0:00, October 21, 2017 and 12:00, October 24, 2017; calculation area: lat.
22.5° to 47.5° N, long. 125° to 149° E; grid interval: 5 km), handled the results as true
values, and then made the observed values by adding Gaussian noises on the true
values. 2) We used the LAF method to set seven different initial conditions. With eachcondition as a starting point, we calculated the storm surge with the meteorologicalforecast value GSM-GPV (grid interval: 20 km) as an external force. 3) Regarding the
calculations, we assimilated the observed values every hour at points where GPSmounted wave buoys are positioned.
• As a result, we confirmed that theassimilation affected the overallcalculation area, even though theobserved values were given at the
points. However, the assimilation did
not improve forecast accuracy.
• In the future, we will investigate thefollowing optimal model setting: applying the Breeding method for making
new initial conditions, increasing thenumber of ensemble members, and Revision of storm surge by the assimilation
shortening the assimilation interval.
(●: Location of GPS-mounted wave buoys)
4. Attempts to establish a technique for the retrieval of near-surface marine information from GNSS-R• The broad term for positioning satellites, including GPS launched by the UnitedStates, is Global Navigation Satellite Systems (GNSS). Of GNSS, remote sensing
utilizing the phenomenon whereby signals from positioning satellites are reflected on
the sea surface and the land is called GNSS-R (Reflectometry). GNSS-R utilizes existing positioning signals, making simultaneous observation from several sites possible. Therefore, GNSS-R now has excellent potential as a low-cost monitoring method
for natural phenomena that change quickly, including typhoons and bomb cyclones.
• In estimating physical parameters, including sea surface winds, ocean waves, tsunamis, and storm surges, using GNSS-R, we should focus on the following important
points: we will elucidate the physical phenomena of “wavelets” in actual sea areas,
and will then quantitatively evaluate the relationships of such physical phenomena
with dispersion signals from the sea surface.
• In this study, we conducted comprehensive in-situ observations of ocean waves andassociated physical parameters, sea surface winds and wave-induced mixing, at Hiratsuka observation tower, University of Tokyo Ocean Alliance between March 28
and April 5, 2018. Moreover, we used a GNSS antenna to measure the magnitude of
GNSS signals reflected from the sea surface.
GNSS antenna• Going forward, we will analyze the obtained
data. In particular, regarding direct measure- Hiratsuka
observation tower
ment of higher wave number spectra withwavelengths of up to approximately 10 cm andsource balance at their frequency zones, there
are many unknowns. In estimating wavenumber
spectra, the wavelet directional method proposed by Donelan et al. (1996) is used. In addition, we aim to clarify independently the following: the physical processes of the ocean wave
Anemometer andboundary layer using measured ocean wind
wavemeter arrayturbulence; turbulence mixing associated withbreakers using marine surface layer turbulence,and the effects on higher wave number spectra, Observation equipment in Hiratwhich are associated with turbulence mixing.
suka observation tower

PARI Annual Report 2018

Exploratory Research

6. Proposal of an corrosion protection method using a techniqueto form self-assembled monolayers (SAMs)• Epoxy-resin coating and galvanization are direct methods for preventing the corrosion ofreinforcing steel bar as for reinforcing-steel concrete structures. However, these methods
costs more than regular reinforcing steels; therefore, reasonable, simple and highly effective anticorrosion methods are being developed.
• One method to prevent the corrosion of precious metals and highly reactive metals is to confer water repellency by surface modification of reinforcing steel bar using self-assembled
monolayers (SAMs). Surface modification using SAMs is a simple method in which metals
are just immersed in a solution containing functional molecules. Therefore, such surface
modification come to be great advantage for civil structures that use a lot of reinforcing steel.
In this study, we aimed to apply SAM-based anticorrosion techniques to reinforcing steels.
• To confirm the anticorrosion performance of SAMs on reinforcing steel bar, we evaluatedthe following anticorrosion properties: 1) corrosion protection performance confirmed
through accelerated deterioration tests that replicate alkaline environments and salt-damage environments, and 2) corrosion protection performance confirmed through electrochemical measurements.
• Figure 1 shows the results of accelerated deterioration tests involving a cycle of dry and humid conditions. The test specimens with SAM-modified surfaces showed no corrosion in thealkaline environment, but showed corrosion at the first cycle in the salt-damage environment.
• Based on measurements of corrosion speed of the test specimens immersed in seawater(Figure 2), we investigated the effects of SAM on corrosion speed. The results showedthat corrosion is faster in the following order: no SAM > SAM No. 1 > SAM No. 2 > SAM
No. 3 > SAM No. 4. Therefore, we found that corrosion is slower than with no SAM whensurfaces are treated with SAMs in the presence of corrosion. Accordingly, these results
indicated that surface modification with SAM can reduce corrosion speed compared withregular reinforcing steels.
• In future studies, we need to investigate the durability of SAMs and actual anticorrosion
effects by burying test specimens with SAM-modified surfaces in concrete.

Water repellency
Cycle 0

Cycle 14

Cycle 7W

Cycle 4

ith

ou
t

SA
M

Salt-damage environment: dry/humid cycling using seawater

Surface modiﬁcation using SAMs

Figure 1. Confirmation of anticorrosion performance through accelerated deterioration
tests using SAM-modified specimens

Figure 2. Results of corrosion speed measurements

7. Elucidation of mechanisms of earthquake-induced tsunami by
numerical analysis methods• In faults called the decollement zone located in shallow areas of plate subduction boundaries, we observed slow earthquakes in which slip failure proceeds more slowly than regularearthquakes. At the time of an earthquake, if the decollement zone slips fast together withthe earthquake, the slip might evolve into a large earthquake that causes a large tsunami.
Large Nankai megathrust earthquakes are expected to occur, so it is urgently necessary
to clarify the causes of the unstable behavior of the ocean’s crust where slow earthquakes
can develop in the decollement zone.
• Around plate boundaries, clay minerals are known to alter due to high temperature andpressure. Therefore, we aimed to develop a numerical analysis method that expresses
the dynamic changes in soil quality that are accompanied by such clay mineral alteration,and to investigate the dynamic behaviors of the ocean’s crust which alters while bearing
shearing force.
• The results of analyses in which plate subduction was assumed (bottom figure) showedthat gap water pressure increases in the upper areas of the decollement zone, and in
response, the strength of the decollement zone tended to soften after temporary hardening. Hardening causes sticking between plates and softening causes the development ofslow earthquakes. This suggests that clay mineral alteration is a cause of crust varianceresulting in tsunamis.
• Going forward, we will focus on changes in ion density and temperature in decollementzones as these affect the speed of alteration, and will then improve the model.
Accretionary prism(lower layer of continental plate)

Decollement zone

Fundamental and Exploratory Research

5. Development of drift model using arbitrary object• Various models for tsunami-induced drift objects have been developed; however, inthese models, drift objects of various shapes, such as vessels and vehicles, are expressed as mass points, rectangular solids, and combinations of particles. Shibuya
et al. (2012) suggested that the ability to express object shape is important for the
reproduction of trapping phenomenon caused by structures for capturing drift woodin rivers. Drift objects caused by tsunamis have various shapes including vessels,containers, vehicles, and house rubble. Therefore, the ability to express shape is essential for predicting complicated phenomena in which these objects interact.
• Therefore, in this study, we tried to develop a drift model which can express drift objects of arbitrary shape. In calculating drift motions, the following models are required:a fluid model which calculates water levels and flow velocity and a drift model whichcalculates drift motions.
• Regarding the fluid model, we used the Python programming language to develop
a numerical model based on Navier–Stokes equations, considering the ease of theconnection with the following drift model.
• Regarding the drift model, we used the Pybullet, which was the Python version of thephysical engine library “bullet” and the open-source library using a zlib license, fortranslation and rotation of objects as well as collision, for each time step. Pybullet can
express arbitrarily shaped objects by combining basic shapes including spherical, box
and columnar shapes or by feeding .obj files, which is a data format for expressing 3D
objects. Also, many physical engines containing Pybullet can perform high-speed calculation of 3D physical motions, and so they are used for physical calculation in games.
In this drift model, we used fluid force calculated using water levels and flow velocity
obtained from the fluid model and calculate the motion of drift objects at each time.
• In the future, we will validate this drift model by comparing the existing experimental results. Regarding the physical engine used in the drift model, real-time performance wasshown to be more important than calculation accuracy. Therefore, a quantitative assessment of the reproducibility of actual phenomena is required. In addition, we will study
the following: improving
the fluid force evaluaColumns on landtion method for the drift
model; improving theDrift objects: Columns
interaction method of thefluid model and the drift
Drift objects: Vehicles
model; comparing thesemodels with existingmodels; and evaluating
Drift objects: Rectangular solids
debris dam and accumulation in inundation areas
and on collision of debris
with land structures.
Drift objects expressed by combining various basic shapes

Corrosion speed (μA/cm2)

Alkaline environment: dry/humid cycling using saturated
calcium hydroxide aqueous solution

Softening

Marine plate
Note: Alteration of clay minerals, which constitutes
decollement zones, is thought to finish in 100 years.
Accretionary prism
Decollement zone

Marineplate

Results of plate subduction simulations(Left: Excess gap water distribution, Right: Stress-strain relationships at each depth (3 points)

8. Investigation of impact mitigation at the time of collision by applying exterior claddings to underwater robots• Although underwater robots, including inspection ROVs for maintenance purposes, arebeing researched and developed as effective tools, they are basically designed not tocollide to objects. However, in the case of unpredictable disturbance including wave turbulence under piers and nearExterior cladding/collision velocity
structures and ship waves, underwater robots are difficult
Cladded 0.5m/s
to manipulate, and so they might collide with structures andUncladded 0.6m/s
be damaged. This risk prevents their wider use.
• In this study, we cladded the exterior of hovering-type underwater robots. We aimed to mitigate the maximum velocity of these robots accelerated by collision to enable themto continue to operate without breaking. With this goal, weinvestigated the impact mitigating effects of the cladding.
• We cladded underwater robots with several exterior clad- Time variation difference of acceleration
dings including aluminum frames, measured the accelera- velocity (a) which occurs upon collision between cladded robots and uncladded robots
tion velocity acting on the robot bodies when they collided
with concrete walls and steel pipes, and evaluated thesemeasurements quantitatively.
• We aimed to reduce the maximum acceleration velocity
which occurs during collision by lengthening the time fromcollision to stopping, and proposed exterior claddings including a cladding shaped so as to make the robots’ bodies rotate
upon collision. In addition, the combined use of springs anddampers further reduced the maximum acceleration velocity. Collision experiments in which an under• We are going to investigate the effects on collided struc- water robot is collided with a concrete walltures and efficient operation methods.
PARI Annual Report 2018 18

Published Research Papers
Number of Peer-reviewed Papers in FY 2017
Number of papers in Japanese

Number of papers in non-Japanese languages

Total

Rate of papers in non-Japanese language

75(64)

48(12)

123(76)

39.0%(15.8%)*The above numbers contain proceedings that only reviewed the abstract.(Numbers in parentheses indicate the number of journals.)

Papers Published in PARI Reports in FY 2017

Published Research Papers

No.

Title

56-2

Proposal of Modeling of Circular Steel Tube for Seismic Performance Evaluation

56-3-1

Author(s)LanguageMonth/Year

Yousuke OHYA, Yoshio SHIOZAKI, Eiji KOHAMA,
Yuichiro KAWABATA

Japanese

June 2017

Lateral Resistance of Coupled Piles with Its Intermediate Soil Stabilized by Cement
Treating Method

Satoshi MATSUMURA, Takanobu MATSUBARA,
Naruhiko FUJII, Takaaki MIZUTANI,
Yoshiyuki MORIKAWA, Makoto SATO

Japanese

September 201756-3-2

Evaluation of Deformation Process of Granular Materials Based on Image Processing and Development of Numerical Simulation Method

Daiki TAKANOJapanese

September 201756-3-3

Numerical Analysis and Model Testing on a Method for Evaluation of Coastal
Parapet Levees’ Seismic Coefficients for Level-1 Earthquakes

Eiji KOHAMA, Hirofumi FUKAWA

Japanese

September 201757-1-1

Rupture Process of the Foreshock and Main Shock of the 2016 Kumamoto Earthquake and Simplified Source Models to Explain Damaging Ground Motions

Atsushi NOZU, Yosuke NAGASAKA

Japanese

March 201857-1-2

Technological Development of Sheet-pile Quaywall Reinforced by Geogrids

Hidenori TAKAHASHI, Yoshiyuki MORIKAWA,
Takaaki MIZUTANI, Katsuya IKENO,
Tomohiro TANAKA, Suguru MIZUTANI,
Toshiyasu MIYOSHI, Kentaro HAYASHIJapanese

March 2018

LanguageMonth/Year

Note: 56-4 is not available, and is not published.

Papers Published in PARI Technical Notes in FY 2017
No.

Title

Author(s)No.1333

Annual Report on Nationwide Ocean Wave Information Network for Ports andHarbours (NOWPHAS 2015)

Koji KAWAGUCHI, Satoshi SAKURABA,
Takashi FUJIKI, Hitoshi TAMURA

Japanese

June 2017

No.1334

Field measurement and Flume Experiment Studies on Sedimentation in River
Mouth Port, a Case Study in the Port of Niigata

Yasuyuki NAKAGAWA, Noriko TAKASHIMA,
Takumi SHINOZAWA

Japanese

June 2017

No.1336

Practical Approach to Preventive Maintenance of Port Steel Structure

Ema KATO, Nozomu SOMEYA, Yuichiro KAWABATA,
Hiroto TADO, Toru YAMAJI, Nobuhito NAKATANIJapanese

September 2017

No.1337

Generation and Characteristics of Multi-directional Waves in Shallow Water- For Distributed Directional Spectra along Linear Boundary in Constant Depth -Katsuya HIRAYAMA, Yasuhiro AIDA,
Akinori NAKAMURA

Japanese

September 2017

No.1338

Application of Modeling of Circular Steel Tube Considering Diameter-to-Thickness
Ratio to Various Port Facilities

Yousuke OHYA, Yoshio SHIOZAKI,
Eiji KOHAMA, Yuichiro KAWABATA

Japanese

December 2017

No.1339

Study on Chloride Ion Diffusion Property of Concrete Based on Long-Term Exposure Test and Investigation to Actual Structure

Kazuhide YONAMINE, Toru YAMAJI, Ema KATO,
Yuichiro KAWABATA

Japanese

March 2018

No.1340

Proposal of Regression Equations for Displacement Tonnage of Ships

Haruo YONEYAMA

Japanese

March 2018

No.1341

Study on Tractive Forces of Ships Acting on Mooring Posts and Bollards

Haruo YONEYAMA

Japanese

March 2018

Note: No. 1335 is being re-edited; the timing of publication is unknown.

19 PARI Annual Report 2018

PARI Annual Report 2018

Public Relations
Annual Report, Technical Journals,
and Website

Lectures for the General Public
Port and Airport Technology Lecture
Aiming to present and disseminate the achievements of investigations, research, and technical developments carried out
at PARI, we held a Port and Airport Technology Lecture in Tokyoon December 21, 2017 in cooperation with the National Institutefor Land and Infrastructure Management, which was attended
by approximately 250 participants.
Port and Airport Technology Special Lecture in Region
Aiming to widely provide information on the research activities and achievements of PARI and collect information such as
research needs in each region of Japan, we held 4 lecture meetings throughout Japan in cooperation with the National Institutefor Land and Infrastructure Management, the Regional Development Bureau, and others, gathering approx. 650 participants.
Port and Airport Research Symposium
We held the Port and Airport Research Symposium in cooperation with the National Institute for Land and InfrastructureManagement in Yokosuka City on January 12, 2018, which wasattended by more than 100 people.

Open House
Open House
Our Open House (Saturday, July 22, 2017) held a variety ofdemonstration experiments, including “Let’s feel the power ofa giant tsunami!”, hands-on events including “Let’s touch creatures in tidal flats!”, and exhibitions including “Let’s see a jumbo
jet tire!”. 1,085 people visited PARI that day.

Other Outreach Activities
Cooperation with “Yokosuka Children’s University for Disaster Prevention”
We helped run the “Yokosuka Children’s University for Disaster Prevention” event, which is a summer disaster-prevention
initiative to educate fifth-grade elementary schoolchildren living in Yokosuka City. Two groups of children (37 in total) werebrought in and we ran hands-on workshops using models andother tools.

Public Relations

The Annual Report 2017 (Japanese version) and the PARI
Annual Report 2017 (English version), which summarized theactivities in FY 2016, were produced as a record of achievements, and were distributed to the parties concerned and published on PARI’s website.
Regarding the technical journal PARI, we selected special articles for each study theme for every
issue to introduce utilization situations of study results and PARI’s
experiment and on-site observation
facilities. Approximately 1,800 copies of the PARI Technical Journal
were distributed to 1,700 places.
On PARI’s website, we provided
various information on events andnews including PARI’s summarized
information, achievements, facilities, symposiums on a real time basis; we got approximately 250,000
The PARI Technical Journal
accesses in this fiscal year.

Other Facility Tours
Other than the Open House, we held 91 facility tours, with
1,393 visitors. We introduced PARI facilities and PARI-associated research to visitors from private companies, the government, municipalities, and educational institutions to broaden
understanding of PARI’s activities and the social importance of
researchers. We also carried out activities to increase understanding of disaster prevention, such as providing various information on earthquakes and tsunamis.

Cooperation with Super Science High school (SSH) Projects
For first-year students from Kanagawa Prefectural Yokosuka
High School and second-year students from Miyagi Prefectural
Sendai Daiichi High School, both of which are SSHs designatedby the Ministry of Education, Culture, Sports, Science and Technology, we explained our studies and organized tours to PARI’sfacilities to enhance students’ interest in science and math.
Exhibition at Tokyo-wan Daikanshasai 2017 [Tokyo-Bay
Thanksgiving Day 2017]
In October 2017, we set up an exhibition booth at Tokyo-wan
Daikanshasai 2017, which was held at Yokohama Red Brick
Warehouse and its surroundings. There, we promoted PARI’s
activities to many visitors including families with children.

Tokyo-wan Daikanshasai 2017 [Tokyo-Bay Thanksgiving Day 2017]Media Appearances
We distributed information via media outlets, including experimental films explaining the dangers of tsunamis and other materials broadcast on news shows and other programs of Japanese
TV stations. The technical journal Monthly AIRLINE introduced
our research on airport pavement. In addition, articles on various activities of PARI appeared in newspapers, technical journals, and other printed media, a total of 47 times.

Summer Open House
Secrets of airport pavement, Monthly AIRLINE(September 2017 issue)

PARI Annual Report 2018 20

Outstanding Research Activities
Awards for Papers and Others in FY 2017
Name

Award

Institution

Date

The Ministry of
Education, Culture,
Sports, Science andTechnology

April 19, 2017

Remarks

Outstanding Research Activities

1

Hidenori TAKAHASHI

Head, Soil Stabilization GroupThe Commendation for
Science and Technology
by the Minister of
Education,
Culture, Sports, Scienceand Technology(The Young Scientists’Prize)

2

Masayuki BANNO

Senior researcher, Coastal and Estuarine
Sediment Dynamics Group

The Maeda Engineering
Foundation
Yamada Kazuie Award

The Maeda
Engineering
Foundation

June 2, 2017

Shoreline Response on
Multi-time Scales and Future
Shoreline Projection

3

Yutaka TANAKA

Researcher, Structural Mechanics Group

Japan Society of Civil
Engineers
The Yoshida Aword,
Encouraging PrizeJapan Society of Civil
Engineers

June 9, 2017

Development of Spatial
Distribution Model for
Deterioration Factors in
Marine Concrete Structureswith Spatial Statistics

4

Satoshi MATSUMURA

Researcher, Foundations Group

Japanese GeotechnicalSociety, Research
Encouragement Award

Japanese
Geotechnical Society

June 9, 2017

5

Hidenori TAKAHASHI
Shinji SASSA
Yoshiyuki MORIKAWA

Head, Soil Stabilization Group
Head, Soil Dynamics Group
Director, Geotechnical Engineering
Department

Japanese GeotechnicalSociety, Technological
Development Award

Japanese
Geotechnical Society

June 9, 2017

6

Shinji SASSA

Head, Soil Dynamics Group

Japan Society for the
Promotion of Science,
Examination Committee
Award

Japan Society for the
Promotion of Science

August 4,
2017

7

Naruhiko FUJII

Member, Soil Stabilization Group

Japanese GeotechnicalSociety, Excellent
Presentation Award

Japanese
Geotechnical Society

August 27,
2017

Strength property of lime
treated soil cured for thirty
seven years

8

Yuichiro KAWABATA

Senior Researcher, Structural Mechanics
Group

The 17th JSMS
Symposium on Concrete
Structure Scenarios,
Distinguished Paper
Award

The Society ofMaterials Science,Japan

October 13,
2017

Modeling of ASR Expansion
Behaviors of Concretes
Tested by Accelerated
Concrete Prism Test with
Alkali-wrapping

9

Tomohiro TAKAGAWA

Head, Tsunami and Storm Surge Group

Hydrographic Technology,
Encouragement Award

Japan Hydrographic
Association

February 27,
2018

Development of an Ensemble
Tsunami Forecasting Method
Based on Offshore Tsunami
Data

21 PARI Annual Report 2018

PARI Annual Report 2018

PARI Events
Active Commitment in International Meetings,
Workshops, and Other Projects
In December 2015, the United Nations General Assembly officiallydesignated November 5th, which has already been designated as
Tsunami Prevention Day in Japan, as World Tsunami Awareness Day.
In response, we established the Hamaguchi Award (Minister of Land,
Infrastructure, Transport and Tourism Award), which rewards persons
who have made remarkable contributions in the field of coastal disasterprevention technology including tsunami disasters. In November 2017,
the award was given to the following two persons and one group: Philip
Li-Fan Liu, vice president and distinguished professor at the National
University of Singapore and professor emeritus at Cornell University;
Julio Kuroiwa, professor emeritus at National University of Engineering, Peru and director and general manager of Disaster Risk Reduction
Peru International SAC; Kuroshio town (Hata district, Kochi).

Promotion of Administrative Support
Dispatching of Researchers to Disaster Sites
On April 14, 2017, a sediment collapse accident caused tremendous damage at a waste disposal site in Colombo, Sri Lanka. PARI
dispatched two researchers as members of an expert team of the Japan
Disaster Relief Team to help investigate the cause, prevent secondary
disasters, speed up restoration, and other initiatives.
Strengthening Collaboration in Dispatching the Technical
Emergency Control ForceOn March 30, 2018, we signed a cooperation agreement to strengthen various collaboration initiatives with the National Institute for Landand Infrastructure Management of the Ministry of Land, Infrastructure
and Transport (Yokosuka) in dispatching the Technical Emergency Control Force (TEC-FORCE).
PARI Events

A prize awarding ceremony and commemoration lecture of the
Hamaguchi Award (November 1, 2017, Tokyo)

In September 2017, we held the “2017 Japan-Italy Technology Exchange Workshop Regarding Coastal Disaster Prevention” in Venice,
Italy, where we actively exchanged opinions on countermeasuresagainst tsunami and storm surges.
Also, in November 2017 in Seoul, South Korea, we held the KIOSTPPA-PARI Workshop in collaboration with the Korean Institute of Ocean
Science and Technology (KIOST) and the Philippine Ports Authority(PPA). In the workshop, we exchanged opinions on studies on grounds
and earthquakes and deepened our relationships.

Broad Research Exchange with Japanese and
Non-Japanese Research Institutes
To improve the quality and efficiency of research, we actively collaborated on research with domestic and overseas research institutions andsigned a total of 35 research cooperation agreements with 9 Japanese and26 overseas institutions as of FY 2017. In FY2017, we renewed researchcooperation agreement with the Swedish Geotechnical Institute (SGI).
Also, to facilitate emergency disaster countermeasures and smooth
activities, we signed a cooperation agreement with the National Institutefor Land and Infrastructure Management of the Ministry of Land, Infrastructure and Transport on March 30, 2018.

Conclusion of Education and Research
Collaboration Agreements
We signed agreements with national, public and private universities.
Under these agreements, PARI researchers serve as grad-school professors or take other positions at the universities. Under the graduate
school linking system, in which postgraduate students receive instructions at research institutions, we concluded collaboration agreementswith 11 universities including the Tokyo Institute of Technology, Nagoya
University, and Nagaoka University of Technology. In FY 2017, we dispatched 10 researchers as lecturers. We also dispatched a total of two
researchers to universities which are not under the graduate school
linking system, including Tsukuba University.

Concluded a collaboration agreement with the National Institute forLand and Infrastructure Management (March 30, 2018)

Dispatching of Researchers to Various Technical Committees
We dispatched a total of 55 researchers to various technical committees organized by governments and other organizations to solve
technical issues concerning the execution of port, coastal, and airport
public works by national and municipal governments and local administrations. Including technical committees on improving ports, coasts andairports established by various institutions, a total of 360 researchers
were dispatched by PARI, and actively tackled technical issues facedby governments and other organizations.
Dispatching of Lecturers to Training Courses for Domestic Engineers
Training courses for national and other public service engineers areheld by the National Institute for Land and Infrastructure Management.
We actively participate from the planning stage and have dispatched atotal of 23 researchers to 2 training courses as lecturers.
Providing Operational Support for Technical Standards for Ports,
Airports, etc.
Regarding technical standards for port facilities, our researchers
took part in technical committees set up by the Ports and Harbours Bureau of the Ministry of Land, Infrastructure, Transport and Tourism. Our
researchers also gave lectures at the National Institute for Land andInfrastructure Management, conferences, and seminars organized byother relevant organizations, and contributed to the spread of technicalstandards. Regarding airport facilities, our researchers participated invarious investigative commissions in preparation for the smooth introduction and operation of technical standards for airport civil engineering
facilities.
Support for Evaluation of New Technologies
In response to a request of the Ministry of Land, Infrastructure, Transport and Tourism (including regional development bureaus), PARI offered technical support by dispatching researchers to the New Technology Utilization Evaluation Conference established by each organizationfor evaluating the practicality and applicability of the technologies to beregistered in the New Technology Information System (NETIS) in orderto promote the application of useful new technologies.

PARI Annual Report 2018 22

July 2018

−Creating Technologies that Contribute to the World−

National Institute of Maritime, Port and Aviation Technology

Port and Airport Research Institute3-1-1 Nagase, Yokosuka, Kanagawa 239-0826, JAPANTEL +81-46-844-5040 FAX +81-46-844-5072 URL http://www.pari.go.jp