●Messages from Departments and Centers of NILIM

Comprehensive Efforts after the Great East Japan
Earthquake
to Reduce Damage by a Comprehensive Interdisciplinary Approach
KISHIDA Hiroyuki (Dr. Eng.)
Executive Director for Research Affairs(Keywords) Large earthquake, reconstruction/recovery, interdisciplinary
1. Introduction
On the same day as the Great East Japan
Earthquake of March 11, 2011, the NILIM began tosend staff to the disaster region to provide
technological support by surveying the state ofdamage and cleanup work on site. Later, the head
office and regional development bureaus of theMinistry of Land, Infrastructure, Transport andTourism (hereafter “MLIT”) provided technicalsupport as needed at each stage, either on site or atstudy meetings, to draw up reconstruction andrecovery plans or to prepare various countermeasures
such as revising necessary technical standards. By
January 27, 2012, the number of personnel, all experts
in their respective disciplines, sent to the disasterregion under TEC-FORCE had reached 142 (372
man-days), as shown in the table.
2. Past efforts
This section introduces the major activities for eachphase which the NILIM has carried out.
(1) Immediately after the disaster
The NILIM provided technological guidance to help
evaluate the serviceability and quickly restore various
social infrastructures which are indispensable for saving
lives and rebuilding them. Regarding roads, it provided
technical
guidance
concerning
serviceability
evaluations and emergency inspections to support theclearing, inspection, and restoration of trunk roads.
Concerning rivers and coasts, it provided technicalguidance by surveying the state of damage andemergency restoration necessary before a flood
discharge. Regarding ports and airports, experts on
tsunami and various kinds of facilities surveyed thedamage to key ports and to Sendai Airport. For sewage
treatment systems, they surveyed the state of damage
and provided technical guidance to ensure publichygiene in the event of sewage overflows, and guidanceon how to respond urgently to the suspension of sewage
treatment plants. In particular, to summarize emergency
proposals until sewage treatment plants have recovered,
the NILIM has provided technical support withemergency restoration methods and simple treatment
methods. Regarding building construction, it has carriedout a number of damage surveys, and regarding erosion
control, it has given technical guidance on inspecting
and evaluating the safety of steep slopes at risk ofcollapse and sediment disasters.
Table 1. Personnel sent to the region under
TEC-FORCE
Specialization

Total number of personnel
dispatched
23 (64 man-days)
5 (15 man-days)
8 (21 man-days)
14 (41 man-days)
3 (8 man-days)

SewersRiversShoreline
Bridges
Dams
Road disaster2 (6 man-days)
prevention
Building structures
38 (99 man-days)
Building fire
6 (17 man-days)
prevention
Airports
3 (16 man-days)
Ports and harbors
15 (44 man-days)
Erosion control
17 (25 man-days)
Earthquake disaster8 (16 man-days)
prevention
Total
142 (372 man-days)* Total of 84 (252 man-days) sent during the month
immediately after the disaster(2) Major past efforts
After emergency activities of this kind, the NILIM
and the bureaus of the MLIT jointly examined thedamage and its causes, then based on the results,
verified the suitability of present technical standards
etc. and considered measures to restore facilities.
Typical activities include verifying serious damage
caused by the tsunami along the coast, and identifying
the scale of the tsunami at coastal locations, thenbased on the results, conducting joint studies withresearchers in various related fields to prepare ahandbook on simulating tsunami inundation. To
encourage use of this handbook to help prepare
restoration countermeasures, the NILIM set up acontact section for consultation by cities, towns, andvillages. The results have also helped to set design
tsunami levels for coastal dikes, which are essential
for restoration and recovery (in cooperation with theMinistry of Agriculture, Fisheries and Forestry, July11). Studies on methods of designing structures inother fields are also being conducted in line with theconcept of setting design tsunami levels. Regarding
building construction for example, the Building
Structure Standards Committee formed by the NILIM

●Messages from Departments and Centers of NILIM
has studied “Countermeasures to Ensure Safety basedon Damage to Buildings, etc.” and has clarified theexternal forces required to study the structure oftsunami evacuation buildings by, for example, findingout how a tsunami
forms a swell-head upon
encountering a building. Standards for improving
non-structural members and measures to handle
long-cycle earthquake motion are also being studied.
In addition to tsunami damage, this earthquake
caused liquefaction resulting in widespread damage.
On reclaimed land in the Kanto region, along Tokyo
Bay and in the interior, all far from the hypocenter, theearthquake caused severe damage to ordinary homes
and other buildings. Meanwhile, public infrastructuresuch as water mains, sewer pipes, and other lifelines
was severely damaged as well as structures, and riverlevees settled and were breached. The NILIM studied
common technical matters for combating liquefaction
at meetings with various experts, and helped them
distribute the findings of their surveys. The results
showed that the FL method, which has long been used
for judging liquefaction, can generally judge theoccurrence of liquefaction caused by an ocean trench
earthquake. Earthquake records obtained during thisrecent earthquake will be used to study and verify
dynamic analysis methods for ground, improve theprecision of estimating ground deformation, and help
rationalize liquefaction countermeasures. All theseissues must be considered when conducting reviews ineach field in future.
To study tsunami and liquefaction countermeasuresand design concepts, the NILIM will use its strengths
as a comprehensive research institute to collectdocuments
andexchange
informationon
countermeasures in related fields, methods of setting
the external force of tsunami, etc.
Technical standards for structures which are revised
or scheduled to be revised reflecting the results ofresearch by the NILIM include, in addition to theabove standards, the Specifications for Highway
Bridges and the Guideline to Earthquake ResistanceCountermeasures for Sewage System Facilities.
New efforts are also needed. Radioactive substances
dispersed by the accident at the Fukushima Daiichi
Nuclear Power plant have severely affected many
sewage treatment systems, particularly in the Tohoku
and Kanto regions. The NILIM is surveying thebehavior of radioactive substances in sewage
treatment processes, and studying the safe handling ofsewage sludge containing radioactive substances.
For information about research in each field andtheir incorporation in major standards, please refer toreports on research trends and achievements in eachfield related to the Great East Japan Earthquake inlater sections.
3. Conclusion
One challenge revealed by the earthquake is, as
pointed out by the Central Disaster Prevention Council,

the need to conduct nationwide studies of the largest
earthquakes and tsunami which occur once every
1,000 years, and to revise preparations for nationwide
disasters including West Japan, by for example,
forming a Cabinet-level committee to study models of
massive earthquakes of the Nankai Trough. TheNILIM, to improve crisis management research toprepare for huge external forces and multiple naturaldisasters, must work on: 1) analyzing historical cases,2) revising methods of building disaster scenarios, 3)
examine robust “hard” (structural) countermeasures,and 4) study the combination of both “hard” and“soft” countermeasures to mitigate disasters, byholding seminars and forming working groups, etc.
within the NILIM. As a comprehensive research bodythat supports the technological policies of the MLIT,
the NILIM will not only provide technical support for
restoration of the affected regions, but will also
support integrated crisis management countermeasures
including both “hard” and “soft” measures throughout
Japan.