Proceedings of the International Symposium on Engineering Lessons Learned fromthe 2011 Great East Japan Earthquake, March 1-4, 2012, Tokyo, Japan

BUILDING DAMAGE BY THE 2011 TOHOKU JAPAN
EARTHQUAKE AND COPING ACTIVITIES BY NILIM
AND BRI COLLABORATED WITH THE
ADMINISTRATION
Isao NISHIYAMA1, Izuru OKAWA2, Hiroshi FUKUYAMA3 and Yasuo OKUDA4
1

Director, Building Department, National Institute for Land & Infrastructure management (NILIM),
Ministry of Land , Infrastructure, Transport & Tourism (MLIT), Tsukuba, Japan,
nishiyama-i92ta@nilim.go.jp
2
Senior Research Fellow, Department of Structural Engineering, Building Research Institute (BRI),
Tsukuba, Japan, okawa@kenken.go.jp
3
Chief Research Engineer, Department of Structural Engineering, BRI, Tsukuba, Japan,
fukuyama@kenken.go.jp
4
Chief Research Engineer, Department of Structural Engineering, BRI, Tsukuba, Japan,
y_okuda@kenken.go.jp

ABSTRACT: This paper presents the outlines of the strong motions recorded in andaround the buildings by the BRI Strong Motion Network, the motion induced building
and residential land damage and the tsunami induced building damage by the 2011
Tohoku Japan earthquake. On-going coping activities in order to establish necessary
technical standards collaborated with the administration are also introduced.
Key Words: 2011 Tohoku Japan earthquake, strong motion in and around buildings,
earthquake and tsunami damage, buildings and residential land, coping
activities related with building technical standards

INTRODUCTION
The 2011 off the Pacific coast of Tohoku earthquake (Tohoku Japan earthquake) of moment magnitude(Mw) 9.0 occurred at 14:46 JST on March 11, 2011 and generated large ground motion and gigantic
tsunami in Tohoku and Kanto areas of the northeastern part of Japan together with long-period groundmotion in Osaka city. This was a thrust earthquake occurring at the boundary between the North
American and Pacific plates. This earthquake is the greatest in Japanese recorded history and thefourth largest in the world since 1900 (U.S. Geological Survey Website). As of 9 December 2011,
people death reached 15,841 and totally collapsed houses reached 126,280 according to the Japanese
National Policy Agency.
The hypocentral region is widely located off the coast of the prefectures of Iwate, Miyagi,
Fukushima and Ibaraki with approximately 450km in length in the NS direction and 150km in width in504

the EW direction and the distance from these prefectures to the fault plane is almost the same, thus theplaces with the seismic intensity of 6- or more according to the Japan Meteorological Agency widely
spread in these prefectures which resulted in damages of many buildings and residential land.
Simultaneously generated tsunami attacked the coast lines of Tohoku and Kanto areas a little late
producing devastating damages.
The National Institute for Land & Infrastructure Management (NILIM) and the Building ResearchInstitute (BRI) collaborated in the process of the recorded strong motions in and around instrumented
buildings and also in the reconnaissance study of buildings and residential land damaged by theearthquake and the tsunami. In this paper, the outline of the collaborated work is presented first andthen the state of the on-going coping activities on selected issues in order to establish necessary
technical standards. The content of this paper is based on the research and reconnaissance reports(NILIM and BRI 2011a, 2011b), and is mostly taken from the paper by the authors (Nishiyama et al.
2011).

RECORDED GROUND AND BUILDING MOTIONSThe strong motion network (BRI Strong Motion Network Website) covers buildings in major cities
across Japan. When the earthquake occurred, 58 strong motion instruments started up from Hokkaido
to Kansai areas. Among them, 31 buildings including three seismically isolated buildings suffered ashaking with the seismic intensity of 5- or more.
Strong motion records of damaged buildings
At least 4 buildings suffered severe earthquake motions with some damage. One example of thedamaged buildings is the 9-story steel reinforced concrete school building of the Human
Environmental Course, Tohoku University, Sendai city. This building has a long history of recordingof strong motions. Among them, strong motion records on the ninth floor that were obtained during the1978 Miyagi-Ken-Oki earthquake are well known to have exceeded a maximum acceleration of morethan 1000 cm/s2.
During the earthquake, multi-story shear walls of the building suffered flexural failure with otherdamage. Photo 1 and Fig. 1 show the appearance of the building and the records of the strong motion.
The fundamental natural periods of the building calculated every 10 seconds (Kashima and Kitagawa
2005) increased from 0.6 seconds to 1.5 seconds during the earthquake, which clearly shows andagrees with the building damage.
Acc (cm/s2)

1000

Acc (cm/s2)

−1000
1000

Disp (cm)(b) Acc. in Long. Dir.

09F(Long.)
01F(Long.)(c) Bldg. Disp. in Trans. Dir.

0

−40
40
Disp (cm)

09F(Trans.)
01F(Trans.)

0

−1000
40

(d) Bldg. Disp. in Long. Dir.

0

−40
2.0
T (s)

(a) Acc. in Trans. Dir.

0(e) Transition of natural periods

1.5
1.0
Trans

Long.

0.5
0

Photo 1 Building of Tohoku University

50

100
Time (s)150

Fig. 1 Records of strong motion

505

200

Long-period earthquake ground motions in Osaka Bay

Disp. (cm)During the earthquake, long-period earthquake ground motions were observed in Tokyo, Osaka andother large cities. One example is the 55-story steel office building on the coast of Osaka Bay that is
770 km away from the hypocenter. Photo 2 and Fig. 2 show the appearance of the building and therecords of the absolute displacement waveforms. The absolute displacements in the SW-NE and in the
NW-SE directions on the 1st floor was less than 10 cm, but the 52nd floor in the building suffered alarge motion with a zero-to-peak amplitude of more than 130 cm. The pseudo velocity response
spectra for the 1st floor records (Fig. 3) show clear peak at about 7 second period resulted in large
earthquake responses at the top due to a resonance phenomenon.
200 Displacement

01F SW-NE (peak:- 9.1 cm)

0

Disp. (cm)

-200
200

01F NW-SE (peak: 7.8 cm)

0

Disp. (cm)

-200
200

52F SW-NE (peak: 137.1 cm)

0

Disp. (cm)

-200
200

52F NW-SE (peak:- 83.7 cm)

0

Disp. (cm)

-200
200

52F-01F SW-NE (peak:- 138.2 cm)

0

Disp. (cm)

-200
200

52F-01F NW-SE (peak: 84.8 cm)

0

-200
0

100

200

300

400

500

600

700

Time (s)Photo 2 55-story steel office building(Osaka Bay)

Fig. 2 Records of strong motion

10

10

00

0

100 Pseudo Vel. Resp. Spectrum (h=5%)

10

10
10

5

1(
cm
/s/
s)

Pseudo Velocity Response (cm/s)

50

1

1

)
m

1
0.

(c
01
0.

0.5
0

0.1

0.5

1
Period (sec)

SW-NE
NW-SE
5

10

Fig. 3 Pseudo velocity response spectra with damping ratio of 5%

BUILDING AND RESIDENTIAL LAND DAMAGE BY EARTHQUAKE MOTION
The earthquake brought about building damage in a wide area of various prefectures on the Pacificcoast in eastern Japan such as Iwate, Miyagi, Fukushima, Ibaraki and Chiba, and also brought about
heavy liquefaction at the catchment basin area of Tonegawa River and the reclaimed ground on Tokyo506

Bay, thus NILIM and BRI team selected the locations of the reconnaissance study as shown in Fig. 4
with the exception of the area near the Fukushima Daiichi Nuclear Power Station.

Fig. 4 Locations of field surveyed cities and towns
Building damage by earthquake motion
Wood houses
Most of the patterns of the damages to the wood houses by the earthquake were observed in past
destructive earthquakes. They are the inclination and/or collapsed of the 1st story of wood houses withstore as shown in Fig. 5 and Fig. 6 and the fallen down of the finishing due to structural
bio-deterioration shown in Fig. 7. Collapse of the 2nd story shown in Fig. 8 was quite unusual.
Falling of roof tile is observed everywhere at the surveyed locations, but the damage in Fukushima
and Ibaraki prefectures seemed more serious than that in Miyagi prefecture where large earthquakes
struck frequently.

Fig. 5 Inclination of 1st story

Fig. 6 Collapse of 1st story507

Fig. 7 Fallen down of finishing (bio-deterioration)

Fig. 8 Collapse of 2nd story

Steel buildings
Steel gymnasiums are surveyed extensively in Ibaraki prefecture, as the structural system of them issimilar to that of factories and warehouses. Most of the patterns of the damages were observed in pastearthquakes, which are the rupture of braces at the joint as shown in Fig. 9 and the rupture of roof
braces in Fig. 10. The spalling of concrete at the joint of the steel roof structure and the reinforced
concrete column as shown in Fig. 11 and the buckling of latticed column in Fig. 12 were also observed.
The dropping of ceiling was observed at many gymnasiums (Fig. 13) which could not be used for
emergency evacuation sites.

Fig. 9 Rupture of brace joint

Fig. 10 Rupture of roof braces

Fig. 12 Buckling of latticed column

Fig. 11 Spalling of concrete at joint

Fig. 13 Dropping of ceiling

Reinforced concrete buildings
Almost all of the damages of reinforced concrete buildings in the earthquake were observed in past
destructive earthquakes. For example, they are the story collapse in the soft 1st story (Fig. 14) and/or
mid-story (Fig. 15) of buildings due to shear failure of columns (Fig. 16), and so on. The nonstructural
walls adjacent to the door of residential buildings suffered damage quite frequently as shown in Fig.
17. The retrofitted buildings behaved well in general with some exception as shown in Fig. 18.

508

Fig. 14 Collapse of soft 1st story

Fig. 16 Shear failure of column

Fig. 15 Collapse of mid-story

Fig. 17 Nonstructural wall failure

Fig. 18 Damage of retrofitting

Seismically isolated buildings
Sixteen seismically isolated buildings in Miyagi prefecture and one in Yamagata prefecture weresurveyed in which three buildings were instrumented and recorded strong motions. All of them
performed structurally very well (Fig. 19) which was also clarified by the recorded motions. The steel
dampers absorbed earthquake energy by the plastic deformation (Fig. 20). However, the lead dampers
suffered cracks due to many cycles of small amplitude of reversed deformation as shown in Fig. 21.
Damage to the expansion joints (Fig. 22) was seen quite frequently which should be improved verysoon.

Fig. 19 Seismically isolated building performed wellFig. 21 Lead damper cracked

Fig. 20 Yielded steel damper

Fig. 22 Expansion joint deformation

509

Residential land
In the catchment area of Tonegawa River and the coastal zone of Tokyo Bay, extensive damage suchas sand boiling or ground transformation associated with liquefaction was confirmed. Highly tiltedbuildings were seen, but visual cracks or fissures on the foundations investigated were not observed asshown in Fig. 23.
In Sendai city, the ground transformation by sliding of the housing site embankment was observed
as shown in Fig. 24, just like the one under the 1978 Miyagi-Ken-Oki earthquake.

Fig. 23 Tilted house by liquefaction

Fig. 24 Ground transformation by sliding

Building damage by tsunami
The coastal area along Aomori prefecture to Miyagi prefecture shown in Fig. 4, where northern part is
ria coast and southern one is coastal plain, was surveyed. First, the building damage by tsunami wasclassified into several damage patterns from the general reconnaissance survey. Next, about 100
buildings are carefully selected and studied in details such as on the dimension of the structure of thebuilding, the maximum inundation depth at the building from the tsunami traces, damages of thebuilding and so on.
Damage patterns
From the general survey on the reinforced concrete buildings, steel buildings and wood houses whichsuffered tsunami induced damage, the following damage patterns are obtained.
Movement or complete washed away was observed especially in wood houses and steel buildings
as shown in Fig. 25. Overturning with the effect of buoyancy was observed mainly in reinforced
concrete buildings and exceptionally in steel building as shown in Fig. 26. Tilting by scouring wasseen as shown in Fig. 27. Story collapse, out-of-plane deformation of wall and washed out of
claddings shown in Fig. 28 are due to horizontal force by tsunami. Figure 29 shows the effect of debris
impact, and Fig. 30 shows several survived wood houses by the shading effect of the tsunami front
building.

Fig. 25 Movement and complete washed away (left: wood house, right: steel building)510

Fig. 26 Overturning(left: reinforced concrete building, right: steel building)Fig. 27 Tilting by scouring

Fig. 28 Story collapse of 1st story (left), out-of-plane wall deformation (middle)
and washed out of claddings (right)

Fig. 29 Debris impact

Fig. 30 Shading effect by front building

STATE OF THE ON-GOING COPING ACTIVITIESFrom the study and survey of the building damage and so on explained above, the following issues are
obtained to be counter-measured administratively: establishing and/or modifying the related building
technical standards.
 Effect of long-period earthquake ground motion on the buildings with long natural periods
should be considered Fallen down of ceilings especially in gymnasium type of buildings should becounter-measured
 Subsidence and inclination of residential land of detached houses by liquefaction should becounter-measured
 Design guidelines for tsunami evacuation buildings against tsunami force should beestablishedConcrete research on each issue is explained as follows. The research results are planned to be
implemented in the building technical standards by the administration taking into account the neutral
expert opinions by the Building Structural Codes Committee (Fig. 31) established in NILIM.

511

Building Structural Codes Committee
Chaired by Tetsuo Kubo, Tokyo University
Field Survey on the Earthquake on April 21 and 22
First meeting was on June 8, second on August 18
WG on Long‐period earthquake
ground motion
First meeting was on July 20
Secretariat for supporting
Committee and WG
ＴＧ on Building Structural Codes andStandards in general
First meeting on July 26

Draft of
Building
Structural
Codes

Public comments on Tentative
Plan of countermeasures forlong‐period motion
Collection of information byusing grant‐in‐aid formaintenance and promotion ofbuilding standards
42.Effect of long‐period
motion on super high‐risebuildings
21. Needs and seeds
collection

Publiccomments or
proposal ofbuilding
structural
codes fromprivateFig. 31 Building Structural Codes Committee
Long-period earthquake ground motion
A social concern on the long-period earthquake ground motions by mega-earthquakes at the
subduction zone near ocean trench is raised, and the prediction maps are announced based on detailed
calculation (Headquarter for Earthquake Prediction Website 2009, 2012). However, the prediction justincludes the components of motions with the period longer than 2.0 second and so the higher mode
response of the buildings cannot necessarily be represented. Moreover, the prediction could not predict
the occurrence of the earthquake and does not include the combined mega-earthquakes such as the
Tonankai-Nankai earthquake for instance.
NILIM and BRI with the collaboration of the administration adopted much practical empiricalprediction method (Okawa, et al. 2010) based on the observations at about 1,600 recording stations
across Japan, the result of which had been released in December 2010 and received several hundredsof public comments. From the earthquake, numbers of high quality record data base became available
and additional validation studies on the empirical prediction method is now undergoing. Figure 32
shows the predicted motion for Nankai earthquake compared with other researches results.
h=5%

Mw8.2
Mw8.4

Fig. 32 Source model (left), predicted velocity response spectrum at Osaka by other researchers(middle), and prediction by our empirical prediction method (right) for Nankai earthquake
Fallen down of ceilings
The problem of fallen down of the ceilings which cover large space such as gymnasiums and so on has
been indicated by NILIM and BRI since 2001 Geiyo earthquake, and technical advice to keep
appropriate clearance between ceiling and surrounding structure and to install appropriate amount of
diagonal braces on hanging bolts as shown in Fig. 33 with the collaboration of the administration.
In the earthquake, huge number of large space ceilings fell down and even casualties occurred.
Therefore, extensive detailed survey on fallen down ceilings in the earthquake was initiated, where
151 damaged ceilings are collected and 11 of them were studied in detail. Based on this study with the512previous knowledge, the current qualitative technical advice is under the study to be modified intomuch quantitative one.

Fig. 33 Schematic explanation of current technical advice on details of ceilings
Liquefaction
For wood houses, the structural calculation is released in the Japanese Building Standard Law. Thus,
the liquefaction countermeasures cannot be considered at present in the building construction for thedetached houses. Vast liquefaction damage of residential land in the earthquake can be a reason ofmodification to more strict requirements in the law, but it may be an excessive requirement for theland of lower risk of liquefaction. Therefore, a study was started on the application of the system of
performance indication to such detached houses answering to the social demand in the consumer
protection on liquefaction of residential land.
Considering the usable cost for the performance indication for residential houses, the Swedishweight sounding test method may be the available foundation investigation tool. Currently, possibilityof the classification of the liquefaction risk mainly by the Swedish method together with public
information such as micro ground configuration and ground water level and so on is studied.
TsunamiAs for the design of buildings against tsunami force, the guidelines for tsunami evacuation buildings(Cabinet Office 2005) are the unique technical information at present. These guidelines are establishedas part of the countermeasures for Tonankai-Nankai earthquake provided by the Central Disaster
Management Council. In the guidelines, the tsunami force is considered to be equivalent static waterpressure as shown in Fig. 34 where the static water pressure of 3 times of the inundation depth isconsidered including the tsunami dynamic force. Here, 3 is the coefficient of water depth proposed by
the waterway model test (Asakura, et al. 2000).
About 100 buildings were carefully selected and studied in detail as explained above. First, thehorizontal resistant strength of each building is evaluated whether damaged or not from the surveyed
dimensions. Next, the coefficient of water depth is calculated so that the tsunami horizontal force
estimated considering the observed inundation depth at or around the building as a function of thecoefficient agrees with the calculated building strength. Figure 35 shows the relation of tsunami
inundation depth and the estimated coefficient for the studied buildings. It can be seen that thecoefficient of water depth is about 1.0 and it reduces as the inundation depth increases.
In the tentative guidelines announced from the administration in December 2011, the coefficient ofwater depth was relaxed as 2.0 in case the building was blessed by the shading effect from front
building and/or embankment and further relaxed as 1.5 in case the building located at 500 m or larger
from the coastline and river in addition to shading effect. The effect of the openings of the building is
also taking into account in the tentative guidelines.

513

Equation of Tsunami
Wave Pressure

3h

BuildingshzDesign inundation depth

3ρgh

Equation of Tsunami Wave Pressure: qx=ρ g (3h‐z)
qx: design tsunami wave pressure (kN/m2)
ρ： density of water (t/m3)
g： gravitational acceleration (m/s2)
h： design inundation depth (m)z： height from the ground (0≦z ≦ 3h) (m)Fig. 34 Design tsunami force in the guidelines by the Cabinet Office

Fig. 35 Estimated coefficient of water depth of detailed studied buildings

CONCLUSIONSThe National Institute for Land & Infrastructure Management (NILIM) and the Building ResearchInstitute (BRI) collaborated in the process of the recorded strong motions in and around instrumented
buildings and also in the reconnaissance study of damaged buildings and residential land by theearthquake and the tsunami. In this paper, the outline of the collaborated work is presented first andthen the state of the on-going coping activities on selected issues - long-period earthquake groundmotion, fallen down of ceilings, liquefaction and tsunami - in order to establish necessary technicalstandards.

ACKNOWLEDGMENTS
The authors wish to express their gratitude to the members of NILIM and BRI who served for data
analyses of observed strong motions and site surveys of earthquake and tsunami damage of buildings
and residential land, and to those of the building users/owners who allow site surveys under severe
restoration conditions.
Finally, the authors would like to express our deepest condolences to those who lost their families
and those who are suffering from the disaster.

514

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