BUILDING RESEARCH INSTITUTEThe Great East Japan
Earthquake Damage Report
The Building Research Institute of Japan has conducted an extensive survey of the damage caused tobuildings and homes by seismic motion and tsunami waves during the 2011 Great East Japan Earthquake,and offers this report. (Detailed data including damage due to tsunami: http://www.kenken.go.jp/english/
index.html)
To obtain technicaldata to be used in a review of technical standards in light of theearthquake, after theearthquake struck the
Building ResearchInstitute (BRI) and the
National Institute forLand and InfrastructureManagement (NILIM)
set about the task ofcollecting information
on damages due to seismic movement and thetsunami waves, focusThe tsunami swept away all the wooden and low-rise build- ing primarily on buildings in this coastal area of Onagawa, Miyagi Prefecture,
ing structures.
except for a solitary reinforced concrete building.
The shaking experienced around thet 2:46 p.m. on March 11, country is important information through2011, what is formally known which we can understand the structural
as the “2011 off the Pacific damage caused by the earthquake. To
coast of Tohoku Earthquake” look at this, we will introduce strong mostruck, with an epicenter off the coast of tion seismograms recorded in the disasSanriku. Casualties from the disaster ter-affected regions, which were obtained
stand at 15,839 fatalities and 3,642 miss- through the strong-motion earthquake
ing. Damage to buildings includes observation project conducted by the120,241 buildings completely destroyed, BRI. The epicentral area of this earth189,822 buildings partially destroyed quake was extremely large, and regions
and 598,587 buildings partially damaged experiencing strong motion occurred(announced by the National Police across the widest area ever seen.
While buildings also suffered damAgency as of November 17, 2011).
While the size of the earthquake age, buildings constructed according to
was reported as magnitude 7.9 by the the new earthquake resistance standards
Japan Meteorological Agency immedi- did not suffer major damage. In light of
ately after it struck, on March 13 this lessons learned from earthquake damage
was revised to 9.0 (on the moment mag- due to the 1978 Miyagi earthquake andnitude scale). An earthquake of this size others, Japan strengthened its seismic
was Japan’s largest in recorded history, design standards in accordance with theand the scale of damage it caused was Building Standards Law and related
ordinances from June 1981. These stanalso greater than ever experienced.
The tsunami waves that arrived dards are known as the new earthquake
along the coast shortly after the earth- resistance standards.
quake hit reached far inland over a vast
area from Aomori Prefecture in the Large Epicentral Area
north to Chiba Prefecture in the south,
The earthquake was felt across a wide
resulting in immense damage.

Figure 1: Distribution of slip amounton the fault estimated from tsunami
measurements (Fujii et al:, 2011,
Earth, Planets and Space)

A

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The Japan Journal DECEMBER 2011

area from Hokkaido to western Japan.
As the earthquake occurred along what
is known as a plate boundary, the ruptured epicentral area was large, and theresultant aftershock area is estimated tohave been around 500 km to the northand south, and around 200 km to theeast and west. The seismic rupture
began around the area indicated by thesymbol in Figure 1, and according to
BRI analysis, the largest slip amount of
about 48 meters occurred in the vicinityof the ocean trench where the plateboundary is located. It is also estimatedthat between 10 and 30 meters of slip
amount occurred from off the coast of
Miyagi Prefecture to the southern
Sanriku Coast, approximately ten meters
off the Fukushima coast and roughly
two meters off the coast of Ibaraki
Prefecture. Off the central Sanriku coast,
slip amount of between five and elevenFigure 2: Distribution of seismic
intensity for each region during themain shock

Figure 3: Records obtained from BRIstrong motion observation stations

meters is estimated in some areas.
The symbol in Figure 1 indicates thestarting point of the rupture which represents the beginning of the earthquake.
From this point the rupture widened as
far as off the coast of Iwate Prefecture to
the north and Ibaraki Prefecture to thesouth, resulting in a vast epicentral area.

were felt across almost all of Japan.

Widespread Shaking

The seismic intensity
readings shown in Figure 2
are calculated from groundbased observation records.
Seismic movements vary not
only according to the size ofan earthquake and the distance from the epicenter, butalso due to ground conditions
at the observation point.
To determine whether abuilding is resistant to earthquakes, it is important to determine not only the responseof the building during anearthquake, but the seismic
motions which acted upon

*1 K-NET: A ground-based strong-motion
earthquake observation network installed
across Japan by the National ResearchInstitute for Earth Science and Disaster
Prevention and the system which transmits
strong-motion recording data via the Internet.
*2 Gal: Unit of acceleration (1 gal= 1 cm/s2)

Figure 5: Comparison of observed waveforms (velocity waveforms)
for the same building during the 1978 Earthquake off the Coast of
Miyagi Prefecture (blue) and the 2011 Earthquake off the Pacificcoast of Tohoku (black)
Velocity (cm/s)

June 12, 1978 Off the Coast of
Miyagi Prefecture Earthquake

March 11, 2011 Off the Pacific Coast of Tohoku Earthquake

Time (seconds)

the building at the time. This is easy ifseismic observations are conducted inbuildings. The BRI conducts seismic
observations targeting buildings at approximately seventy locations nationwide with the aim of measuring theearthquake resistance of buildings.

Pseudo Velocity Response(cm/s)

Figure 6: Characteristics of seismic movements
in disaster-affected regions (inside buildings).
The stated level is exceeded at 2 and 3 seconds
into the cycle, but this is not a problematic level.
Damping Ratio: 5%

Akita Prefectural Office B1F
Hachinohe City Hall GL
Iwaki City Hall B1F
Miyako City Hall GL
Niigata City Hall B1F
Sendai Government Office Building B2FDesign Level on Bedrock

Period (seconds)
Figure 7: Seismic motion characteristics at observation stations in the Tokyo metropolitan area
(first floors, basement floors or ground surface)

Pseudo Velocity Response(cm/s)In Japan, the size of earthquake shocks is
expressed in terms of the Japan
Meteorological Agency (JMA) Seismic
Intensity Scale. The largest seismic intensity recorded during the 2011 earthquake
was level 7 at the Tsukidate station in
Kurihara, Miyagi Prefecture. No otherareas recorded level 7 intensity.
However, in terms of peak ground acceleration, which is an alternate indicator of
shaking used by strong motion observation networks operated by other agencies
such as K-NET*1, this measurement surpassed 1,000 Gal*2 at many observation
stations. As Figure 2 shows, the shocks

Figure 4: BRI strong motion observation
stations in the Tokyo metropolitan area

Damping Ratio: 5%

Educational Center, Funabashi City GL
Gyotoku Library, Ichikawa City 01F
Central Government Building No. 6 01F
Sumida Ward Office B1F
37-story High-rise Residential Building, Chuo Ward 01F
Shinagawa International House, Tokyo Universityof Marine Science and Technology
Design Level on Bedrock

Period (seconds)
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BUILDING RESEARCH INSTITUTE
Table 1: Main strong motion records obtained by BRI
CodeStation Name

SND

Sendai Government Office
Bldg. No. 2 (high-rise)

THU

Tohoku University Civil Engineering andArchitecture Bldg.

IJMA

Loc.

175

5.2

B2F*
15F

Max. Acc. (cm/s2)
H1
H2
V
163
259
147
361
346
543

177

5.6

01F*

333

_ (km)

MYK

Miyako City Hall

188

4.8

IWK

Iwaki City Hall

210

5.3

ANX

Building Research Institute

330

5.3

SIT2

Saitama Shintoshin Government
Office Building No.2 Annex (high-rise)

378

4.4

SITA

Saitama Shintoshin
Government Office Building, Public
Welfare Building

378

NMW

National Museum of Western Art(base-isolation)

CGC

330

257

09F

908

728

640

01F
07F
GL*
B1F*
09F
A01*
A89
BFE
8FE
MBC
M8C

138
246
174
175
579
279
142
194
597
203
682

122
197
174
176
449
227
153
191
506
206
585

277
359
240
147
260
248
102
136
344
152
311

B3F*

74

63

42

10FS

119

138

62

27FS

248

503

107

4.5

01F*

90

105

47

382

4.8

GL*
B1FW
01FW
04F

265
100
76
100

194
79
89
77

150
84
87
90

Central Government Office Bldg. No.6
(high-rise)

386

4.4

CG2

Central Government Office Bldg. No.2
(high-rise)

386

4.2

CG3

Central Government Office Bldg. No.3
(base-isolation)

386

4.5

NDLA Annex, National Diet Library

SKS

Sakishima Office, Osaka Prefecture(high-rise)

387

4.5

770

3.0

01F*

90

86

45

20B
19C
B4F*
13F
21F
B2F*
B1F

208
179
75
137
121
104
55

148
133
71
113
131
91
41

173
130
49
72
104
58
62

12F

94

82

104

B8F
B4F
01F*
04F
01F*
18F
38F
52FN
52FS

61
68
76
125
35
41
85
127
129

88
101
104
192
33
38
57
88
85

53
56
84
94
80
61
18
13
12

Note: _: epicentral distance; IJMA : instrumental seismic intensity (calculated from records of acceleration of
three components according to JMA method using asterisked sensor); Installation azimuth: clockwise direction
from North; H1, H2, V: maximum accelerations in horizontal #1 (Azimuth), horizontal #2 (Azimuth + 90°) andvertical directions. A01: Ground surface A89: 89m underground

In Japan, strong-motion earthquake
observations began in 1953. The BRI
has also conducted building observations over a long period that dates backto this time. Figure 3 shows which of thecurrent BRI observation stations recorded measurements during the 2011 earthquake. As shown in Figure 4, the observation stations are more densely
arranged in the Tokyo metropolitan area.
Table 1 shows the instrumental seismic intensity and directional peak acceleration for the main strong motion stations.
In terms of observed values, observation stations such as Sendai Government
24

The Japan Journal DECEMBER 2011

Office Bldg. No. 2 (SND), Tohoku
University (THU) and Iwaki City Hall
(IWK) show high levels. In particular,
the reinforced concrete structure of the
Civil Engineering and Architecture building at Tohoku University was damaged
and has been rendered unusable. At thetime of the 1978 Miyagi earthquake thatstruck in June 1978, acceleration of morethan 1G was recorded on the ninth floorof this building.
Long-lasting Shaking

As mentioned earlier the epicentral area

was large, and since there was a long timefrom the start to end of rupturing at theepicenter, the shocks felt in all regions
continued for longer than ever before.
Table 1 shows the instrumental intensity, directional peak acceleration, etc. ofthe shocks recorded at major observation
stations during the 2011 earthquake.
Of these stations, the Civil
Engineering and Architecture building(ninth floor) at Tohoku University,
which recorded a large velocity response
during the 1978 off the coast of Miyagi
Prefecture earthquake, also obtained alarge recording this time. However,from the comparison of their respective
velocity waveforms shown in Figure 5
we can see that the 2011 earthquake wasmuch longer than the 1978 earthquake.
In Figure 6, we compared the pseudo
velocity response spectra that indicatesthe cyclical size of seismic motions forbuildings in the main disaster-affected
regions of Sendai, Iwaki, Miyako andHachinohe. The observations were recorded at building ground level, basement level or on the ground. For between two and three seconds of thecycle, the observations slightly exceeded
the Building Standards Law design
spectra level for engineering bedrock,but not by such a large margin. In addition, observations in the long-periodareas were not especially large.
Also note that at Miyako City Hall,
the government building was inundated
to the second floor. Since the recording
device for seismological data was on the
top floor of the government building, wewere able to retrieve the data.
Figure 7 shows the pseudo velocity
response spectra indicating the cyclical size of seismic motions for the observational data obtained in buildingsin the major areas of the Tokyo metropolitan area.
Even in the Kanto region, K-NET
and other networks observed extremely
strong shaking at some stations in theprefectures of Ibaraki, Tochigi and Chiba.
However, observation values in theTokyo metropolitan area itself were notthat large.
Long-period Seismic Motion

Based on the size of the 2011 earthquake, strong long-period seismic mo-Photo 1: Mid-story collapse in a low-risebuildingtion was predicted, but in fact, this was
not seen to a great extent in the Tokyo
metropolitan area. In the Osaka Bay
area, however, despite being about
770 km from the epicenter, high-risebuildings resonated at an approximate
7-second cycle due to the long-period
shaking, and in one case a sway of 260
centimeters was recorded near the top ofa building on the fifty-second floor.
Note that even in the Tokyo metropolitan region, more than a little elevatorand non-structural damage in high-risebuildings has been reported.
Damage to Buildings and Homes
Due to Seismic Motion

While the 2011 earthquake was of ascale that Japan has never before experienced, buildings designed according to
the new earthquake resistance standards(earthquake resistance standards introduced since June 1981) are believed tohave suffered little structural damage.
On the other hand, some problems havebecome clear. Among them the fallingof non-structural materials such as ceilings was seen even in buildings designed according to the new earthquake
resistance standards, and many buildings
suffered damage in the form of tilting
due to widespread ground liquefaction.
Investigating the causes and finding solutions to these types of damage will bea major challenge in the future.

seismic intensity scale Figure 8: Location of surveyed cities and towns
was recorded. As a
Tono City
result, BRI confirmed
Miyako City
significant damage in
Yamada Town
Kitakami City
Otsuchi Town
areas such as the cities
Kamaishi City
Hiraizumi Town
of Osaki in Miyagi
Ofunato City
Prefecture andKurihara City
Rikuzentakata City
Sukagawa in
Kesennuma City
Minamisanriku Town
Fukushima Prefecture,
Ishinomaki City
the town of Nasu in
Onagawa Town
Nasu-gun, Tochigi
Higashi Matsushima City
Matsushima Town
Prefecture and the
Shiogama City
Shichigahama Town
cities of Hitachiota
Tagajo City
Sendai City
and Naka in Ibaraki
Natori City
Prefecture. On the
Iwanuma City
Watari Town
other hand, inYamamoto Town
Shiroishi
City
Kurihara, Miyagi
Nasu Town
Fukushima City
Nihonmatsu
City
Prefecture, which reYaita City
Miharu Towncorded level 7 on the Shirosato Town
Koriyama City
Sukagawa City
Kasama City
Shirakawa City
seismic intensity
Hitachiota City
Chikusei City
scale, the damage was
Hitachi City
Shimotsuma City
Naka City
not so great compared
Hitachinaka City
Mito City
Furukawa
City
with the instrumental
Oarai Town
Bando City
Omitama City
seismic intensity that
Joso City
Hokota City
Kashima City
was recorded.
Tsuchiura City
Itako City
Ryugasaki City
The types ofKamisu City
Sakae Town
Surveyed cities and towns
Inashiki City
Urayasu City
damage observed
due to seismic movement of the 2011 earthquake can be motion, this includes roofing tile dambroadly categorized as either “damage age such as falling bricks or tiles, damattributable to shaking due to seismic age to interior materials and exteriormotion” and “damage attributable to walls ( Photo 2 ), tilted buildings andground deformation.”story collapses (Photo 3). These forms
As forms of damage due to seismic of damage are largely consistent withthe damage seen in past earthquakes.
As for damage due to ground deformation, multiple cases of damage tofoundations and wall surfaces associatedwith the breaking up of the ground or retaining walls and the tilting or collapse ofbuildings were observed. In addition,
since we observed many cases of significant damage on residential land built
upon lowland swamp or filled-in ricepaddies, we believe it is possible that the
Photo 2: Fallen parts of exterior walls
soft ground amplified the seismic motion.
Damage to Buildings of Steel Frame
Construction

Damage to Wooden Buildings

BRI conducted a survey of damage towooden buildings in Miyagi, Fukushima,
Tochigi and Ibaraki prefectures, including in the city of Kurihara, Miyagi
Prefecture, where intensity level 7 on the

Photo 3: First-floor story collapse

BRI conducted an exterior survey ofdamage to general buildings of steel
frame construction such as office buildings in Miyagi, Fukushima and Ibaraki
Prefectures. In addition, BRI conducteddamage surveys of structures such as
school gymnasiums designed according
to the old earthquake resistance standards
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BUILDING RESEARCH INSTITUTE

Buckling
Fracture

Photo 4: Damage to exposed column
bases

Photo 5: Buckling of bracing materials
and joint fracture

across a widespread area in Ibaraki
Prefecture where intensity 5-upper to
6-upper shocks were observed.
In the exterior survey damage togeneral buildings of steel frame construction, we observed several cases ofdamage to the bracing structures ofbuildings such as parking lots, such as
buckling of the bracing materials or
damage to the bracing joints. Damage tothe exposed column bases of parking
lots was also observed (Photo 4). In thescope of this survey, no cases of criticaldamage such as fracture of major structural components like columns andbeams were observed.
In the damage survey of school gymnasiums, etc. in Ibaraki Prefecture, we
observed (i) buckling and fracture of vertical braces and fracture of joints (Photo5); (ii) buckling in the diagonal bracingof lattice columns (Photo 6); (iii) damage
to the joints between reinforced concrete
columns and the roof (bearing support
parts); (iv) curvature, buckling and frac-ture of roof horizontal bracing; (v) cracking of column base concrete; and (vi)other damage (overturning of floor strut,etc.). However, the proportion of structures that suffered significant structural
damage such as fractured vertical bracingor joint fractures can be considered low
compared with the results*1 of a similar
survey conducted at the time of the 2004
Mid-Niigata Prefecture Earthquake.

Buckling
Photo 6: Buckling of diagonal bracingof lattice columns (part shown withyellow dotted line)
26

The Japan Journal DECEMBER 2011

Damage to Reinforced Concrete
Buildings, etc.

We conducted a damage survey ofreinforced concrete (RC) buildings
and steel reinforced concrete (SRC)
buildings, mainly in the urban areasof regions where stations recorded
seismic intensities of 6-lower andover in Iwate, Miyagi, Fukushima and
Ibaraki Prefectures.
Considering the large seismic intensities observed in each area, we generally found that structural damage was
not so heavy. However, in areas suchas Wakabayashi Ward in Sendai andthe city of Sukagawa on land that wasonce rice paddies and moats, a relatively higher concentration of structural
damage was seen. Based on this, we
believe it is possible that ground conditions had something to do with thedamage that occurred.
Most of the structural damage seenin this survey was largely consistent withearthquake damage observed in the past.
For instance, major damage such as midfloor collapses in low-rise buildings(Photo 1), first-floor collapses (Photo 7)
of soft first-story piloti structures andcolumn shear failure due to loss of vertical load carrying capacity (Photo 8) also
occurred, but most of the structures

which suffered damage were buildings
designed according to the old earthquake
resistance standards. On the other hand,very few buildings designed according to
the current earthquake resistance standards suffered damage, although in some
SRC buildings, damage such as bucklingin the main reinforcements near baseplates at the bottom of columns, shear
cracks at the beam-column joints or horizontal cracks at the concrete placing
joints were seen. At housing complexesin particular, we also observed manycases where shear failure occurred with
non-structural walls around entrances andveranda-side mullion walls (Photo 9),
and this occurred irrespective of whether
old or current earthquake resistance standards had been adopted.
In the 2011 earthquake, despite thefact that there was relatively less major
structural damage, we did see cases
where public buildings such as city halls
constructed according to the old earthquake resistance standards had suffereddamage to the extent that they could not

Photo 7: Floor collapse on the first floorof a piloti structure

Photo 8: Shear failurePhoto 9: Non-structural shear failure

be used. These buildings are supposed
to function as bases of operation during
an emergency, and the loss of thosefunctions may serve to again highlightthe need for earthquake retrofitting.
Damage to Residential Land andGroundIn the 2011 earthquake, building damage due to ground liquefaction occurred
mainly in the bay area of the Kanto region. In our survey, we observed thewidespread occurrence of damage suchas sand boiling and ground deformation
associated with liquefaction in the alluvial plain area along the Tone river on
the border between Ibaraki and Chiba
Prefectures and in the city of Urayasu,
Chiba Prefecture. Buildings with severe
tilting ( Photo 10) were also seen, but
within the scope of our survey, we did
not observe cracked or damaged foundations from the exterior.
In Miyagi, Fukushima and Tochigi
Prefectures, significant damage (Photo11) associated with sliding of the soil occurred mainly in developed housing
areas (at their periphery in particular). In
some areas we saw that deformation
occurred again on developed land that
had been damaged by past earthquakes.
There was also a case on residential land
which suffered significant damage
where the soil under the foundations had
slid away, but where the foundations
were still holding together.

structural damage such as story collapse,
damage to exterior walls, curtain wall
structures, openings and other nonstructural materials was observed.
We observed extensive damage associated with exterior walls and curtain
wall structures, including the sheddingof exterior tiles from RC walls and thedropping of things like outer wall panels(Photo 12). We observed many buildings
in which the glass from glass openings
had broken. In gymnasiums, interiormaterials had been damaged or had fallen from the interior walls of the arena,and from the interior materials above thestage. The ceilings of gymnasiums built
using a variety of construction techniques were also damaged, with the severity of damage ranging from smallscale damage along the edges to largescale damage where entire ceilings fell
down. At an airport terminal building
where the lobby ceiling had fallen down
(Photo 13), we observed that the layoutof the roof and ground below was uneven and complicated.
As for damage to non-structuralcomponents, those built with relatively
old construction methods suffered themost damage, and we also observedthat non-structural components placed

Photo 10: Tilting due to liquefaction

Damage to Nonstructural
Components

In buildings which did not suffer major

Photo 11: Damage due to a landslidefrom a sloped edge

Photo 12: Fallen exterior wall panels

Photo 13: Fallen ceiling at an airport
departure lobby (yellow dotted line
indicates where the ceiling droppage
occurred)higher suffered relatively more damage
and falling.
Concluding Remarks

Considering the size of the earthquake
and the instrumental seismic intensity
recorded at various locations, thedamage to building structures due toseismic movement was relatively little.
However, the degree of damage tobuildings designed according to the oldearthquake resistance standards was
greater. Looking ahead, it will be necessary to review technical standards, including measures to deal with ceilingcollapses and ground liquefaction,
which became significant problems inthe 2011 earthquake.
Finally, we would like to express
our deepest condolences to those wholost their lives in the tsunami and earthquake and to their families, and offer
our heartfelt sympathies to everyone
affected by the disaster.
Note: *1 NILIM/BRI: Report on the
Damage Investigation of Buildings
Due to the Mid Niigata Prefecture
Earthquake in 2004, pp.305–353,
October, 2006 (in Japanese)
The Japan Journal DECEMBER 201127