Proceedings of the International Symposium on Engineering Lessons Learned fromthe 2011 Great East Japan Earthquake, March 1-4, 2012, Tokyo, JapanSTRONG MOTION DATA RECORDED IN
BUILDINGS DAMAGED BY THE 2011 GREATEAST JAPAN EARTHQUAKE
Toshihide KASHIMA1, Shin KOYAMA2, Izuru Okawa3 and Masanori IIBA4
1

Senior Research Engineer, IISEE, Building Research Institute,Tsukuba, Japan, kashima@kenken.go.jp
2
Chief Research Engineer, IISEE, Building Research Institute,Tsukuba, Japan, skoyama@kenken.go.jp
3
Senior Research Fellow, IISEE, Building Research Institute,Tsukuba, Japan, okawa@kenken.go.jp
4Director, IISEE, Building Research Institute,Tsukuba, Japan, iiba-m@kenken.go.jp

ABSTRACT: Building Research Institute (BRI) has initiated construction and operationof the strong motion network aimed at building structures in 1957, as one of its research
activities. Fifty-nine stations in the BRI strong motion network were triggered by the2011 Great East Japan Earthquake. The paper reported notable cases recorded during theEast Japan Earthquake and its aftershocks in the BRI strong motion network.
Key Words: Great East Japan earthquake, strong motion data, building damage

INTRODUCTION
The Building Research Institute (BRI) of Japan is a national institute engaging the research anddevelopment in the field of architecture, building engineering and urban planning. BRI has initiatedconstruction and operation of the strong motion network aimed at building structures in 1957, as oneof its research activities (Kashima, 2006a).
On March 11, 2011, a massive earthquake occurred off the Pacific coast of northeastern Japan.
The earthquake (hereinafter referred to as the East Japan earthquake) caused devastating tsunami andsevere shaking in extensive area.
Fifty-nine stations in the BRI strong motion network were triggered by the East Japan earthquake.
Most of the stations experienced the strongest shaking ever. Among buildings in the BRI network, atleast four buildings suffered some damage due to the severe earthquake motions. Through the analysesof strong motion data recorded in those buildings, obvious change of the natural periods during intense
shaking could be identified.
The paper reported notable cases recorded during the East Japan Earthquake and its aftershocks in
the BRI strong motion network.

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OUTLINE OF STRONG MOTION DATAThe East Japan earthquake has triggered 59 stations of the BRI strong motion network as shown in Fig.
1. The stations were widely distributed over the eastern Japan, and nearly 30 stations were located in
the Tokyo metropolitan area and its outskirts. Almost buildings in the network have experienced themost severe earthquake motion in the past. Among buildings in the BRI network, at least fourbuildings in the three stations suffered some damage due to the intensive earthquake motions. The
maximum accelerations recorded in the three stations are listed in Table 1.
44˚134˚ 135˚ 136˚ 137˚ 138˚˚139˚ 140˚ 141˚ 142˚ 143˚ 144˚ 145˚ 146

43˚44˚

43˚

HKU

KGC
HRO

42˚139˚20'
36˚20'

42˚139˚40'

140˚20'140˚00'140˚40'36˚20'HKD
41˚41˚HRH

40˚

ANX, BRI,NCTD
TKC

HCN2, HCN
40˚

MYK

AKT

NIT

36˚00'

39˚

TRO
38˚

NIG

2011/03/11
14:46(JST)h=24 km, M9.0

THU,
SND

37˚

KDI

37˚

IWK

36˚00'

36˚

MIZ
OSK,
SKS
MTS

135˚136˚

KSO
YMN
NGY
SMZ

137˚138˚139˚140˚0141˚

NKN

TDS
AKB
ADC
EDG
TKD

142˚

143˚100

144˚

CGC, CG2,CG3, NDLG,TUF
NDLM, NDLAKWS

35˚kmSMSYCYICKFNB35˚40'

CHBkm

YKH

200

145˚

TUSMST35˚40'

36˚35˚

SITA, SIT2UTK,NMW,SMD

38˚

NGN

34˚134˚

MTK39˚034˚35˚20'
146˚
139˚20'139˚40'140˚00'50

140˚20'35˚20'
140˚40'Fig. 1 Triggered stations in the BRI strong motion network
Table 1 Maximum accelerations in three stations of damaged buildings
CodeStation nameΔ(km)

IJMA

THU

Tohoku University

177

5.6

IWKIwaki City Hall

210

5.3

ANX

Annex and Main
Buildings, Building
Research Institute3305.3Az.

Loc.

01F*
09F
B1F*
180°
09F
A01*A89
BFE
180°
8FE
MBC
M8C
192°

Max. Acc. (cm/s2)
Note
H1
H2V
333
330
257
908
728
640
175
176
147
579
449
260
279
227
248 GL
142
153
102 GL-89 m
194
191
136 Annex
597
506
344 Annex
203
206
152 Main bldg.
682
585
311 Main bldg.

Note) Δ: Epicentral distance, IJMA: JMA instrumental seismic intensity (using an asterisked sensor), Loc.:Sensor location, Az.: Sensor direction (clockwise from North), H1, H2, V : Maximum accelerations inhorizontal #1 (Az.), horizontal #2 (Az.+90°) and vertical directions

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THU BUILDINGAt the station THU, a nine-story steel-framed reinforced concrete building in the Aobayama Campusof Tohoku University, Sendai city, is the target of instrumentation. This building has a long history ofstrong motion observation. Among them, strong motion records on the ninth floor of the building thatwere obtained in the 1978 Miyagi-ken-oki (Off Miyagi prefecture) earthquake are well known to haverepresented a maximum acceleration of more than 1,000 cm/s2. The instrument has two acceleration
sensors on the first floor (01F) and the ninth floor (09F).
During the East Japan earthquake, multi-story shear walls suffered serious bending failure. Figure
2 shows acceleration waveforms recorded during the main shock of the East Japan earthquake. Upper
two waveforms are accelerations on the first floor (01F) in the transverse (N192°E) and longitudinal(N282°E) directions, and lower two are on the ninth floor (09F). Maximum accelerations on the firstfloor (01F) exceeded 330 cm/s2 in both of the directions. Maximum accelerations on the ninth floor(09F) were twice to three times larger than that on the first floor, and exceeded 900 cm/s2 in thetransverse direction.
Pseudo velocity response spectra with a 5% damping ratio of the acceleration records on the firstfloor (01F) are plotted in Fig. 3. The highest peak around the period of 1 second in the N192°E
direction is striking. At that period, the velocity response reaches 179 cm/s.
Figure 4 (a) and (b) represent building displacements (relative displacement of the ninth floor tofirst floor) in the both directions, and Fig. 4 (c) shows fundamental natural periods of the building thatwere estimated in every 10 seconds (Kashima, 2006b). The fundamental natural periods in Fig. 4 (c)represented about 0.7 seconds at the initial time of the earthquake motion in both of the directions, butincreased to about 1 second in the first wave group at the time of 40 to 50 seconds, and increased from
1.2 seconds to about 1.5 seconds in the second wave group at the time of 80 to 100 seconds. Due to theseismic damage, the fundamental natural periods finally became twice longer than the natural periods
at the initial stage. It can be estimated that the stiffness of the building was reduced to 1/4.

Photo 1 THU building

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1000Acceleration(cm/s/s)

192-01F (peak:- 332.8 cm/s/s)
0(cm/s/s)

-1000
1000

282-01F (peak: 329.8 cm/s/s)

0-10001000(cm/s/s)

192-09F (peak: 908.3 cm/s/s)
0(cm/s/s)

-1000
1000

282-09F (peak: 728.4 cm/s/s)

0-1000
020

40

60

80

100
Time (sec)

120

140

160

180200Fig. 2 Acceleration waveforms recorded in THU building
Pseudo Vel. Resp. Spectrum (h=5%)1010000

200

10010(cm/s/s)

501010Pseudo Velocity Response (cm/s)

1005)

1cm1(0.

20.1

192-01F282-01F
0.51Period (sec)

510Fig. 3 Pseudo velocity response spectra of the strong motion record on 01F at THU (h=5%)
Disp (cm)40(a) Bldg. Disp. in N192E0Disp (cm)

−4040(b) Bldg. Disp. in N282E

0T (s)−402.0(c) Natural period

1.51.0N192E

N282E

0.5050100Time (s)150200Fig. 4 Building displacements and fundamental natural periods of THU building

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IWK BUILDINGThe Iwaki City Hall that is an eight-story steel-framed reinforced concrete building is instrumented inthe station IWK. Two acceleration sensors are placed on the first basement floor (B1F) and thepenthouse floor (09F). The appearance of the building is shown in Photo 2. The epicentral distance of
the IWK station was 210 km.
Severe earthquake motion of the East Japan earthquake caused cracks on some concrete walls anddamages to finishing materials in the building. Acceleration records of the East Japan earthquake areshown in Fig. 5. The first wave group composed mainly of S-waves appeared at the time of around 30
seconds. Earthquake shaking continued for long time and the maximum amplitudes were recorded
around the time of 80 to 90 seconds. The maximum accelerations on the basement floor (B1F) were
175 cm/s2 and 176 cm/s2 in the transverse (N180°E) and longitudinal (N270°E) directions, respectively.
On the building top (09F), those were amplified to 579 cm/s2 and 449 cm/s2 (3.3 and 2.5 times) in theN180°E and N270°E directions, respectively.
Figure 6 represents pseudo velocity response spectra with 5% damping ratio of the records on thebasement floor (B1F). The response spectra shows a form like a loose hill and the maximum velocity
response exceeded 100 cm/s at the periods of around 2 seconds in the N180°E direction.
Figure 7 (a) and (b) indicate building displacements in the N180°E and N270°E directions. The
maximum building displacement reached 11 cm in the N180°E direction. Natural fundamental periods
identified from the strong motion in every 10 seconds are plotted in Fig. 7 (c). The natural period in
the N180°E direction was 0.6 seconds in the initial time. The intensive shaking lengthened the natural
period to 0.8 seconds at the time of around 40 seconds, and then to 1 second at the time of 100 seconds.
The similar phenomenon can be observed in the transition of the natural periods in the N270°E
direction.

Photo 1 IWK building1173

Acceleration

600(cm/s/s)

180-B1F (peak:- 174.6 cm/s/s)
0-600
600(cm/s/s)

270-B1F (peak: 176.1 cm/s/s)
0-600
600(cm/s/s)

180-09F (peak:- 578.5 cm/s/s)
0-600
600(cm/s/s)

270-09F (peak: 448.9 cm/s/s)
0-600
020406080

100Time (sec)120140160

180200Fig. 5 Acceleration waveforms recorded in IWK building
Pseudo Vel. Resp. Spectrum (h=5%)1010000

200

10010(cm/s/s)

501010Pseudo Velocity Response (cm/s)

1005)

1cm1(0.

2
0.1

180-B1F
270-B1F
0.51
Period (sec)

510Fig. 6 Pseudo velocity response spectra of the strong motion record on B1F at IWK (h=5%)
Disp (cm)15(a) Bldg. Disp. in N180E0Disp (cm)−1515(b) Bldg. Disp. in N270E0T (s)−151.5(c) Natural period

1.00.5N180E

N270E

0.0050100Time (s)150200Fig. 7 Building displacements and fundamental natural periods of IWK building

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ANX BUILDINGSThe station ANX has a densely instrumented system targeted on two buildings and the surrounding
ground in the Building Research Institute (BRI) in Tsukuba City, Ibaraki Prefecture. The target isequipped with eleven acceleration sensors in the annex building, seven sensors in the surrounding
ground, and four sensors in the main building. The annex building is an eight-story steel-framed
reinforced concrete building with one basement floor, and the main building is a seven-story
steel-framed reinforced concrete building with one basement floor. Two buildings are connected by thepassage way with the expansion joint. Photo 3 shows the annex building and main building of BRI andFig. 8 indicates the sensor configuration.
The East Japan earthquake violently shook and damaged both of the buildings. Especially in thepassage way between the two buildings, the expansion joints were broken and ceiling boards fell off.
Figures 9 and 10 indicate acceleration waveforms recorded in the annex and main building,respectively. Maximum accelerations on the basement floors (BFE and MBC) are about 200 cm/s2 inthe both of the buildings. Accelerations on the eighth floors (8FE and M8C) are 2.5 to 3.0 times larger
than that on the basement floors.
Pseudo velocity response spectra of the strong motion data recorded on the basement floors of theboth buildings are plotted in Fig. 11. Several peaks appear on the spectra in the both horizontal
directions, and the pseudo velocity response at the period of 1.3 seconds exceeds 100 cm/s.
Building displacements and transition of the fundamental natural periods of the annex building
and the main building are shown in Figs. 12 and 13, respectively. Although the natural periods in bothof the horizontal directions of the annex building were initially less than 0.8 seconds, those weregradually getting longer during the main part of the shaking. Finally the natural periods reached morethan 1.0 second in the both directions. In case of the main building, the natural periods were 0.7
seconds and 0.45 seconds in the transverse (N180°E) and longitudinal (N270°E) directions,respectively. At the end of strong shaking, the natural periods were lengthened to about 1 second in theN180°E direction and 0.7 seconds in the N270°E direction.
In order to discuss damage to the expansion joint, displacements of the expansion joint arecalculated. Figure 14 shows relative displacements of the annex building and the main building to therespective foundation, and relative displacement of the annex building side of the expansion joint tothe main building side. Figure 14 (a) and (b) represent building displacements in the N180°E andN270°E directions, respectively. In Fig. 14 (a) and (b), solid lines indicate displacements of the annexand dashed lines represent those of the main buildings. The both buildings show similar movement in
the N180°E direction because of close fundamental natural period. In contrast, movement of the twobuildings in the N270°E direction is quite different with each other.
Figure 14 (c) and (d) show expansion joint displacements in the N180°E and N270°E directions,respectively. Maximum displacement of the expansion joint direction reaches 12 cm in the N270°E
and exceeded the clearance of the expansion joint.

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Photo 3 Instrumented buildings of ANX station
D

7.5

Annex

C

3.0

9.0

G

M8C
MainMBC,
Building

7.5

8.0

FE

BFE, 8FE

B

9.0

9.0

DAC

7.5

7.5

12

6.0
3

6.5

7.2

4

7.2
2

1

7.2
37.24

7.2

7.2

5

B1F Plan

67.2
7270°

7.2

7.2
8910NA01180°

4.2(a) B1F Plan

8FE5FW5FE

M8E
3.7

M8C

8FN, 8FS

3.7

3.7

3.7

3.7

5.1

2.35

Exp.J

3.7
3.8

2FW

4.3

4.3

3.8

3.7

3.7

3.7

M5C2FE

BFE

6.35

BFN, BFS

MBC

2.75

2.5

6.0

1FE

7.5
1

7.5
2

6.0
3

6.5
4

7.2
1

7.2
2

7.2
3

7.2
4

7.2
5

7.2
6

7.2
7Section(b) Elevation
Fig. 8 Sensor configuration at ANX station

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7.27.28910

(cm/s/s)

800

Acceleration
180-BFE (peak: 193.9 cm/s/s)

0(cm/s/s)-800
800
270-BFE (peak: 191.0 cm/s/s)
0(cm/s/s)-800
800
180-8FE (peak:- 597.0 cm/s/s)
0(cm/s/s)-800
800
270-8FE (peak: 505.5 cm/s/s)
0
-800
0

20

40

60

80

100
Time (sec)

120

140

160

180

200

Fig. 9 Acceleration waveforms recorded in annex building at ANX(cm/s/s)

800

Acceleration
180-MBC (peak: 203.1 cm/s/s)

0(cm/s/s)-800
800
270-MBC (peak: 206.1 cm/s/s)
0(cm/s/s)-800
800180-M8C (peak:- 682.0 cm/s/s)
0(cm/s/s)-800
800
270-M8C (peak: 585.1 cm/s/s)
0-800
020406080

100Time (sec)

120

140

160

180200Fig. 10 Acceleration waveforms recorded in main building at ANX
Pseudo Vel. Resp. Spectrum (h=5%)
10

10

000

200

10010(cm/s/s)

50

1010

Pseudo Velocity Response (cm/s)

100

180-BFE
270-BFE
180-MBC
270-MBC5)

1cm1(0.

2
0.1

0.5

1
Period (sec)

510Fig. 11 Pseudo velocity response spectra of the strong motion records at BFF and MBC (h=5%)1177

Disp (cm)15(a) Bldg. Disp. in N180E0Disp (cm)−1515(b) Bldg. Disp. in N270E0T (s)−151.5(c) Natural period

1.0N180E
N270E

0.50.0050100Time(s)150200Fig. 12 Building displacements and fundamental natural periods of annex building at ANX
Disp (cm)15(a) Bldg. Disp. in N180E0Disp (cm)−1515(b) Bldg. Disp. in N270E0T (s)−151.5(c) Natural period

1.00.5N180E

N270E0.0050100Time(s)150200Fig. 13 Building displacements and fundamental natural periods of main building at ANX(cm)

15(cm)

Bldg. Disp. (N270E)

Annex Bldg.
Main Bldg.

0−1515(cm)Annex Bldg.
Main Bldg.

0−1515Exp. J. Disp. (N180E)

0−1515(cm)Bldg. Disp. (N180E)

Exp. J. Disp. (N270E)

0−158090100Time (s)110120Fig. 14 Building displacements and expansion joint displacements at ANX1178

CONCLUSIONSThe BRI strong motion network has obtained a large number of strong motion data from the 2011 East
Japan earthquake and its aftershocks and induced earthquakes. In some buildings, strong motion dataclearly identified damage process by the intensive earthquake motions. The analysis of the data
recorded in two buildings at the station ANX suggests lack of the clearance of the expansion joint.
In the BRI network, we have various types of buildings, including nine super-high-rise buildings
and six base isolated building. We intend to contribute to the improvement of the seismic safety ofbuilding structures through the analyses of the extensive strong motion data.

ACKNOWLEDGMENTS
The authors express our gratitude to persons who are cooperation the BRI strong motion project.

REFERENCES
Kashima, T. and Y. Kitagawa (2006a). “Dynamic Characteristics of Buildings Estimated from StrongMotion Records,” Proceedings of the 8th U.S. National Conference on Earthquake Engineering,
Paper No. 1136
Kashima, T. and Y. Kitagawa (2006b). “Dynamic Characteristics of An 8-storey Building Estimatedfrom Strong Motion Records,” Proceedings of the First European Conference on Earthquake
Engineering and Seismology, Paper No. 1005

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