1

Brief review of building damage by the 2011 Tohoku Japan earthquake and following coping activities

Isao Nishiyama* (BRI), Izuru Okawa (BRI), Hiroshi Fukuyama (BRI) and Yasuo Okuda (NILIM)

BRI : Building Research InstituteNILIM : National Institute for Land & Infrastructure

Management

14th U.S.-Japan Workshop on Improvement of Structural Design and Construction PracticesDecember 3-5, 2012, Makena Beach & Golf Resort

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1. Introduction

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JMA Seismic Intensity & Hypocentral Region

★

Tohoku earthquakeMw=9.0 (14:46 JST on March 11, 2011)

450km (NS) x 150km (EW)

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Building and Residential Land Damage by Earthquake Motion and Tsunami

• BRI and NILIM sent 43 teams for field survey and the following reports are available as of December 2, 2012▫ http://www.kenken.go.jp/japanese/cont

ents/publications/data/132/index.html▫ http://www.kenken.go.jp/japanese/cont

ents/publications/data/135/index.html▫ http://www.kenken.go.jp/japanese/cont

ents/topics/20110311/0311report.html▫ http://www.kenken.go.jp/japanese/cont

ents/publications/data/138/index.html▫ http://www.kenken.go.jp/english/conte

nts/topics/20110311/0311summaryreport.html

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2. Recorded Ground and Building Motions

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BRI Strong Motion Network

134˚

134˚

135˚

135˚

136˚

136˚

137˚

137˚

138˚

138˚

139˚

139˚

140˚

140˚

141˚

141˚

142˚

142˚

143˚

143˚

144˚

144˚

145˚

145˚

146˚

146˚

34˚ 34˚

35˚ 35˚

36˚ 36˚

37˚ 37˚

38˚ 38˚

39˚ 39˚

40˚ 40˚

41˚ 41˚

42˚ 42˚

43˚ 43˚

44˚ 44˚

0 100 200

km

2011/03/1114:46(JST)h=24 km, M9.0

THU,SND

HCN2, HCNHRH

AKT

TRO

NIG

NGN

YMNSMZ

HKD

HKUKGC

SMS

NGY

MTS

OSK,SKS

HRO

KSOMIZ

IWK

MYK

ISK

01234567

IJMA

TAMA2,MIYA2

139˚20'

139˚20'

139˚40'

139˚40'

140˚00'

140˚00'

140˚20'

140˚20'

140˚40'

140˚40'

35˚20' 35˚20'

35˚40' 35˚40'

36˚00' 36˚00'

36˚20' 36˚20'

0 50

km

ANX, BRI, NCTD

NIT

CGC, CG2,CG3, NDLG,NDLM, NDLA

TUS

ICK

TKC

CHB

YCYFNB

EDG

UTK,NMW,SMD

TKD

ADC

MSTTDSAKB

TUF

KWS

KDI NKN

SITA, SIT2

YKH

MTK

01234567

IJMAYYG

In 1957, BRI started strong motion network.

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Damaged Building in Sendai city

−1000

0

1000

Acc

(cm

/s2 ) (a) Acc. in Trans. Dir.

−1000

0

1000

Acc

(cm

/s2 ) (b) Acc. in Long. Dir.

−40

0

40

Dis

p(c

m) (c) Bldg. Disp. in Trans. Dir.

−40

0

40

Dis

p(c

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

0.5

1.0

1.5

2.0

T(s

)0 50 100 150 200

Time (s)

(e) Transition of natural periods

Trans Long.

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

01F(Long.)09F(Long.)

Flexural failure of multi-story shear walls which can absorb large earthquake energy was observed. Though the building could secure human lives by preventing its collapse as demand of seismic codes, buckling and/or rupture of steel bars and steel plates in the columns and compressive crashing of concrete were observed. Finally, the building was demolished.

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Damaged Building in Sendai city (cont.)

• 1978

• 2011

-1000

0

1000(c

m/s

2 )202-01F (peak: 258 cm/s2)

-1000

0

1000

(cm

/s2 )

292-01F (peak:- 203 cm/s2)

-1000

0

1000

(cm

/s2 )

202-09F (peak: 1040 cm/s2)

-1000

0

1000

(cm

/s2 )

0 20 40 60 80 100 120 140 160 180 200Time (s)

292-09F (peak:- 529 cm/s2)

-1000

0

1000

(cm

/s2 )

192-01F (peak:- 333 cm/s2)

-1000

0

1000

(cm

/s2 )

282-01F (peak: 330 cm/s2)

-1000

0

1000

(cm

/s2 )

192-09F (peak: 908 cm/s2

-1000

0

1000

(cm

/s2 )

0 20 40 60 80 100 120 140 160 180 200Time (s)

282-09F (peak: 728 cm/s2)

1F(NS) 258 cm/s2

1F(EW) 203 cm/s2

9F(NS) 1040 cm/s2

9F(EW) 529 cm/s2

1F(NS) 333 cm/s2

1F(EW) 330 cm/s2

9F(NS) 908 cm/s2

9F(EW) 728 cm/s2

952+3 story building in Osaka city

• The large responses lasted at least 10 minutes in the building in Osaka, 770km from the epicenter. A 137cm maximum displacement occurred on the top floor.

• Many non-structural interior members such as ceilings, walls, fire doors, sprinklers, etc. were damaged, and even confinements of passengers in elevators occurred.

Displacement

-200

0

200

Dis

p.(c

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

-200

0

200

Dis

p.(c

m) 01F NW-SE (peak: 7.8 cm)

-200

0

200

Dis

p.(c

m) 52F SW-NE (peak: 137.1 cm)

-200

0

200

Dis

p.(c

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

-200

0

200

Dis

p.(c

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

-200

0

200

Dis

p.(c

m)

0 100 200 300 400 500 600 700Time (s)

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

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

0.5

1

5

10

50

100

Pseu

doVe

loci

tyR

espo

nse

(cm

/s)

0.1 0.5 1 5 10Period (sec)

0.01(cm) 0.1

110

1(cm/s/

s)10

100

1000

SW-NENW-SE

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3. Building and Residential Land Damage

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Field surveyed area by BRI and NILIM teams

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Earthquake Motion Damage

Courtesy to the Japan MLIT

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Earthquake Motion Damage (cont.)

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Tsunami Damage

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4. Coping Activities on Selected Issues

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System to Revise Building Structural Codes

Building Structural Code Committee Building Structural Code

NILIM

WGLong-duration long-period earthquake ground motions

R & D by self-budget

TGCeiling design method, etc.

MLIT

BRI

proposal

technical advice On Building Structural Codes,* Proposal* Public comments* Technical information

Private

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1. Digital data by BRI strong motion network2. Long-duration and long-period ground motion,

structural performance under multiple cycles of loadings

3. Higher level of PBD, functional after earthquake4. Fall down of ceilings in spatial structures and

escalators in shopping centers5. Fractured lead damper in seismically isolated

buildings6. Inclination due to liquefaction in residential

houses7. Evaluation of tsunami force 8. etc.

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2011.3.11 Tohoku EQ.

Revision of the model

Philippine Sea plate

Earthquakes used in the analysesRevised evaluation method

Long-duration and long-period motion properties・Spectral amplitudes from large earthquakes・Duration of motions with each frequency band

・earthquake magnitude・distance・site specific coefficients

・ Epicenters・ Paths＋

（additional factors）

Paci

fic p

late

ORIGINAL EVALUATION MODEL

MLIT PROPOSAL FOR DESIGN MOTIONCALL FOR PUBLIC COMMENTS, 2010

Long-duration and long-period ground motion prediction method based on observation at about 1600 stations

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132˚ 136˚ 140˚

32˚ 32˚

36˚ 36˚

0 100 200

kmNankai

Tonankai

Tokai

Long-duration and long-period motions were evaluated for major urban areas with two-, three- connected earthquakes, by HERP, CAO, AIJ, etc. MLIT is going to propose a design long-duration and long-period motions and is funding project for the purpose.

NagoyaOsaka Tokyo

HERP

CAO Mw9 model

Nankai

Nankai-troughthree-connected earthquake model with revised modelfor major areas

Long-duration and long-period ground motion prediction method based on observation at about 1600 stations (cont.)

20Structural performance against long-duration and long-period ground motions (full-scale)

These large-size experiments are carried out under the research cooperation between the BRI and the institutions headed by Obayashi, Kajima and Taisei Co.

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Fall down of ceilings in spatial structures• After Geiyo earthquake (2001), a technical advice was issued

to recommend putting diagonal braces on ceiling rods, and keep clearance around suspended ceiling. (see left figure)

• Construction companies reported nearly 2,000 cases of fall down of ceilings during Tohoku earthquake. Examples with/without injury are compared. (see right figure)

Recommended method in an MLIT technical advice

Frequently observed damage by earthquake

Mass and height of ceiling damaged by earthquake

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Fall down of ceilings in spatial structures(cont.)• (Tentative) Allowable Stress Design for

probable earthquake + safety margin▫ Scope of regulation Ceiling height > 6m Ceiling area > 200m2

Unit weight of ceiling > 2kg/m2

▫ Safety margin Vertical strength Clearance around ceiling

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Fall down of escalators in shopping centers

• (Tentative) Requirement from H/100 (current) to H/40• (Tentative) Exceptional relaxation to H/100 in case of

fall prevention device

HH/100

Fixed

Escalator truss

Roller overlapped

Esc

alat

or tr

uss

FloorGirder

Joint cover

Fall prevention

Connector

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Liquefaction

• Liquefaction evaluation was made by FL-method at 112 sites in Kanto area, the results were compared with observations.

• Liquefied sites ( ) are all predicted (FL≦1) but many non-liquefied sites are cautioned( ).

• Improvement of evaluation accuracy is in need.

• FL-method requires following information.▫ N-value by standard penetration test (SPT)▫ fine fraction content▫ water level▫ maximum design horizontal acceleration at

surface▫ earthquake magnitude

Liquefiedsites

Non-liquefiedsites

FL＞1

FL≦1 53 35

240

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Liquefaction (cont.)

• Japan’s Building Standard Law does not require structural calculation for detached residence (residential land) ▫ Liquefaction risk is not evaluated▫ Liquefaction measures are not required

• Show menus and leave selection to owners▫ Development of affordable liquefaction evaluation method for

residential land BRI tries possibility of SWS (Swedish weight sounding test), plus

water level and soil judgment▫ Development of practical techniques for residential land Applicability to existing house Prediction of subsidence

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Tsunami wave force- Tentative guidelines for tsunami evacuation buildings -

Previous guidelinesPartially relaxed current guidelines (tentative guidelines)Observed results by Tohoku Japan earthquake

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Tsunami wave force (cont.)- Tentative guidelines for tsunami evacuation buildings -

• BRI, Kajima Co. and U. of Tokyo have carried out waterway experiments in order to develop (improve) CFD (Computational Fluid Dynamics) technique for evaluation of tsunami pressure on buildings.

• Improved CFD technique will be applied to evaluate the effects of openings, water infiltration, etc.

• AIJ discusses adding new chapter of tsunami loads on buildings into “(Revised) Recommendations for Loads on Buildings” in 2014.

Waterway experiment Numerical simulation of Tsunami over seawall

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Thank you for your kind attention.