Seismic Performance of Base Isolation Buildings during 2003 Off Tokachi Earthquake

Taiki SAITO

Building Research Institute, JAPAN

( tsaito@kenken.go.jp ) 1

Outline

2003 Off Tokachi Earthquake Characteristics of earthquake Damage photos

Earthquake response of base isolation buildings Government building Office building Hospital Bank

Summary

2

2003 Off Tokachi Earthquake

Date: 26th September, 2003

Time: 4:50 am

Magnitude: 8.0

Location: 41°46.78'N 144°4.71'E

Depth: 42km

Missing: 2 people

Injured: 847 people

3

JMA Intensity Map

(Data: JMA) 4

Damage by Tsunami after the earthquake

(Photos from Hokkaido Journal) 5

Damage of roads

(Photos from Hokkaido Journal) 6

Damage of buildings

(Photos from Hokkaido Journal) 7

Damage of buildings

(Photos from Hokkaido Journal) 8

Damage of Oil Tank

(Photos from Hokkaido Journal)

Natural Period for Sloshing= 7 sec

Tomakomai City (220 km from Epicenter)

9

Effect of long period earthquake

(Data: Disaster Prevention Research Center)

7 sec

Contour Map for Response Velocity (T=7 sec)

Earthquake Velocity Wave (0.05-0.5Hz)

Tomakomai

10

Base isolation buildings in Kushiro city

140°

140°

141°

141°

142°

142°

143°

143°

144°

144°

145°

145°

146°

146°

38° 38°

39° 39°

40° 40°

41° 41°

42° 42°

43° 43°

44° 44°

0 100 200

km

HRO

HKU

HKD

HCN, HCN2

MYKAKT

THU

HRH

KGC

Mainshock09/26 04:50M8.0, h=42kmAftershock

09/26 06:08M7.1, h=21km

11

[1] Government office building

SRC structure with steel braces

9-story building with 1-story basement

Reference:

T.Kajima, A.Ito, H. Fujita,

“Earthquake record of 2003 Off Kushiro Earthquake at Kushiro-government office”, Mensin Journal, pp. 36-38, N0.43, 2004.2

12

Allocation of base isolation devices

0 5 10m

N

01F, 09F B1F

33 m29

mGL, G10, G34

0 10 20 m

G34

G10

GL

B1F

01F

09F

29 m

64 Natural rubber bearings, 56 lead dampers and 32 steel dampers

Sensor

13

Observed records

Acceleration

-300

0

300

Acc

. (c

m/s

/s)

257-09F (peak: 120.6 cm/s/s)

-300

0

300

Acc

. (c

m/s

/s)

257-01F (peak:- 80.6 cm/s/s)

-300

0

300

Acc

. (c

m/s

/s)

257-B1F (peak: 192.4 cm/s/s)

-300

0

300

Acc

. (c

m/s

/s)

257-GL (peak:- 259.8 cm/s/s)

-300

0

300

Acc

. (c

m/s

/s)

257-G10 (peak: 214.4 cm/s/s)

-300

0

300

Acc

. (c

m/s

/s)

0 10 20 30 40 50 60 70 80 90 100 110 120Time (sec)

257-G34 (peak: 134.5 cm/s/s)

Place

Maximum Acc,(cm/s2)

N167°E N257°EUD

Building

09F 93.8 120.6 183.6

01F 70.3 80.6 85.1

B1F 154.1 192.4 76.4

Ground

GL 210.2 259.8 106.3

G10 173.3 214.4 71.9

G34 137.6 134.5 61.5

14

Distribution of max. acceleration response

-40

-30

-20

-10

0

10

20

30

40

0 100 200 300

Peak Acc. (cm/s/s)

Hei

ght

(m)

Ground N167E

Ground N257E

Building N167E

Building N257E

09F

01F

B1F

GL

G10

G34

15

Orbit of displacement

-15

0

15

-15 0 15Disp (cm)

Dis

p. (

cm)

N

0 5 10m

N

01F, 09F B1F

33 m

29m

GL, G10, G34

16

[2] Office building

RC wall structure

3-story building

Reference:

Y.Takenaka, T.Yasuda, Y. Suzuki,

“Earthquake observation of base isolation building in Kushiro city at 2003 Off Kushiro Earthquake”, Mensin Journal, pp. 31-35, N0.43, 2004.2

17

Allocation of base isolation devices

1

A

2

B

X

Y

Base Isolator : 600 φ

▽

装置芯 装置芯 ▽ Basement Sensor

1FL Sensor

RFL Sensor

Scratch Board

4 Lead rubber bearings

18

Base isolation devices

Lead rubber bearing

19

Distribution of max. acceleration response

0 100 200 300

X(EW)Y(NS)

(Gal)Input

1FL

RFL

0 20 40 60 80 100-300

0

300

(sec)

(Gal)

0 20 40 60 80 100-300

0

300

(sec)

(Gal)

Ｘ (EW) Ｙ (NS) UD

RFL 228 141 －

1FL 229 129 －

BasementInput 286 274 114

0 20 40 60 80 100-300

0

300

(sec)

(Gal)

20

Orbit of displacement

-40 -30 -20 -10 0 10 20 30-20

-10

0

10

20(cm)

(cm)

X(EW)

Ｙ (NS)

21

[3] Hospital building

RC structure

3-story building with penthouse

Fist base isolation hospital in Japan

Reference:

S.Sakai, Y.Ito, T.Iida,

“Earthquake respnse of base isolation hospital”, Mensin Journal, pp. 41-43, N0.43, 2004.2

22

Allocation of base isolation devices

50 High damping rubber bearings

23

Observed records

.UD基礎

-250

0

250

0 50 100 150Time (sec)

Acc

. (c

m/s

2 )

.NS基礎

- 250

0

250

0 50 100 150Time (sec)

Acc

. (c

m/s

2 )

.EW基礎

- 250

0

250

0 50 100 150

Time (sec)

Acc

. (c

m/s

2 ) MAX=212cm/ s2

MAX=142cm/ s2

MAX=100cm/ s2

.NS１階

- 250

0

250

0 50 100 150Time (sec)

Acc

. (c

m/s

2)

.EW１階

- 250

0

250

0 50 100 150Time (sec)

Acc

. (c

m/s

2 ) MAX=155cm/ s2

MAX=123cm/ s2

.UD１階

- 250

0

250

0 50 100 150

Time (sec)

Acc

. (c

m/s

2)

MAX=145cm/ s2

MAX= 212 cm/s2 (EW)

MAX= 142 cm/s2 (NS)

MAX= 100 cm/s2 (UD)

MAX= 155 cm/s2 (EW)

MAX= 123 cm/s2 (NS)

MAX= 145 cm/s2 (UD)

24

Distribution of max. acceleration response

0 100 200 300

EWNS

RF

3F

2F

1F

BF

25

-15

0

15

20 40 60 80 100 120Time (sec)

Rel

. Dis.

cm)

（

EW

-15

0

15

20 40 60 80 100 120Time (sec)

Rel

. Dis.

cm)

（

NS

-1.0

0.0

1.0

20 40 60 80 100 120Time (sec)

Rel

. Dis.

cm)

（

UD

MAX=13.1cm

MAX=9.8cm

MAX=0.27cm

NS

EW

UD

NS

- 15.0

- 10.0

- 5.0

0.0

5.0

10.0

15.0

- 15.0 - 10.0 - 5.0 0.0 5.0 10.0 15.0

→ (cm)東西方向変位 【東 】

→

cm

南北

方向

変位

【北】

（）

N

EW

Orbit of displacement

26

[1] Banking facility

SRC structure

７ -story building with 1-story basement and penthouse

Reference:

M.Todo, H.Seki,

“Earthquake record of 2003 Off Kushiro Earthquake at Kushiro-bank headquarter”, Mensin Journal, pp. 39-40, N0.43, 2004.2

27

Allocation of base isolation devices

15 Natural rubber bearings, 11 lead dampers, and 6 steel dampers

28

Base isolation devicesnatural rubber bearing

lead dampersteel damper

29

- 500- 400- 300- 200- 100

0100200300400500

- 6 - 4 - 2 0 2 4 6

Drift (cm)

Load

(ton

f)Experiment

Estimation

Characteristics of base isolation devices

30

BF X- dir. (max 172)

- 250

0

250

0 10 20 30 40 50 60sec.

gal

1F X- dir. (max 141)

- 250

0

250

0 10 20 30 40 50 60sec.

gal

Acceleration response (X-direction)

31

BF Y- dir. (max 222)

- 250

0

250

0 10 20 30 40 50 60sec.

gal

1F Y- dir. (max 162)

- 250

0

250

0 10 20 30 40 50 60sec.

gal

Acceleration response (Y-direction)

32

Basement Drift

- 20

0

20

- 20 0 20cm

cm

Y

X

Observed Basement Drift

- 20

0

20

0 10 20 30 40 50 60sec.

cm

X (max 14cm)Y (max 11cm)

Orbit of displacement

33

0

50

100

150

200

250

300

350

1-X 1-Y 2-X 2-Y 3-X 3-Y 4-X 4-Y I-X I-Y II-X II-Y

Max

. Acc

. (cm

/s2)

BF1F

Summary of base isolation effect

34

　　 　 1 2 3 4 (1995 Kobe earthquake)

0.45 0.42

0.80

0.470.73

0.870.82

0.73

0.35

0.22

0.95

0.54

-15

0

15

-15

0

15

Dis

p (cm

)

Disp. (cm)

N

Basement Drift

- 20

0

20

- 20 0 20cmcm

Y

X

- 15.0

- 10.0

- 5.0

0.0

5.0

10.0

15.0

- 15.0 - 10.0 - 5.0 0.0 5.0 10.0 15.0

→ (cm)東西方向変位 【東 】

→

cm

南北

方向

変位

【北】

（）

N-40 -30 -20 -10 0 10 20 30

-20

-10

0

10

20(cm)

(cm)

Summary of displacement

Building 1 Building 2

Building 3 Building 4

35