The 2nd Annual Meeting of the Strategic
Chinese-Korean-Japanese Cooperative Program
Jeju island, Korea, 2012/10/29-31

Site Amplification Study－Case of Taipei Basin－Kuo-Liang Wen
NCU, Taiwan

•Geological structure•Strong motion observations•Ground motion responses•Earthquake damages•Recent researchs

NW: SanChiao Fault

Three Faults

TaTun Volcano

KuanYin Volcano

LinKou Tableland

SE: Taipei Fault

Miocence RocksDepth contour to thebasement top
From deep drilling.
Central Geol. Surv.

台北盆地第三紀基盤面等深線及測線分布

Seismic survey

Quaternary Depositions
松山層景美層
五股層

板橋層

1:5

1:1

P and S
Velocities
1600
1800
2000
2400
3200

160
240
340
440

P-waveS-waveShape of SungShan Formation

SungShan Fm. Thickness

•Geological structure•Strong motion observations•Ground motion responses•Earthquake damages•Recent researchs

TSMIP Network
Taiwan Strong Motion
Instrumentation Program(TSMIP) is a plan operated from
July 1991 by the SOC, CWB.
The program installed morethan 600 digital free field strong
motion instruments, and 400 x 3
digital channels of strong motion
monitoring systems in nine
metropolitan areas.

Locations of the strong
motion stations in Taipei
area. Numbers indicate
the station codes ofTSMIP network (CWB).

IDS, A900
16 bits
Mem. ChipETNA
18 bits
PCMCIA
200 sps
250 sps (IDS)Downhole Arrays in Taipei Basin
A plan conducted by the CGS,
MOEA since Aug. 1991. This
project proposed the installationof downhole arrays in Taipei
Basin one site per year to analyze
the variation of seismic waves
propagated from basement toground surface.

In February 2002, the CGS
finished the research project andremoved it to IES. After few
months rearranging andplanning, four additional
downhole sites were underconsideration.

FBA23, FBA23DH  K2

19 bits, 200 sps

•Geological structure•Strong motion observations•Ground motion responses•Earthquake damages•Recent researchs

Ground Motion Responses
Earthquake ground motions
Microtremor survey
Theoretical modelingSource parameters of the Chi-Chi earthquake sequence
EventNo
1

2
3
4
5
6

7
8
9

Origin Time

Epicenter1999 9 20
17:47:16
1999 9 20
17:57:15
1999 9 20
18:03:41
1999 9 20
18:05:53
1999 9 20
18:11:53
1999 9 20
18:16:16
1999 9 20
21:46:37
1999 9 2200:14:41
1999 9 2200:49:43

23.85N
120.82E
23.91N
121.02E
23.79N
120.88E
23.95N
120.84E
23.85N
121.06E
23.84N
121.04E
23.60N
120.82E
23.83N
121.05E
23.76N
121.02E

Depth (km)

ML

87.3

2

6.5

4

6.6

20

6.0

5

6.7

4

6.7

5

6.6

8

6.8

96.3

Tapei Basin

1999/09/20 17:47
Chi-Chi earthquake

Spectral ratio contours of the Chi-Chi earthquake in the Taipei basin.

Spectral ratio contours of the Chi-Chi aftershocks in the Taipei basin.

Sungshan Formation Bottom- Taipei Basin -Mean spectral ratio obtained before the Chi-Chiearthquake. The earthquake used are occurred atsouth-eastern and eastern direction of the Taipei basin.

TSMIP測站微地動資料於2秒與0.5秒之Nakamura比等值圖。

WK

五股抽水站最大地動加速度與地下深度關係圖。
WKPeng&Wen(1998)

2D模擬
2D Modeling
WK site
0-30m: Q(f)=3.6f0.96
30-60m: Q(f)=7.2f0.99
60-90m: Q(f)=10.2f1.17
90-141m: Q(f)=40.7f1.24

台北盆地3D模擬3D Modeling三維理論模擬TSMIP
地表與參考站（TAP016）
於2秒之頻譜比等值圖•Geological structure•Strong motion observations•Ground motion responses•Earthquake damages•Recent researchs

Historical Damaged Earthquakes


Apr. 15, 1909

7.3

Nov. 15, 1986

6.8

Sep. 21, 1999

7.3



Mar. 31, 2002

6.8

1909/4/15
Taipei Eq.

1986/11/15
VHualien Eq.
IVIVIII

II

ML=6.8

3F

台北縣中和市員山路之華陽市場，原為三層多柱少牆鋼筋混凝土的市場建築物，由於2、3層改為住家後砌築了許多磚造外牆與隔間牆，使得建築物成為上剛下軟的結構，加上過大的超載，在耐震上十分不利。在此次地震襲擊下，幾乎大部份
一、二樓的支柱折斷，造成12人死亡，數十人受傷的慘劇。

14F

台北市復興南路一段某大廈，一樓剪力牆腳及牆邊構材部份被壓碎，鋼筋暴露且扭曲變形，牆面呈斜向之剪力龜裂，一、二樓間之混凝土樓板破裂
並下陷。

12F

台北市二棟大廈因棟距過近且振動頻率不相同，造成頂樓碰撞受損，5月20日花蓮地震受損後修補的位置再次損壞。

12F

台北市基隆路某汽車公司，門前與建築物中之鋼筋混
凝土柱暴裂，鋼筋扭曲變形。

13F

台北市基隆路一段某大廈外牆破壞情形，該大樓自9樓以下
電梯間大樑、樓梯間牆壁，大樓外牆均發生龜裂，部份樑柱牆壁龜裂處之水管斷裂；8樓之牆壁呈斜向之剪力破壞。

1986/11/15
ML=6.81~5F

忠孝大橋
陽明山瓦斯 西安街14F-裕台大樓* 13F-惠寶大樓* 12F-富貴大樓（必勝客）*

1986/11/15
ML=6.8

1999/9/21 Chi-Chi Eq.
Critical information
available in 102 seconds：
Time： 1:47 AM
Magnitude：ML7.3

Epicenter：Near Chi-Chi
Regional intensity map.
Shaking time histories.

1999/9/21Sungshan area

1999/9/21

Hsinchung area

Distribution of thecollapsedbuildings due tothe 1999 Chi-Chiearthquake < 5F

12F

20020331 Earthquake
25.35

March 31, 2002

Observed
24.85

ML=6.824.35

5人死亡
272人受傷

6.8
250
240
230
220
210
200
190
180
170
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
100

23.85

23.35

22.85

22.35

21.85
120.00120.50121.00121.50122.00122.50March 31, 2002

12~14F

Distribution of thecollapsed buildings
due to the 1999 ChiChi earthquake < 5F 12F

1~5F
1986/11/15
Hualien Eq.

SummaryThe low frequency responses on the western part of
the Taipei basin and Sungshan area are correlated withthe basin structure and the top soft soil layer (Sungshanformation).
The high frequency responses are mainly occurred
near the edge of the Taipei basin except the westernboundary of a steep structure.
The soft soil layer of the Sungshan formation may
dominate the site response in the Taipei urabn area.
During the 1986, Hualien earthquake and 1999,
Chi-Chi earthquake, there are some buildings damaged.
By comparing between the distribution of damagedbuildings and spectral ratio contours, we found that thepatterns can be correlated.

•Geological structure•Strong motion observations•Ground motion responses•Earthquake damages•Recent researchs

Strong motion station: 69
500 stations
Interval ~ 1 km

Locations of the microtremor survey points in the Taipei
area. Red symbols indicate the strong motion stations.

Dominant frequency contour in the Taipei basin area,
result from the H/V ratio of dense microtremor survey

0.5 Hz

2.0 HzH/V spectral ratio contours at 0.5 and 2.0 Hz.

H/V spectral ratio contour
at 0.5 Hz.

Sungshan Formation Bottom--- Taipei BasinInterval ~ 100 m

3D Finite-Difference Modeling of Strong
Ground Motion in the Taipei Basin
Model Setting
Modeling Parameters
Model diemnsion (km3)

28(W) x 28(L) x 2.5(H)Absorb boundary (grids)± 100

Source type

Source location (km)Source time function (sec)

Double-Couple(24,2,1)
0.16, 0.0, 0.16

Velocity (km/s2)
SunShang formation

Vp=1.5, Vs=0.86

Basin Basement

Vp=3.0, Vs=1.70

Outside the Basin

Vp=4.5, Vs=2.60

Basement +SunShang
Formation

2011.1修訂後公告之臺北盆地設計地震微分區圖
Microzonation Map of Taipei Basin in the Building Code Modified on 2011.

ESG 2011
4th IASPEI / IAEE International
Symposium:
Effects of Surface Geology on Seismic Motion
August 23–26, 2011
University of California Santa Barbara

Session 1: Recent Significant Earthquakes
Session 2: Site Response Modeling Using Borehole Data
Session 3: Ground Motion Simulation
Session 4: Nonlinearity in Site Response
Session 5: Spatial Variability of Ground Motions
Session 6: The Vs30 Debate: How We Can and Cannot Use
Vs30 in Site Response Estimation

The 5th ESG International Symposium will be held inTaipei, Taiwan, 2016 or 2017.
The main theme of the symposium and the date will bediscussed.

The 2nd Annual Meeting of the Strategic
Chinese-Korean-Japanese Cooperative Program
Jeju island, Korea, 2012/10/29-31

Thank you for your attention!
Kuo-Liang Wen
wenkl@earth.ncu.edu.tw