Transcript Seismic Performance Analysis of Earth Dam

Seismic Performance Analysis of Earth Dam Case Studies
During Chi-Chi Earthquake
J. C. Chern
Geotechnical Engineering Research Center
Sinotech Engineering Consultants, Inc.
November 3, 2003
Presentation Outline
• Introduction
• Performance of Earth Dam During Chi-Chi
Earthquake
• Case Studies
– Shuisheh Dam
– Tousheh Dam
– Liyutan Dam
• Reliability of Seismic Safety Analysis for Earth
Dam
• Conclusion
Liyutan Dam
Shuisheh Dam
Tousheh Dam
Chelungpu Fault
Hsinshan
Hsisheh
Yenshan
Shehmen
Chingtsoho
Jonhoshan
Baoshan
Dapu
Mingdeh
Chingtan
Feitsui
Louhou
Jonhua
Liyutan
Dehchi
Kukuan
Tienlun Chingshan
Shehkang
Chelungpu Fault
Liwu
Wusheh
Shuisheh
Minghu
Mingtan
Wuchieh
Shuilien
Tousheh
400
Tonkui
Neipu
Lantan Jenyitan
Baiho Luliao
Chienshanbei
0
30
0
20
Tsengwen
Wushantou
Whotoubei
Nanhua
Chingmien
Earth Dam
Arch Dam
Ahkundien
Concrete Gravity Dam
Chelongpu Fault
Fengshan
Mudan
Table 1 : Observed performances of earth dams
Case
No.
Dam
Dam Type
Height (m)
a max
at
damsite (g)
1
Tsengwen
ERTH
133.0
< 0.1*
2
Liyutan
ERTH
96.0
0.13
3
Nanhua
ERTH
87.5
0.037
4
Yunhoshan
ERTH
62.5
< 0.1*
5
Mudan
ERTH
62.5
< 0.1*
6
Wushantou
HYDF
56.0
< 0.1*
7
Baoshan
ERTH
34.5
0.23
8
Lantan
ERTH
31.0
0.25*
9
Shuisheh
ERTH
30.3
0.58*
10
Jenyitan
ERTH
28.0
0.68**
11
Tousheh
ERTH
19.1
0.58*
*Estimated Value
**Chiayi earthquake, Oct. 22, 1999
Observed Performance
max=0.002%
no abnormal
max=0.1%
cracking near abutment
max=0.01%
no abnormal
No abnormal
max=0.016%
no abnormal
max=0.05%
no abnormal
max=0.003%
no abnormal
max=0.08%
no abnormal
max=0.66%
7 longitudinal cracks
max. width 7cm
max. length 300m
max=0.1%
no abnormal
max=1.26%
no abnormal, large
settlement and cracks in the
U/S uncompacted fill
Shuisheh Dam - Longitudinal crack at dam crest
Tousheh Dam - Crack at uncompacted fill
Liyutan Dam - Transversal crack near left abutment
760
Shuisheh Dam
EL. 751.51
EL. 748.48
750
0.7
4
740
1
4
730
1
1
1
U/S shell
EL. 748.48
0.3
D/S shell
core
720
RC wall
710
50
100
150
200
250
700
(a) Calculated acceleration at Shuisheh
dam crest , amax = 0.705 g
0
Calculated Dynamic Responses
-700
0
10
20
30
40
50
60
70
80
90
100
Time (sec)
amax=0.705
amax=0.805
0.6
0.7
0.8
0.7 0.8
(b) Distribution of amax
0.7
0.7
0.7
0.7
0.5
0.4
Acceleration (gal)
Acceleration (gal)
0
0.6
0.5
Unit：g
500
Input motion for Shuisheh dam
amax = 0.46g
Input Motion
0
-500
0
10
20
30
40
50
Time (sec)
60
70
80
90
100
0.4
Shuisheh Dam
Max. crest settlement : 23cm (20cm)
Max. settlement : 48cm
Max. bulge : 9cm
▽
0
2
4
6
8
10
m
Deformation scale
Max. settlement : 8cm (9~13cm)
Max. bulge : 1cm (0~1cm)
(Note : number in parenthesis denotes actual observed value after earthquake)
Estimated Dam Deformation
760
Tousheh Dam
EL.750.5
EL. 748.5
750
3
3
1
740
1
Fill
1
1
Shell
730
3
0.5
1
Core
Lake Deposite
1
Shell
RC wall
720
710
0
50
100
Acceleration (g)
(a) Calculated acceleration at Tousheh
dam crest, amax=0.926g
150
200
250
300
Calculated Dynamic
Responses
Time (sec)
amax=0.926
0.7
0.6
0.6
0.7 0.8 0.9
0.9 0.8
0.7
0.7
0.6
0.6
0.5
0.6
0.7
0.7
0.6
0.5
0.4
0.4
0.4
0.4
Unit：g
Input Motion
Acceleration (g)
0.4 0.4
0.6
Input motion for Tousheh dam
amax=0.51g
0.4
0.2
0
-0.2
-0.4
-0.6
0
10
20
30
40
Time (sec)
50
60
70
80
Tousheh Dam
Max. settlement 23cm(20cm)
Max. settlement 64cm
Deformation scale
0.0 1.0 2.0 3.0 4.0 5.0 (m)
(Note : number in parenthesis denotes actual observed value after earthquake)
Estimated Dam Deformation
Liyutan Dam
Calculated
0
10
20
30
40
Time (sec)
50
60
70
Acceleration(g)
(a) Calculated acceleration at Liyutan
dam crest, amax = 0.251g
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
80
(b) Dam crest, amax = 0.250g
Actual Records
0
10
20
30
40
Time (sec)
50
60
70
(b) Distribution of amax
amax=0.251 (0.250)
300
amax=0.197 (0.200)
280
260
240
220
200
0
50
100
150
200
250
300
350
400
450
(Note : number in parenthesis denotes actual recorded value) Unit : g
0.2
Input Motion
(Actual Records)
Acceleration (g)
Acceleration(g)
Calculated and Recorded Dynamic Responses
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
(a) Rock base, amax = 0.127g
0.1
0
-0.1
-0.2
0
10
20
30
40
Time (sec)
50
60
70
80
500
80
Liyutan Dam
1A,1B : Impervious core
2
: D/S shell
3A
: U/S semi-pervious shell
3B
: U/S pervious shell
6
: Misc. fill
320
300
EL. 306.
3
1
280
EL. 280.
3A
2.5
EL. 270.
260
1
EL. 250.
2
240
3B
0.5
1
3B
220
1
3B
1
1
1B
2
0.5
6
EL. 220.
1A
200
0
100
320
0
300
200
300
400
5
Displacement scale (m)
crest settlement =8~11cm(5~8cm)
max. settlement : 17cm(0~10cm)
280
500
Settlement : -1.7~7.7cm
(1~5cm)
260
240
220
200
0
20
40
60
80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500
Estimated Dam Deformation
1
100
0.8
10
Dam crest settlement (%)
amax at dam crest (g)
Relationship between Case Records and
Analysis Results
0.6
0.4
ERTH (measured)
ERRK (measured)
HYDF (measured)
ERTH (calculated)
HYDF (calculated)
0.2
1
0.1
ERTH (measured)
ERRK (measured)
HYDF (measured)
ERTH (calculated)
HYDF (calculated)
0.01
0.001
0
0
0.1
0.2
0.3
0.4
amax at dam site (g)
0.5
0.6
0
0.1
0.2
0.3
0.4
0.5
amax at dam site (g)
0.6
0.7
0.8