MODELING OF SEISMIC SLOPE BEHAVIOR WITH SHAKING TABLE TEST Meei-Ling Lin and Kuo-Lung Wang Department of Civil Engineering, National Taiwan University he Next Generation of Research on Earthquake-induced Landslides n International Conference in Commemoration of 10th Anniversary of the Chi-Chi Earthquake, 2009
43
Embed
MODELING OF SEISMIC SLOPE BEHAVIOR WITH SHAKING TABLE TEST Meei-Ling Lin and Kuo-Lung Wang Department of Civil Engineering, National Taiwan University.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
MODELING OF SEISMIC SLOPE BEHAVIOR WITH SHAKING TABLE TEST
Meei-Ling Lin and Kuo-Lung WangDepartment of Civil Engineering, National Taiwan University
The Next Generation of Research on Earthquake-induced LandslidesAn International Conference in Commemoration of 10th Anniversary of the Chi-Chi Earthquake, 2009
Outline
• Shaking table test
• Specimen preparation and law of similarity
• Test result
• Particle Image Velocimetry (PIV) analysis
• Displacement behavior
• Summary
Objectives
The initiation of landslide and the development of slip surface for landslides induced by earthquakesRun-out distance and slope recession caused by landslideIdentification of affected area of potentially unstable slope
4
Model Slope Shaking Table Test System calibration
100
440
120
50
177
AC7AC8
AC9
AC10
AC12,AC13
AC11
L1,L2
L3,L4
AC1,AC2
AC3,AC5
AC4,AC6
-0.4
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0 5 10 15 20 25
Time(sec)
Accce
lera
tio
n(g
)
m: 39838 kgk: 551.9kN/m c: 174.3 kN.sec/m
Insignificant amplification were found from accelerometer and LVDT measurements
Law of Similitude• Assumptions (Iai, 1989)
– soil skeleton is regarded as continuous medium– deformation is assumed to be small so that the equilibrium equation
remains the same before and after the deformation– the strain of the soil skeleton is small
• 8.9 Hz of loading frequency was applied for a scale factor of 20 based on 1-g, equivalent density, and strain conditions
Mass Density 1 Acceleration 1 Length λ
Force λ 3 Shear Wave Velocity λ 1/2 Stress λ
Stiffness λ 2 Time λ 1/2 Strain 1
Modulus λ Frequency λ -1/2 EI λ 5
Meymand(1998)
33
3
3
1
mm
pp
mm
pp
m
p
V
V
am
am
F
F
Model Granular Slope Shaking Table Test Specimen Preparation
• Acceleration by accelerometers• Image video recordings, particle displacement, particle velocity • Mapping of slip and deposit surface, mapping of run-out and
• Surface change detection via particle image velocimetry (PIV)– Particle moving direction and
magnitude– The initiation of slope surface slip
• Identification of slip initiation from acceleration history– The initiation of subsurface slope
slip
Specimen C
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0 5 10 15 20 25 30 35
Time (sec)
Acc
ele
ratio
n (
g)
Table_achive_EW(g)
AC12(g)
crest
Test Result – Video Recording and PIV Analysis
Processed with PIVview2C
Note: play video files
CrestCrest
Test Result – the Initiation of Slip
Specimen Loading amplitude (g) from PIV
Loading amplitude (g)/Time (sec) from acceleration history
A 0.11 0.35g, 11sec
B N/A 0.28g, 4.04sec
C 0.09 0.32g, 22.04sec
D 0.15 0.24g, 25.2sec
E N/A 0.24g, 9.85sec
Initiation of surface slipInitiation of subsurface slip
Runt-out and Recessional Distances
Specimen A
Specimen B
Specimen C
CrestToe
unit: cm
Run-out and Recessional Distances
Specimen D
Specimen E
CrestToe
unit: cm
Relationship Between Distances and Loadings
Specimen Unit weight(kN/m3)
Maximum Loading Amplitude(H, V) in g
Loading Period(sec)
Crest Displacement
Max/Min
(cm)
Toe Displacement
Max/Min(cm)
A 15.3 1st - (0.35, 0.00)
2nd - (0.58, 0.00)
1st - 21 sec
2nd - 11 sec
43.5/22.1 28.6/19.1
B 15.8 1st - (0.28, 0.00)
2nd - (0.43, 0.00)
1st - 14 sec
2nd - 14 sec
12.7/8.6 18.5/10.3
C 15.8 1st - (0.34, 0.08)
2nd - (0.41, 0.20)
1st - 32 sec
2nd - 32 sec
26.7/21.8 45.6/22.6
D 15.5 1st - (0.26, 0.10)
2nd - (0.32, 0.19)
1st - 32 sec
2nd - 32 sec
12.6/8.0 17.2/6.3
E 15.5 1st - (0.38, 0.12)
2nd - (0.38, 0.12)
1st - 16 sec
2nd - 16 sec
11.4/7.7 15.8/5.7
Values after prolong loading sequence
Comparing specimens (A, B) and (C, D) Recessional and run-out distance increased with increasing maximum loading amplitudeThe set of data with larger displacement were subjected to higher vertical loading coupled with higher horizontal loading
Comparing specimens (B, C)Recessional and run-out distance increased with additional vertical loading amplitude
Comparing specimens (D, E) and (C, E)Higher vertical loading resulted in higher recessional and run-out distances
0
5
10
15
20
25
30
35
40
45
50
0.3 0.35 0.4 0.45 0.5 0.55 0.6
Maximun loading amplitude (g)
Max
imum
dist
ance
(cm
)
RecessionalRun-out
0
5
10
15
20
25
0.3 0.35 0.4 0.45 0.5 0.55 0.6
Maximum loading amplitude (g)
Min
imum
dist
ance
(cm
)
RecessionalRun-out
Maximum distances
Minimum distances
The Relationship Between Crest Recession and Toe Run-out versus Loading Amplitude