The Use of MASW in the Assessment of Soil Liquefaction Potential - PowerPoint PPT Presentation

1 / 28
About This Presentation
Title:

The Use of MASW in the Assessment of Soil Liquefaction Potential

Description:

The Use of MASW in the Assessment of Soil Liquefaction Potential Chih-Ping Lin C-C Chang, I-L Chen, T-S Chang National Chiao Tung University, Taiwan – PowerPoint PPT presentation

Number of Views:348
Avg rating:3.0/5.0
Slides: 29
Provided by: 6649602
Category:

less

Transcript and Presenter's Notes

Title: The Use of MASW in the Assessment of Soil Liquefaction Potential


1
The Use of MASW in the Assessment of Soil
Liquefaction Potential
  • Chih-Ping Lin
  • C-C Chang, I-L Chen, T-S Chang
  • National Chiao Tung University, Taiwan
  • November 4, 2003

2
Outline
  1. Backgrounds
  2. Multi-channel Analysis of Surface Wave
  3. Verification Case
  4. 2-D Imaging of Liquefaction Potential
  5. Summary

3
Acknowledgement
  • Funding for this research was provided by the
    National Science Council and Institute of
    Planning Hydraulic Research.

4
Field Tests for assessing liquefaction potential
  • Standard Penetration test(SPT)
  • Cone Penetration Test(CPT)
  • Shear Wave Velocity Measurements (SWV)
  • Vs vs. Liquefaction resistance
  • Effects of large particles minor
  • Non-invasive method can be used
  • Can be measured in the lab and in-situ
  • Directly related to Gmax required for site
    response

1
2
3
4
5
5
Shear Wave Velocity Measurements
  • Cross-hole
  • Down hole
  • Seismic cone
  • Suspension PS-logger
  • Surface wave method
  • Non-invasive
  • Efficient
  • Cost effective

1
2
3
4
5
6
Basic Principle of Surface Wave Method
1
Frequency component
Geophones
2
VS
VS1
3
4
VS2
5
VS3
z
Dispersion curve
Field Testing
V
Dispersion analysis
Inversion
f
7
Surface Wave Methods
  • Two-station methods
  • Steady-state Rayleigh wave method (SSRW)
  • Spectral analysis of surface wave (SASW)
  • Multi-station Method
  • Phase-offset regression (MSASW)
  • Multi-station wavefield transformation of surface
    wave (MWTSW)

1
2
3
4
5
8
SASW Method
1
Df
2
3
4
5
Unwrapping in f domain
Df
v
f
f
9
Multi-station Data Acquisition
1
u(tm,xn)
Measurement
f 10, v 200 m/s
2
3
4
5
t
t-x domain
x
10
MSASW Method
1
DFT w.r.t. time domain
2
3
4
5
f
f
R2
x
11
MWTSW Method
k
1
DSFT w.r.t. space domain
2
3
t-x domain
4
5
f-x domain
f-k domain
f-v domain
12
Multi-station Analysis of Surface Wave
1
0
1
N-2
N-1
2
x0
Dx
L
3
Source
4
Geophone
5
13
Multi-station Wavefield Transform
1
2
3
4
f-k
f-p
5
f-l
f-v
14
Verification Case - Site
1
2
3
4
5
15
Seismic Equipment
1
2
3
4
5
16
Verification Case Field Testing
1
2
3
4
5
17
Verification Case Dispersion AnalysisDx 0.5
m, L 11.5 m
1
2
3
4
5
18
Verification Case Dispersion AnalysisDx 1 m,
L 23 m
1
2
3
4
5
19
Verification Case Dispersion AnalysisDx 1 m,
L 23 m
1
2
3
4
5
20
Verification Case Inverse Analysis
1
2
3
4
5
21
Verification CaseVs and FS against liquefaction
1
2
3
4
5
22
Surface Wave Seismic Imaging
1
2
3
4
5
23
Surface Wave Seismic Imaging
1
2
3
4
5
24
Surface Wave Seismic Imaging
1
2
3
4
5
25
Andrus and Stokoe (2000)
1
2
3
4
5
26
Summary
  • Advantages of MASW
  • Field testing simple efficient
  • Multi-station redundancy
  • Automation site quality control
  • Robustness dispersion curve visualized
  • 2-D imaging

1
2
3
4
5
27
Summary
  • The results show that the MASW
  • efficient, cost effective, and non-invasive
  • useful in gravelly soils
  • effective for first look or investigation of
    lateral variations
  • Further Research
  • Lateral resolution
  • Inversion and vertical resolution

1
2
3
4
5
28
Thank You!
  • Chih-Ping Lin
  • Geotechnical Engineering Group
  • National Chiao Tung University
Write a Comment
User Comments (0)
About PowerShow.com