Location

San Diego, California

Session Start Date

3-26-2001

Session End Date

3-31-2001

Abstract

For most ground response analyses, the shear modulus is an important parameter to be determined and it has to be measured over a large strain range, so as to characterise the soil behavior under various loading conditions. Laboratory measurement of shear modulus covers a limited strain range depending on the test method. The main difficulty lies in the determination of the shear modulus at very small strains. In this respect, geophysical methods are more attractive. One of these test methods, which uses a continuous surface wave, is used to obtain the shear modulus profile at two sites in Singapore. The Continuous Surface Wave System (CSWS) is a nonintrusive field geophysical test consisting of a vibrator source and several receiver geophones connected to a computer system. The computer collects and analyses the field data, and provides a shear modulus profile at the test site. Conclusions from the field tests support published literature that such field seismic tests are capable of measuring the low-strain shear modulus well. The interpretation of field test data in the absence of specific stratigraphic information can pose some difficulties. An important part in interpreting continuous surface wave measurement data is in the selection of a suitable inversion tool so as to derive the correct shear modulus profile for the site under consideration. A finite element approach (using LS DYNA) is investigated for inversion of field test data. Data obtained from S-wave cross-hole survey are also compared with field tests data obtained using CSWS.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Meeting Name

Fourth Conference

Publisher

University of Missouri--Rolla

Publication Date

3-26-2001

Document Version

Final Version

Rights

© 2001 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

Share

COinS
 
Mar 26th, 12:00 AM Mar 31st, 12:00 AM

Measurement of Shear Modulus Profile Using a Continuous Surface Wave Measurement System

San Diego, California

For most ground response analyses, the shear modulus is an important parameter to be determined and it has to be measured over a large strain range, so as to characterise the soil behavior under various loading conditions. Laboratory measurement of shear modulus covers a limited strain range depending on the test method. The main difficulty lies in the determination of the shear modulus at very small strains. In this respect, geophysical methods are more attractive. One of these test methods, which uses a continuous surface wave, is used to obtain the shear modulus profile at two sites in Singapore. The Continuous Surface Wave System (CSWS) is a nonintrusive field geophysical test consisting of a vibrator source and several receiver geophones connected to a computer system. The computer collects and analyses the field data, and provides a shear modulus profile at the test site. Conclusions from the field tests support published literature that such field seismic tests are capable of measuring the low-strain shear modulus well. The interpretation of field test data in the absence of specific stratigraphic information can pose some difficulties. An important part in interpreting continuous surface wave measurement data is in the selection of a suitable inversion tool so as to derive the correct shear modulus profile for the site under consideration. A finite element approach (using LS DYNA) is investigated for inversion of field test data. Data obtained from S-wave cross-hole survey are also compared with field tests data obtained using CSWS.