Location

San Diego, California

Session Start Date

5-24-2010

Session End Date

5-29-2010

Abstract

Sensitivity describes the effect of soil disturbance/remoulding on shear strength. Cyclic stresses during seismic events may lead to varying levels of disturbance and remoulding of brittle sensitive clays. The Canadian Foundation Engineering Manual (CFEM) recommends site-specific evaluation of the seismic hazard, including site response analysis, for sites that have quick or highly sensitive clays. Different levels of soil sensitivity have been shown in different versions of CFEM and their errata. The current manual CFEM (2006) classifies clay as highly sensitive if its sensitivity is greater than 40 (classified as Class F soil). However, there is considerable variation within the literature with respect to descriptions of sensitivity and more importantly, the related seismic risks that different soil states represent. This can have a significant impact on determination of the appropriate seismic forces on supported structures according to the seismic provisions of the current National Building Code of Canada, NBCC (2005). This paper reviews the different methods used to evaluate soil sensitivity and the sensitivity classifications in the literature. Based on this review, suggestions are provided for improvements of this approach to seismic design.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

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

Meeting Name

Fifth Conference

Publisher

Missouri University of Science and Technology

Publication Date

5-24-2010

Document Version

Final Version

Rights

© 2010 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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May 24th, 12:00 AM May 29th, 12:00 AM

Review of Available Methods for Evaluation of Soil Sensitivity for Seismic Design

San Diego, California

Sensitivity describes the effect of soil disturbance/remoulding on shear strength. Cyclic stresses during seismic events may lead to varying levels of disturbance and remoulding of brittle sensitive clays. The Canadian Foundation Engineering Manual (CFEM) recommends site-specific evaluation of the seismic hazard, including site response analysis, for sites that have quick or highly sensitive clays. Different levels of soil sensitivity have been shown in different versions of CFEM and their errata. The current manual CFEM (2006) classifies clay as highly sensitive if its sensitivity is greater than 40 (classified as Class F soil). However, there is considerable variation within the literature with respect to descriptions of sensitivity and more importantly, the related seismic risks that different soil states represent. This can have a significant impact on determination of the appropriate seismic forces on supported structures according to the seismic provisions of the current National Building Code of Canada, NBCC (2005). This paper reviews the different methods used to evaluate soil sensitivity and the sensitivity classifications in the literature. Based on this review, suggestions are provided for improvements of this approach to seismic design.