Location

San Diego, California

Session Start Date

5-24-2010

Session End Date

5-29-2010

Abstract

From the earliest studies of soil behavior under cyclic loading, it is found that the cyclic stress required for liquefaction onset is strongly affected by the relative density (Dr ) and initial effective overburden pressure of the soil. In this paper, relative state parameter index (ξR), which accounts for both relative density and effective stress, is used to evaluate the likelihood of liquefaction initiation in field condition. Two comprehensive databases of field case histories based on SPT and CPT are incorporated in the analyses. Logistic regression method is employed to derive a probabilistic expression that yields the probability of liquefaction initiation in terms of ξR. The most advantage of this expression is its consistency with both field SPT and CPT data. In addition, relative state parameter index has been evolved from dilatancy concept which has a reasonable consistency with liquefaction phenomenon. The boundary curve that obtains 20% likelihood of liquefaction initiation is found to be the most conservative boundary and is recommended as a deterministic ξR -based liquefaction criterion. Finally, a relationship is proposed to correlate liquefaction probability to the factor of safety against liquefaction triggering.

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

Probabilistic Evaluation of Field Liquefaction Potential Using Relative State Parameter Index (ξR)

San Diego, California

From the earliest studies of soil behavior under cyclic loading, it is found that the cyclic stress required for liquefaction onset is strongly affected by the relative density (Dr ) and initial effective overburden pressure of the soil. In this paper, relative state parameter index (ξR), which accounts for both relative density and effective stress, is used to evaluate the likelihood of liquefaction initiation in field condition. Two comprehensive databases of field case histories based on SPT and CPT are incorporated in the analyses. Logistic regression method is employed to derive a probabilistic expression that yields the probability of liquefaction initiation in terms of ξR. The most advantage of this expression is its consistency with both field SPT and CPT data. In addition, relative state parameter index has been evolved from dilatancy concept which has a reasonable consistency with liquefaction phenomenon. The boundary curve that obtains 20% likelihood of liquefaction initiation is found to be the most conservative boundary and is recommended as a deterministic ξR -based liquefaction criterion. Finally, a relationship is proposed to correlate liquefaction probability to the factor of safety against liquefaction triggering.