Project:  Residual Strength of Liquefied Soil

PI(s):  Steve Kramer

Sponsor:  PEER-NSF, WSDOT

Objective:  To develop more reliable procedures for estimating the residual shear strength of liquefied soils.

Research Approach:  The residual strength of liquefied soil is one of the most important problems in contemporary geotechnical earthquake engineering practice. Estimation of residual strength is generally accomplished by one of two methods - laboratory testing or empirical correlation based on case history analysis. Current laboratory testing techniques suffer from lack of stress and strain uniformity and/or limited strain capabilities. A ring simple shear device (RSSD) has been developed that allows cohesionless soil to be tested under uniform stress and strain conditions to virtually limitless strain levels. The RSSD is being used to evaluate the residual strength behavior of several sands with different gradations, particle angularities, and fines contents. Current empirical correlation techniques show significant scatter, primarily due to the significant uncertainties associated with the inputs to the stability analyses from which residual strengths are backcalculated. In this project, case histories will be re-evaluated with due consideration of uncertainties in input parameters to allow probabilistic estimation of residual strength.

For more information send E-Mail to: kramer@u.washington.edu