A cyclic elasto-plastic model for sand and its application to liquefaction analysis

The aim of the present paper is to present a cyclic elasto-plastic constitutive model for sand and its application to effective stress based fully coupled liquefaction analysis. Some of the authors proposed a cyclic elasto-plastic model for sand based on the non-linear kinematical hardening theory considering a strain dependency of plastic modulus (Oka et al. 1999). The proposed model has been applied to the liquefaction analysis, in particular, after the 1995 Hyogoken Nanbu Earthquake in Japan. Through the application of the model, it has been found that the some modification or simplification of the model is effective for the application when there does not exist enough data to determine the soil parameters, and the more information on the method of determination of soil parameters is necessary. In the present paper, firstly, the outline of the model for sand is described and secondly the possible modification of the strain dependency of plastic modulus is proposed Finally, we will show the numerical application of the model for liquefaction analysis of ground and ground-structure system.