NUMERICAL ANALYSIS OF LIQUEFACTION PHENOMENON BY USING UBC3D-PLM CONSTITUTIVE MODEL

Abstract

This research is considering of numerical analysis of liquefaction phenomenon by using UBC3D-PLM constitutive model. Liquefaction is a phenomenon in which the strength and stiffness of a soil is reduced by earthquake shaking or other rapid loading. Liquefaction occurs in saturated soils, that is, soils in which the space between individual particles is completely filled with water. This water exerts a pressure on the soil particles that influences how tightly the particles themselves are pressed together. Prior to an earthquake, the water pressure is relatively low. However, earthquake shaking can cause the water pressure to increase to the point where the soil particles can readily move with respect to each other. The UBC3D-PLM is one of the most commonly used constitutive models for liquefaction problems in practice. Even though it is an advanced model, it is relatively simple to apply, since it has a reasonable number of parameters that can be extracted from laboratory or in situ tests. The model was initially developed for sand-like soils having the potential for liquefaction under seismic loading. The UBC3D-PLM model has been developed by Tsegayce (2010) and implemented as a user defined model in PLAXIS. In this research, the capability of this model is considered by using PLAXIS software. The real data of El Centro earthquake 1940, Imperial Valley earthquake 1979 and Upland earthquake 1990 were used. The results of the simulation have shown resembling trend of the UBC3D-PLM and HSSMALL models. This research compare between the results which get after earthquake on liquefied sand and strong layer (coarse sand).