NONLINEAR SEISMIC RESPONSE OF LOOSE SAND DEPOSITS.

Modelling of liquefaction phenomenon in soils subjected to an earthquake loading has received considerable attention in recent years. This is due to increasing demands imposed on safety of important engineering structures supported by soil media. For such structures the determination of failure conditions requires a study of liquefaction potential of the soil beneath the foundation. In this paper liquefaction potential of a loose sand layer subjected to earthquake loading is evaluated. The analysis is performed by using the finite element technique incorporating the equations of dynamics of saturated porous elastoplastic media. The soil response is modelled by using a combined isotropickinematic hardening rule, as recently proposed by the first author and H. B. Poorooshasb. The constitutive concept is based on the theory of bounding surface plasticity incorporating a non-associated flow rule and the idea of reflected plastic potential.