Assessment of liquefaction of sandy deposits during an earthquake is an important item in the design of port and airport facilities. A numerical analysis based on a finite element method is a useful tool for the foundation design considering the effect of
liquefaction on the structure. Most of the numerical programs do not consider the pore water pressure dissipation from soils during seismic loading. A numerical model for liquefaction analysis considering the dissipation of pore water pressure is newly
developed. This paper describes the numerical model and its application for the simulation of liquefied ground in actual earthquakes. The effect of the saturation ratio of the pore water on liquefaction is also analyzed by the program. The results show that the program can simulate the ground response to the earthquake and
calculate the subsidence of ground due to the dissipation of pore water pressure. The results of the effect of the saturation ratio show that the unsaturated ground with the saturation ratio of 99.8% (Skempton’s B-value=0.8) has the same liquefaction potential as the saturated ground.