Based on K.Terzaghi’s soil mechanics model and taken account of soil dynamic nonlinear constitutive relation
soil shear dliatancy
rigidity degradation
hysteresis and water-soil relative motion
multi-phased medium dynamics theory is used to analyze the wave propagation and dynamic response of sand layers under water
and an artificial boundary condition is analyzed to simulate the wave propagation in pore medium. A set of dynamic equations of soil layers under water are established
and the equations are discreted to be used to analyze the earthquake engineering problem of soil under water
a direct differential method is suggested to calculate the water pressure and porewater pressure and to study the sand seismic liquefaction under water.