The double yield surface elastic-plasticity constitutive model and the loading-unloading criterion are considered in this paper. The deformation of soil skeleton and the pore water pressure are also analyzed as the coupling variable. The procedure of single-point and single-time impacting is simulated by using the finite dynamic element program DCFEM which is suited to stratified soft soil foundation. The results of calculation show that the peak stress

peak pore water pressure and peak deformation are delay with the increasing of depth and radial distance to center of the hammer bottom. The stress wave transmits in ground according to erect elliptical spherical surface; and its attenuation is very quick. The consistency between the computation results and the data measured in-situ is obtained. The effective means simulating in-situ project of soft clay foundation which was treated by dynamic consolidation and drainage method is provided.