Abstract: Dynamic consolidation （heavy tamping） is one of recent methods for foundation, improvent. Up to the present time, this method still retains in experience accumula tion stage. This paper firstly introduces the new apparatus of dynamic coaolidation and its testing method and results. Secondly, by these laboratory parameters, stress, pore pressure and deformation in foundation after heavy tamping were obtained by three numerical methods. The calculated results were checked with those from field measurements. Finally, based on boundary element computation, a chart was plotted for design purpose of dynamic consolidation.