Abstract:In order to study the deformation and dynamic characteristics of foundation soil under impact loads, Mohr-Coulomb model, rigid body impact loads, non-linear large deformation finite element method and ALE adaptive technology in ABAQUS finite element program are used to analyze the deformation, stress and acceleration. Comparing with the actual monitoring data, the results indicate that the calculated results acquired in the analysis are close to the actual data,which verifies the rationality of the model.Based on the model, the effects of different energy levels, different impact times and different elastic modulus of soil on the deformation, stress, velocity and acceleration of foundation soil are studied. The results show :1) there is a linear relationship between tamping energy deformation and deformation elastic modulus; 2) under impact loads, the soil presents elastic-plastic deformation to elastic deformation and gradually recovers only residual plastic settlement deformation; 3) impact energy transfers downward and decreases continuously from 40~45°. In the construction process, it is advisable to determine the compaction spacing reasonably and to tamp the soil in dislocation in order to ensure the effective treatment of the soil mass. 4) The vertical stress time history curve is approximately triangular, and only one peak stress appears.