Abstract:Testing results of piles under low strain integrity are normally interpreted using one-dimensional stress wave theory. While one-dimensional stress wave theory is acceptable for pile-driving analysis,the responses of piles integrity tests can not be adequately simulated when the hammer and the incident wave length are small in relation to the diameter of the pile. Extensive parametric studies are performed using one-dimensional and three-dimensional(axisymmetrical) wave equation models respectively. Considering the calculation precision and efficiency,the axisymmetrical system of COMSOL Multiphysics is used to simulate the process of pile¢s dynamic test. The main three-dimensional effect lies in the oscillating degrees of velocity curves and the time of reflected wave. Under the conditions of different hammers,wave lengths and pile diameters,the three-dimensional dynamic effect is analyzed. Moreover,some suggestions about how to avoid three-dimensional dynamic effect are put forward.