Numerical computation of axisymmetric problems in low strain integrity tests on piles

A computing model for the transient vibration of soil-pile system was presented.The dynamic response of an intact pile impacted by transient axial impulse was computed by use of the finite difference method,and the difference between 3D(axisymmetric) and 1D axial velocity responses at the pile top was compared and analyzed.It was shown that the 3D effect was also related to the ratio of hammer radius to pile radius and shear velocity of the soil around the pile.The best position of receiver is 0.55R(R was pile radius) from the pile center.The wave snapshots at different time,which gave a visual interpretation of propagation of wave in the pile,were obtained.