Abstract：In order to reasonably interpret pile integrity test，the model of viscoelastic pile with variable sections in layered soils is established. When the pile is subjected to exciting force at its top，the viscoelastic supporting at its tip is taken into account . By means of Laplace transform and matrix theory，the semi-analytical solution of pile-soil systerm is derived. Further，with the help of the convolution theorem and inverse Fourier transform，a semi-analytical solution on the velocity response of pile top to semi-sine impulse exciting is obtained. Later，by numerical methods，the influences of layered soils and pile parameters on velocity response of pile top are simulated，and several significant conclusions for pile integrity test are drawn.
