Through the research of the natural vibration properties,the characteristics of seismic response,the different computation patterns affecting to the seismic response and the influence of the subgrade spring stiffness on natural vibration property,it provides a reference for the similar structural design.

According to the subgrade spring soil problems occurred in Jiangsu Haimen Binhai New Area Road construction, there were 4 treatment methods analyzed in the paper including their respective advantages and disadvantages.

This paper introduces the modeling of the vertical pile response from time-domain wave equation analysis with the soil spring constants derived from t-z and Q-z curves and the time-dependent damping coefficients obtained from the dynamic impedance functions.

A finite element analysis method is adopted to conduct numerical simulation on single pile under lateral load test,the effects of surrounding soil are replaced by soil springs and a new method is put forward for soil spring stiffness derived from test data.