Through the detailed analysis of cavity expansion theory , strain path method and finite element theory applied in jacked pile , some deficiencies are put forward . according to the analysis , some main original work are made . firstly , on the basis of strain path method ( spm ) , closed - form analytical expressions of displacement fields caused by the installation of jacked pile are obtained in small strains 本文首先详尽地分析了圆孔扩张理论、应变路径理论、有限元理论在静压桩挤土效应方面存在的不足，并在此基础上做了如下工作： 1 、基于spm法的理论基础，在小应变假定情况下，推导了静压单桩周围土体位移场的解析解。
Thus the resistance factor and vibration modes of the soil layer are obtained and used to analysis the pile response . by considering the interaction between the soil layer and the pile with boundary condition of continuity of displacement and equilibrium of force at the interface of soil layer and pile , the dynamic equilibrium equation of pile is solved and an analytical solution for the pile response in frequency domain is yielded , which is used to define complex stiffness and mobility at the level of the pile head . based on the convolution theorem and inverse fourier transform , a semi - analytical solution of velocity response in time - domain subjected to a semi - sine exciting force is given 首先通过引入势函数方法对土体位移进行分解，从而将土体动力平衡方程解耦，求解得到了土层的振动模态和阻抗因子，然后利用该解以小应变条件下桩土接触面上力平衡和位移连续条件来考虑桩土耦合作用，求解桩的动力平衡方程，得到了桩顶的频域响应解析解、复刚度和速度导纳，利用卷积定理和傅里叶逆变换，求得了半正弦脉冲激振力作用下桩顶速度时域响应半解析解。
