土-桩-结构系统运动方程的求解方法

土－结构动力相互作用分析的子结构法中，土－结构系统运动方程的刚度矩阵和阻尼矩阵与频率相关。工程中通常采用系统的基本频率来计算地基的动力阻抗以简化运动方程的求解。对于土－桩－结构系统，本文提出一种时域中的精确解法来考察这种近似解法的有效性。

Solution for Motion Equations of Soil pile structure Systems

In the sub structure technique of dynamic soil structure interaction analysis,the frequency dependence of the impedance of soil results in a fact that the stiffness matrices and the damping matrices of the motion equations of soil structure systems are frequency dependent.In engineering practice,the fundamental frequency of the system is usually adopted to calculate the dynamic impedance of soil so as to simplify the solving of the motion equations.For the soil pile structure systems,an exact solution in time domain is developed to examine the validity of this approximate solution.The study shows that this approximate solution will yield relatively great errors in many cases.