横观各向同性层状场地的动力边界条件

 采用横观各向同性层状弹性体模拟场地土, 对该场地底部采用了三种不同的边界: 固定边界、阻尼边界及半空边界。推导了这三种边界条件的公式, 并且给出了它们进入离散化后的Rayleigh 波与Love 波的代数特征方程方法。然后, 计算了场地在三种边界条件下对垂直及水平简谐集中荷载的位移响应, 并与理论解进行了比较, 指出了它们的适用范围。

THE DYNAMIC BOUNDARYCONDITIONS OF TRANSVERSELY ISOTROPIC STRATIFIED MEDIA

The formulas of three dynamic boundary conditions of transversely isotropic stratified media are derived. And the methods how to combine them with the discretized algebraic eigenvalue equation for generalized Rayleigh and Love waves are also given. The dynamic responses of the media with these different boundary conditions to concentrative harmonic loads are evaluated and compared with the theoretical results. Through the comparison, it can be found that the responses of the media with damping and half space boundary conditions when the media are thick, are close to the theoretical ones. But for the fixed boundary condition, only the responses of upper soil layers are close to theoretical ones. The results near the bottom of soil layers are much different from those for damping and half space boundary conditions. According to the evaluation, the applicable ranges for these boundary conditions are suggested.