饱和地基中埋置基础摇摆振动的动力放大系数

基于Biot动力控制方程,研究均质饱和半空间中埋置刚性圆柱基础在摇摆简谐力矩作用下的振动特性.土与基础在四周及基底保持完全黏着接触,相互之间无滑移.利用一种简化的解析方法求解相应的动力响应问题,并给出埋置基础摇摆振动时的动力放大系数随量纲一激振频率的变化曲线.为验证本文结果的正确性,将地基退化为单相弹性介质,计算相应的动力放大系数曲线,并与已有的结果进行对比.可以看出,量纲一激振频率、基础埋深比、基础质量比和渗透系数均对饱和地基中埋置基础摇摆振动的动力放大系数有很大的影响.

Dynamic response factor for rocking vibration of embedded foundation in saturated soil

The rocking vibration of a rigid cylindrical foundation embedded in a homogeneous saturated half space was studied based on Biot’s theory of poroelastodynamics. The foundation was subjected to the time harmonic rocking excitation and was perfectly bonded to the surrounding soil. The dynamic interaction problem was solved by employing an approximate analytical method. The analysis was performed in the frequency domain. The accuracy of the present solution was verified by degenerating the saturated soil to elastic soil and compared with the existed solutions for an ideal elastic soil. Numerical results for dynamic response factor of embedded foundations indicate that the nondimensional frequency of excitation, the depth ratio of foundation, the mass ratio of the foundation and the soil permeability all have significant effect on the rocking vibration of embedded foundation in saturated soil.