考虑地基与基础的相互作用,运用Biot波动方程理论,研究了饱和地基表面有质量的刚性圆形基础在入射Rayleigh波作用下的摇摆振动问题。将饱和地基中的总波场分解为自由波场、刚体辐射波场及刚体散射波场,从而考虑基础对Rayleigh波的散射。采用Hankel变换求解土体控制方程,结合基础摇摆振动的混合边值条件以及Rayleigh波的动力作用获得基础摇摆振动振幅的表达式。计算结果分析了泊松比、基础质量、透水条件、土体渗透系数等对基础摇摆振动的影响。研究结果表明,与弹性介质相比,饱和地基中孔隙水的存在减弱了基础的摇摆振动,其作用效果与土体渗透系数及地基表面排水条件密切相关。
Considering the interaction between soil and foundation, an investigation is put into rocking vibrations of a rigid circular foundation on the poroelastic soil excited by incident Rayleigh waves based on Biot's dynamic theory. The free field, rigid-body radiation field and rigid-body scattering field are introduced in order to consider the scattering phenomena caused by the existence of the foundation. Using the Hankel integral transforms, the governing equations of the soil are solved. Combining with the mixed boundary-value condition at the interface between the soil and the foundation, expression of the rocking dynamic amplitude of the foundation under the action of the Rayleigh waves is obtained. Influences of the Poisson ratio, the mass of foundation, the boundary drainage, the permeability of soil on rocking vibrations of the foundation are determined through numerical calculation. Computed results show that pore water in the soil has weakening effect on rocking vibrations comparing with that in elastic half-space. And the weakening effect depends upon the boundary drainage and permeability of soil.