Analysis of rocking vibrations of a foundation on saturated soil excited by Rayleigh waves

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.