Rocking vibrations of a rigid embedded foundation in a poroelastic half‐space

Abstract

SUMMARYThis paper presents an analysis of the rocking vibrations of a rigid cylindrical foundation embedded in poroelastic soil. The foundation is subjected to time-harmonic rocking excitation and is perfectly bonded to the surrounding soil. The soil underlying the foundation base is represented by a homogeneous poroelastic half-space, whereas the soil along the side of the foundation is modeled as an independent poroelastic stratum composed of a series of infinitesimally thin layers. The behavior of the soil is governed by Biot's poroelastodynamic theory. The contact surface between the foundation base and the poroelastic soil is assumed to be smooth and either fully permeable or impermeable. The dynamic interaction problem is solved by employing a simplified analytical method. Some numerical results for the nondimensional rocking dynamic impedance and nondimensional angular displacement amplitude of the foundation are presented to show the effect of nondimensional frequency of excitation, poroelastic material parameters, hydraulic boundary condition, depth ratio and mass ratio of the foundation.

An analytical solution for the horizontal vibration behavior of a cylindrical rigid foundation in poroelastic soil layer

“…[4][5][6] To overcome this deficiency, Senjuntichai et al 13 used the Biot's poroelastic theory and established the governing equations of the cylindrical rigid foundation in poroelastic half-space subjected to vertical loads, where the dual integral equations were solved by iterative approach. Similarly, Cai and his coworkers [14][15][16][17] provided a simplified analytical frame to obtain the compliance coefficient of a rigid foundation partially embedded in soil, which can be used for the vertical and rocking vibrations of foundation problem. However, in most practical situations (for instance, offshore wind turbines and port pier projects), large size cylindrical foundations in the horizontal direction often encounter strong dynamic loads.…”

“…Although the horizontal dynamic response factor of the rigid, circular embedded foundation was presented by Zheng et al., 18 but this work was limited to the case of poroelastic half‐space medium. A series of numerical results showed the stand waves induced by the external vibrations can reflect and refract in the finite‐layered media, and the deformation and stress field of the soil underneath the foundation is clearly different from that of half‐space soil 14,16 . Consequently, the bearing behaviors of the embedded foundations in soil layer of finite thickness excited by horizontal dynamic load deserve to gain extensive attention.…”