Soil-pile interaction in inhomogeneous transversely isotropic media

Through a rigorous mathematical formulation, this paper considers the axisymmetric interaction analysis of a thin-walled cylindrical pile with finite length embedded in an exponentially graded transversely isotropic half-space under axial loads at the top of pile. The action of pile to the embedding medium is represented with axial and radial ring loads and the relevant set of Green's functions for the pile and semi-infinite soil medium has been developed. By satisfying the compatibility conditions between the two interacting media, the interaction analysis is shown to be reducible to a pair of Fredholm integral equations. Due to the complex nature of mathematical formulations and the intrinsic singularity of stress transfer, the analytical solution of obtained boundary integral equations is not possible and a suitable numerical scheme has been developed. By means of adaptive gradient shape functions which are capable of smoothly capturing regular and singular solutions, the given Fredholm integral equations are discretized in the common boundary of interacting media and solved numerically for the interfacial stress components. The numerical procedure is verified through comparisons with previous studies and the effect of inhomogeneity of soil layer on different responses of the interaction process is discussed by presenting several numerical results. (C) 2019 Production and hosting by Elsevier B. V. on behalf of The Japanese Geotechnical Society.