A hybrid modelling of soil–structure interaction problems for deeply embedded structures in A multilayered medium

Dynamic response of deeply embedded structures, such as underground tunnels and deep foundations, in a multilayered elastic half‐space are analysed when the structure is excited by a plane P or SV wave propagating at some angle. The scattered field is represented by the sum of three Green's functions, corresponding to two oscillating forces and one oscillating moment at the centroid position of the buried structure. The amplitudes of these two forces and one moment are a priori unknown and are obtained by satisfying displacement and stress continuity conditions across the near‐field/far‐field boundary. The distinguishing feature of this technique from direct or indirect boundary integral techniques is that in these techniques a distribution of sources of unknown amplitude are considered at the near‐field/far‐field boundary, and a large number of sources are needed for different combinations of source‐receiver arrangements. But in this technique the sources of unknown amplitude are placed at the location of the structure, not at the near‐field/far‐field boundary and, using the Saint Venant's principle, the scattered field is modelled. Thus, the number of sources required is reduced to only three. Two example problems are solved. The first one is for a deeply embedded footing in a three‐layer soil mass and the second one is for a rectangular tunnel in a two‐layer soil mass.