Analysis of Embedded Foundations by Substructure‐Deletion Method

Abstract

An alternative formulation of the substructure‐deletion method for the dynamic analysis of three‐dimensional embedded foundations of arbitrary shape subjected to applied external forces and to incoming seismic waves is presented. The analysis is performed in the frequency domain, and the foundations are assumed to be rigid and embedded in a homogeneous viscoelastic half‐space, with welded contact along the embedded surface. This new formulation of the substructure‐deletion method is characterized by a boundary‐integral approach for the analysis of the removed soil inclusion, using Green's functions for an infinite viscoelastic medium, while half‐space Green's functions are applied in the analysis of the flat half‐space. Such a method was used in the computation of the impedance matrix and of the foundation input motion for square embedded foundations with different embedments. The results are consistent with those obtained in previous studies, especially for the case of shallow foundations.