Foundation Impedance Matrices by Substructure Deletion

A numerical formulation is presented for a mathematical model of those soil regions bearing flexible embedded structures of arbitrary geometry. The computational difficulties associated with a strict continuum solution for the unbounded foundation domain with an irregular surface geometry, are alleviated by “subtracting” the impedance contribution of the embedded region from the impedance matrix of a foundation with a horizontal surface. The procedure could be utilized for soil-structure analysis in seismic design.