Dynamic modelling of axisymmetric foundations

Abstract

Abstract A boundary impedance matrix to characterize a homogeneous half‐space with a cylindrical cavity is formulated by the global Ritz method. This method, which is basically the same as the indirect boundary element method, uses a very limited number of distributed sources to generate Ritz vector sets representing the far‐field impedances. The resulting impedance matrix is fully‐coupled, complex‐valued, frequency‐dependent and can be combined with any compatible finite element near field for carrying out soil–structure interaction analyses. The numerical results obtained by this method for surface supported and embedded foundations are very close to corresponding published results obtained by different procedures. Combining the boundary impedance matrix with a finite element near field provides an hybrid model which is effective and efficient in carrying out dynamic soil–structure interaction analyses.