Simulation of Multidimensional, Anisotropic Ground Motions

Abstract

A recently developed technique for the digital simulation of spatially incoherent seismic ground motions is extended to include two or three spatial coordinates. This extended approach allows for four situations: (1) Simulation in the far field; (2) simulation in the near field of a small source; (3) simulation in the near field of an extended source; and (4) simulation in the near field of a limited source. In each situation, both direction‐dependent (isotropic) and direction‐dependent (anisotropic) coherency structures are accounted for. The developments proposed may facilitate the seismic analysis of structures involving foundation coupling in two or three dimensions accounting for ground motion spatial incoherence, response nonstationarity, and system nonlinearities. They can also be useful in evaluating the response of structures to other spatially variable random fields such as those of wave forces and turbulent winds.