The coherence function model of ground motion in engineering sites based on physical mechanism

Abstract

Based on the random physical model of seismic ground motion field on local engineering site, this paper suggests a theoretical coherence function model of ground motion in engineering sites based on physical mechanism; probability density evolution method (PDEM) is used to solve this theoretical model. The comparison between the theoretical model and the Harichandran-Vanmarcke model as well as Hao model has proved the rationality of the suggested model. Then the model is used to study the characteristics of the coherence function in four kinds of seismic engineering sites and the non-uniform sites in lateral direction. When compared with the traditional empirical or semi empirical models, the model suggested in this paper provides a new perspective to understand the coherence in earthquake field, which means to determine the earthquake field coherence based on different kinds of physical factors and the physical mechanism of seismic wave propagation. This can be a new method to analyze and determine the earthquake field coherence.