A random physical model of seismic ground motion field on local engineering site

This paper presents a random physical model of seismic ground motion field on a specific local engineering site. With this model, artificial ground motions which are consistent with realistic records at SMART-1 array on spatial correlation are synthesized. A two-scale modeling method of seismic random field is proposed. In large scale, the seismic ground motion field on bedrock surface is simplified to a two-dimensional spherical wave field based on the seismic point source and homogeneous isotropic media model. In small scale, the seismic ground motion field on the engineering site has a plane waveform. By introducing the physical models of seismic source, path and local site and considering the randomness of the basic physical parameters, the random model of seismic ground motion field is completed in a random functional form. This model is applied to simulation of the acceleration records at SMART-1 array by using the superposition method of wave group.