Study on earthquake dynamic response of non-causative faults site

Twelve ideal fault site models are established by considering factors, such as fault dip, depth of fault trace, thickness of fault fracture zone. The viscoelasticity artificial boundary is used in models to prevent the reflection of travel-out wave. After inputting the artificial seismic wave, the faults’ effect on sites earthquake response is analyzed by 2-dimensional dynamic finite-element method and the displacement in time domain of sites is given. It is found that faults have influence on the dynamic response of site which can’t ignored, and the closer to fault, the more remarkable the amplification effect of earthquake motion is. To vertical fault, the amplification effect of site is symmetrical distribution. To inclined fault, the amplification effect of hanging plate site is more remarkable than lying plate site’s. Increasing the depth of fault will cause the greater changes in earthquake motion of site, but the increasing in thickness of fault will cause very slight changes in earthquake motion of site. Furthermore, the research results indicate that, at the boundary of fault fracture zone, the wave mode changes greatly, but at middle place of fault fracture zone, the wave mode change is slight.