Abstract:

Dynamic response characteristics of the structures constructed on a deep overburden layer are affected obviously by the seismic motion characteristics of soil layer, because the characteristics of seismic motion transmitted from the bedrock under this deep layer are varied greatly by the deep overburden layer. This paper develops the analysis models of ground seismic response considering the horizontal and vertical structural characteristics of the deep overburden layer, and studies the influences of these structural characteristics on the seismic motion of soil layer using a finite element method based on effective stress analysis. The results show that the seismic motion characteristics of deep overburden layer are affected greatly by topographic condition of bedrock, thickness of soil layer, variations of structural characteristics in horizontal direction, existence of soft layer, and new structures constructed on ground. The structural characteristics of soil layer has a relatively complicated influence on the seismic motions of soil layer, it not just significantly affect the amplitude of seismic motion input from bedrock, but also apparently vary the frequency spectrum characteristics of the seismic motion.