NUMERICAL SIMULATION OF INFLUENCES OF MEDIUM HETEROGENEITY AND DIP OF FAULT ON COSEISMIC DISPLACEMENT
Li Feng 1,2) ; and Huang Jinshui 1,2)
1)School of Earth and Space Sciences,University of Science and Technology of China, Hefei 2300262)Mengcheng National Geophysical Observatory, Hefei 230026
Abstract：In order to quantify the effect of medium heterogeneities and the dip of the fault on the coseismic displacement, threedimensional finite element numerical method was applied. The selected slip distribution models including finite rectangular strike, normal and reverse fault.The numerical simulation has given following results.1) For the vertical strike earthquake in the homogeneous and vertically layed mediums, the coseismic displacement slightly depends on the Poisson’s ratio, the relation between horizontally displacements and Poisson’s ratio is negative, and it is positive for the vertical displacements. The relation between horizontally displacements and shear modulus is positive, and it is negtive for the vertical displacements; 2) In horizontally heterogeneous medium, the shear modulus plays a significant role on the surface displacements, the relation between shear modulus and displacement field is negative, in the case of the medium parameters on the right block of fault remain unchanged, the increase extent of maximum vertical displacements on the left block of fault reaches 55.6% and the shear modulus of the left block of fault halved.3)In the neighborhood of fault,the dip angle of fault dominate the coseismic displacements, as for the reverse fault earthquake with high dip (60°-90°), opposite direction region appears in the horizontal displacements on the hanging wall, the range of opposite direction region increase with dip-angle;and the increase extent of coseismic displacements on the foot wall is obvious.
Li Feng,and Huang Jinshui. NUMERICAL SIMULATION OF INFLUENCES OF MEDIUM HETEROGENEITY AND DIP OF FAULT ON COSEISMIC DISPLACEMENT[J]. jgg, 2011, 31(5): 52-60.
