Numerical Simulation of Tectonic Stress Field in Longmenshan Tectonic Belts after Earthquake

Two-dimensional finite element model of Longmenshan area was built on the basis of depth study on geological structure conditions and of rock mechanical properties in Longmenshan area, tectonic stress field and variation process of Longmenshan fault belt were imversed after the earthquake. The results show that: (1)After the earthquake, the maximum principal stress appears in fault endpoint, partial inflection point, intersection of Longmenshan fault and Xianshuihe fault and intersection of Minjiang fault, Animaqing-lueyang fault and Longmenshan Fault. The maximum principal stress in area is overall NEE to SEE.(2)After earthquake, shear stress distribution is more uniform, and compared after earthquake to before earthquake, shearing stress of Longmenshan central fault and Qianshan fault reduces obviously, but shear stress of Houshan fault increases.