The Numerical Simulation Research On Tectonic Stress Field In Key Areas Of Xian Shuihe Fault Belt

Xian Shuihe fault belt is one of the largest fault belts in the west of China, which becomes one of the most active fault zones in the country as well as the whole world, as a result of the significant geomorphic phenomena,such as broken river fault, dislocation terraces, fault, cliff,slope spinal and 1,acting on the surface and the 15mm/a slip rate.This article is on the basis of the Xian Shuihe region related geological data and interpretation of remote sensing and field survey results, selects the Qianning basin, Xia latuo Basin and Kangding new city to establish planar and three-dimensional finite element model focal mechanism solutions, considers Retrieval of L-left order stress and the tectonic stress of the fault zone besides the formation mechanism of Qianning basin, Xia latuo Basin and finally provides quantitative results of the comprehensive analysis and the stability evaluation of the crust in the typical landscape structures-pull-apart basins. Knowledge acquired is as follows:(1) The significant low stress area in the low-stress environment of the fault belt in Qianning basin and Xia Latuo basin has an important controlling role in the formation of the basin. When the local rocks are crushed, the rock bridge area in the secondary fault belt characterized by high stress area often forms the pushing construction.(2) Both sides of fracture unit's stress show a characteristic distribution in four quadrants. The clockwise side is compression zone, and the counterclockwise side is tension zone. The changing of the dip-slip along the different fracture surface sections has a certain control action for the hub of the fault belt. It is usually characterized by two landscapes: deposition and erosion fracture, and positive and negative erosion.(3) The local principal stress vector field is NE-SW compressive stress, and it changes into NE-SW direction in Qianning Basin, which confirms anti-torsion tension effect due to anti-torsion in Yu-order L-left bar fault. The trans-tensional nature of the Middle fracture east-west connected between the Qianning fault and the Yarra River fault is consistent with the actual structural characteristics.(4) In the tectonic stress, high stress area tends to be formed in low-lying valley and contour gradients. With the increasing depth of the stratum, the changes impacted by principal stress are gradually weakened.