九寨沟MS7.0地震对巴颜喀拉块体东北缘活动断裂影响的有限元模拟

Impact of the Jiuzhaigou MS7.0 earthquake on the activity faults around the northeastern Bayan Har block: Insights from finite element simulation

摘要:

在详细调研地震地质资料的基础上，构建了巴颜喀拉地块东北缘三维有限元模型。以九寨沟M_S7.0地震同震位错为荷载，模拟计算了九寨沟地震的发生对巴颜喀拉块体东北缘主要活动断裂加卸载效应的影响。模拟结果显示，九寨沟地震的发生对龙日坝断裂、虎牙断裂、青川-平武断裂西段、迭部-白龙江断裂西段和东段、临潭-宕昌断裂东段，以及处于甘青川交界危险区内的东昆仑断裂东段、塔藏断裂西段，处于六盘山南-西秦岭东危险区的西秦岭北缘断裂东段表现为库仑应力加载；对岷江断裂、塔藏断裂东段库仑应力卸载效应显著。

Abstract:

Based on the investigation of the geology literature, we built a 3-D finite element model of the northeastern Bayan Har block. With the model by the coseismic dislocation, the loading or unloading effects of the Jiuzhaigou earthquake on the activity faults around the northeastern Bayan Har block is simulated in this paper. The results show that impacted by the Jiuzhaigou earthquake, the Coulomb stress increased significantly on the west segment of Tazang Fault and Huya Fault and decreased on the Minjiang fault and the east segment of Tazang Fault. There are also some degrees of Coulomb stress loading on the east segment of Dongkunlun Fault, the Longriba fault, the west segment of Pingwu-Qingchuan fault, the west and east segment of Diebu-Bailongjiang fault, the east segment of Lintan-Tanchang fault and the east segment of Xiqinling Fault.