Extrusion deformation process of ground surface during the Lushan earthquake in China

作     者：Yuzhu Bai 

作者机构：Key Laboratory of Active Tectonics and VolcanoInstitute of GeologyChina Earthquake Administration 

出 版 物：《Geodesy and Geodynamics》 (大地测量与地球动力学（英文版）)

年 卷 期：2017年第8卷第2期

页      面：84-89页

学科分类：070801[理学-固体地球物理学] 0709[理学-地质学] 07[理学] 0707[理学-海洋科学] 0708[理学-地球物理学] 0705[理学-地理学] 0815[工学-水利工程] 0825[工学-航空宇航科学与技术] 0704[理学-天文学] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：supported by the Basic Research Project of Institute of Geology China Earthquake Administration(IGCEA1503) 

主　　题：Lushan earthquake Extrusion deformation Finite element method 

摘      要：Based on finite element method, the extrusion deformation process of ground surface during the Lushan earthquake （April 20, 2013） is investigated in this work. In order to construct the finite element model of Lushan earthquake structure, the geophysical layer model of Lushan area, the frictional characteristic of slip-weaken along the fault surface, and the Coulomb failure criterion are considered. Through the computation and the comparison with achievement on the Lushan focal dynamics, our researches indicate that： （1） The most extrusion deformation of ground surface occurred in the initial phase of earthquake procession, i.e., between the fourth and sixth seconds after the earthquake occurred. （2） Between the first and sixth seconds after the earthquake, the extrusion deformation concentrates on the surface projection of earthquake fault. （3） Between the first and third seconds after the earthquake, the extrusion deformation of ground surface is very tiny. Meanwhile, the extrusion deformation reaches maximum at the sixth second after earthquake. （4） After 6 s of Lushan earthquake, the extrusion deformation spread out of earthquake structure projection. （5） During the earthquake, the maximum of extrusion deformation on ground surface is larger than the final deformation of the post-earthquake, in other words, the ground extrusion deformation will lastly reach a relatively small value after the Lushan earthquake occurred.