A Feasibility Study of an FEM Simulation Used in Co-Seismic Deformations: A Case Study of a Dip-Slip Fault
A Feasibility Study of an FEM Simulation Used in Co-Seismic Deformations: A Case Study of a Dip-Slip Fault
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DOI：
10.3319/tao.2013.01.16.01(tibxs
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发表时间：
2013-08
影响因子：
0.8
通讯作者：
Xiaoguang Lin;Wenke Sun;Huai Zhang;Xin Zhou;Yaolin Shi
中科院分区：
文献类型：
--
作者：
Xiaoguang Lin;Wenke Sun;Huai Zhang;Xin Zhou;Yaolin Shi
本文采用有限元法对半空间介质中倾滑断层的同震位移进行了数值模拟。在研究了建模、震源和边界处理等技术问题后，计算了考虑地形的同震变形。为了验证数值模拟结果，将模拟的同震位移与位错理论计算的同震位移进行了比较。以2008年汶川8.0级地震的地震参数为震源模型，在有限元模型中计算考虑或不考虑地形模型的同震位移，观察地形对同震变形的影响。结果表明，地形对同震位移的影响不容忽视，水平位移在-11.59 ~ 4.0 cm之间，垂直位移在-3.28 ~ 3.28 cm之间。水平位移和垂直位移的相对效应分别为9.05和2.95%。这种地形效应是足够大的，可以通过现代大地测量，如GPS来检测。因此，我们得出结论，在应用位错理论计算同震变形时应考虑地形。
For this study, we conducted a numerical simulation on co-seismic displacement for a dip-slip fault in a half-space medium based upon a finite element method (FEM). After investigating technical problems of modeling, source and boundary treatment, we calculated co-seismic deformation with consideration to topography. To verify the numerical simulation results, the simulated co-seismic displacement was compared with that calculated using a dislocation theory. As a case study, considering the seismic parameters of the 2008 Wenchuan earthquake (M 8.0) as a source model, we calculate the co-seismic displacements with or without consideration of the terrain model in the finite element model to observe terrain effects on co-seismic deformation. Results show that topography has a non-negligible effect on co-seismic displacement, reaching from -11.59 to 4.0 cm in horizontal displacement, and from -3.28 to 3.28 cm in vertical displacement. The relative effects are 9.05 and 2.95% for horizontal and vertical displacement, respectively. Such a terrain effect is sufficiently large and can be detected by modern geodetic measurements such as GPS. Therefore, we conclude that the topography should be considered in applying dislocation theory to calculate co-seismic deformations.