中国地震科学实验场断层系统的三维计算网格模型  

3D Mesh for the Fault System in China Seismic Experimental Site

作　　者：张熔鑫 邢会林 舒涛 刘骏标 郭志伟 王建超[1,2,3] 谭玉阳 ZHANG Rong-xin;XING Hui-lin;SHU Tao;LIU Jun-biao;GUO Zhi-wei;WANG Jian-chao;TAN Yu-yang(Frontiers Science Center for Deep Ocean Multispheres and Earth System,Key Lab of Submarine Geosciences and Prospecting Techniques,MOE and College of Marine Geosciences,Ocean University of China,Qingdao 266100,China;Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China;International Center for Submarine Geosciences and Geoengineering Computing(iGeoComp),Ocean University of China,Qingdao 266100,China)

机构地区：[1]深海圈层与地球系统前沿科学中心,海底科学与探测技术教育部重点实验室,中国海洋大学海洋地球科学学院,山东青岛266100 [2]青岛海洋科学与技术试点国家实验室,山东青岛2266237 [3]中国海洋大学海底科学与工程计算国际中心,山东青岛266100

出　　处：《地震》2023年第3期18-33,共16页Earthquake

基　　金：地震数值预测联合实验室开放基金项目(2020NEF02)。

摘　　要：川滇地区受印度板块与欧亚板块碰撞运动影响地震频发,是开展地震研究的理想实验场。为实现基于几何模型的三维断层系统有限元模型快速构建,本文以川滇地区断层系统的主要断层几何模型为基础进行了以下研究。①改进了推进波前法,使其能够基于几何模型生成三维曲面的三角形网格,并自动识别需要局部加密的区域以及进行网格加密。②提出了交叉断层的交叉线识别算法,根据非参数曲面间的空间几何关系识别不同面(包括断层面与研究区域边界)之间的相交线。③完善了三维断层系统有限元计算网格模型快速构建方法:对原始断层几何模型进行延长、连接等操作,使其能在几何上代表断层真实形状;将研究区域外边界与内部断层面整合,并识别它们之间的交叉线;以交叉线为约束,使用改进的推进波前法对断层面进行网格重划分,修复网格拓扑关系和提高网格质量;最后,以断层面新生成的三角形面网格为约束,自动生成含断层的四面体计算网格模型。(4)将上述方法应用于中国地震科学实验场,构建了川滇地区断层系统的三维计算网格模型,为利用有限元数值模拟研究该区域地震动力学过程奠定了计算网格模型基础。The Sichuan-Yunnan region is subjected to frequent earthquakes due to the collision of the Indian and Eurasian plates,rendering it an ideal experimental site for seismic research.This paper presents a rapid method for constructing a finite element mesh model with complex faults based on a geometric mesh model of the region,using the example of the geometry model of major faults in fault system of Sichuan-Yunnan region.The following research has been conducted:①The Advancing Front Technique(AFT)has been improved to generate a three-dimensional triangle mesh based on the geometric model,and automatically identify areas that require local refinement and conduct mesh refinement.②An algorithm for identifying the intersection lines of intersecting faults has been proposed,and it can recognize the intersection lines between different surfaces(including fault surfaces and study area's boundaries)based on the spatial geometric relationship between non-parametric surfaces.③The rapid method for constructing a finite element mesh model with complex faults based on a geometric mesh model of the region has been improved.First,the original fault model is manipulated using expansion and connection operations to enable it to represent the true shape of the fault geometrically.Subsequently,the boundary of the study area and the fault mesh are combined.The intersection lines between different fault planes or between fault planes and the study area's boundary are then identified.Then,using the improved advancing front technique,the fault surface is remesh with the intersection lines as constraints to repair the mesh topology and improve the mesh quality.Finally,a tetrahedral calculation mesh model containing faults is automatically generated using the newly generated triangular mesh of the fault surface as constraints.④The above method has been applied to the China seismic experimental site to construct a three-dimensional calculation mesh model containing the main fault system which lays the foundation for using finite elem

关 键 词：川滇地区 断层系统 有限元网格生成 推进波前法 

分 类 号：P315.7[天文地球—地震学]