汶川地震巨型滑坡与断层位错InSAR同震形变场耦合效应研究

项目名称： 汶川地震巨型滑坡与断层位错InSAR同震形变场耦合效应研究

项目编号： No.41472255

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 地质学

项目作者： 陈强

作者单位： 西南交通大学

项目金额： 82万元

中文摘要： 汶川地震触发龙门山大量同震巨型滑坡，发震断层的位错运动是诱发同震巨型滑坡的直接初始驱动因素，探索和阐明地震滑坡与断层位错同震形变场的耦合关系，可为龙门山强震作用下的斜坡失稳分析和灾害预测提供重要的构造形变科学依据。本项目提出基于多孔径InSAR与震时高频GPS联合观测的方法，采用地壳分层弹性位错模型反演近断层连续深度空间的精细同震形变场，计算强地震动在不同深度和方向引发特征各异的三维同震形变梯度，分析地面滑坡运动特征和空间分布格局受断层位错滑移的控制响应关系。采用映秀-北川发震断裂带两侧滑坡区的地形地貌与地质岩性参数，建立断层位错形变作为触发同震巨型滑坡主导敏感因子的定量评估模型，获得滑坡分布密度与同震形变幅值的数值耦合关系，揭示滑坡初始滑动与断层位错滑移的方向耦合效应，促进对龙门山区强震诱发滑坡致灾机理的科学认识与灾害预测能力。

中文关键词： InSAR；巨型滑坡；断层位错；耦合效应；同震形变场

英文摘要： The Wenchuan earthquake triggered massive coseismic giant landslides in the Longmenshan mountainous area. The fault dislocation and intense ground motion are the direct causal factor of large scale coseismic landslides. The study on the coupling mechanism between fault dislocation and coseismic landslides is helpful to further understand the geohazard process and provide the tectonic deformation evidence for slope failure triggered by the earthquake. The combination observation methods based on multiple aperture radar interferometry and near-field high-rate GPS are proposed to investigate the coseismic displacement field from the earth crust layering dislocation model. The deformation gradient field can be computed at different directions from the derived displacement field. The sensitivity relationships between landslide motion feature, spatial distribution and coseismic deformation are to be analyzed in the project. The topographic and geological data of the representative coseismic landslides near the Yingxiu-Beichuan fault are to be used to establish the quantitative evaluation model with coseismic dislocation deformation as one of sensitivity factors. The numerical and directional coupling relationships respectively between landslide distribution density and coseismic displacement magnitude, slope failure motion direction and coseismic deformation vectors are to be investigated in the project. This proposal aims to reveal the spatial coupling effect between coseismic giant landslides and fault dislocation deformation and promote the capability of analyzing and evaluating the risk of slope failure triggered by the high magnitude earthquake over the Longmenshan area.

英文关键词： InSAR;Giant landslides;Fault dislocation;Coupling effect;Coseismic deformation field