2008年汶川大地震的强地面运动特征与震害关系探讨

项目名称： 2008年汶川大地震的强地面运动特征与震害关系探讨

项目编号： No.41474085

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 胡才博

作者单位： 中国科学院大学

项目金额： 88万元

中文摘要： 2008年汶川大地震发生在人口比较稠密地区，造成了人民生命财产的严重损失。地质考察、宏观烈度分布以及强震记录等表明，汶川大地震的近场震害呈现明显的方向性，山体滑坡、房屋倒塌等分布广泛且差异较大。该地震震级大、地表起伏严重、断层破裂过程复杂、介质分布不均匀，是震害巨大且复杂的重要原因。大量的GPS和InSAR地表变形、地震层析成像、断层破裂过程反演、宽频地震波和强震加速度等资料，为定量研究汶川大地震的强地面运动提供了重要支撑。汶川大地震是研究强地面运动特征和震害之间关系的典型案例。本项目拟利用三维动态有限元动力学模型，从理论上研究断层破裂过程、主震震源区介质不均匀性、地表起伏对汶川大地震强地面运动的影响，深入分析地表零水平应变线及其附近区域的强地面运动和震害的特殊性，探讨强地面运动特征和震害之间的关系。本研究有助于认识汶川大地震震害形成的动力学机制，为防震减灾提供理论参考。

中文关键词： 汶川大地震；近场震害；零水平应变线；强地面运动；有限元动力学模型

英文摘要： 2008 Wenchuan Ms 8.0 earthquake occurred in the region of mass people, which caused terrible loss of life and property. Geological survey, distribution of earthquake intensity, and strong-motion acceleration recordings indicated that seismic damages in the near field located directionally. Landslides and building collapses distributed widely and complexly. The earthquake is with high magnitude, variable topography, complex fault rupture process, and heterogeneity of material, which are the causes of the mass and complex damages. Many data on the GPS/InSAR surface deformation, seismic tomography, inversions of fault rupture process, strong ground acceleration recordings, provided a effective way to study the strong ground motion of Wenchuan earthquake quantitatively. Wenchuan earthquake is a representative example to study the relationship between strong ground motion and seismic damages. We will apply three dimensional dynamic finite element models to study the effects of the complex fault rupture process, variable topography, and heterogeneity of material on the ground motion of the Wenchuan earthquake. We will focus on the specificity of ground motion on or near the lines of surface zero horizontal strain, and discuss the relationship between the simulated strong ground motion and seismic damages. The study will advance the knowledge on the dynamic reasons of the seismic damages.

英文关键词： Wenchuan earthquake;near-field damages;zero horizontal strain line;strong ground motion;dynamic finite element model