汶川地震中九襄断裂对汉源烈度异常的影响  

Effects of Jiuxiang Fracture on Abnormal Intensity in Hanyuan during Wenchuan Earthquake

作　　者：李平[1] 薄景山[1] 袁一凡[1] 肖瑞杰[1] 刘红帅[2] 

机构地区：[1]防灾科技学院综合减灾研究所,河北三河065201 [2]中国地震局地壳运动监测工程研究中心,北京100036

出　　处：《西南交通大学学报》2015年第6期1055-1060,1073,共7页Journal of Southwest Jiaotong University

基　　金：中国地震局地震科技星火计划资助项目(XH15067Y);国家自然科学基金资助项目(50978237);中央高校基本科研业务费专项资金资助项目(ZY20140205)

摘　　要：为分析汶川地震中九襄断裂对汉源县高烈度异常的影响,基于对汉源县城震害的科学考察、场地勘察以及地震地质与地形图,建立了典型的二维地震反应分析模型,采用有限差分法和透射边界理论,分析了九襄断裂对汉源县城震害的影响.结果表明：九襄隐伏断裂对汉源烈度异常有一定影响,对频段在4～8 Hz之间的地震动放大效应显著,使地表地震动峰值加速度约增大9%;该频段与汉源县城部分建筑物的自振频率吻合,放大的地表地震动和共振效应加重了汉源县城的震害,是汉源高烈度异常的主要原因之一.因此,场地中的非发震隐伏断裂对地表地震动有一定放大效应,工程选址和抗震设计时应考虑其影响。In order to explore the causes for abnormal intensity occurring in Hanyuan Town during the Wenchuan earthquake,a typical two-dimensional model for seismic response analyses was established based on the scientific investigation and site reconnaissance of earthquake damages in Hanyuan Town and the seismogeologic and topographic maps,and the effects of Jiuxiang fracture on abnormal seismic damage in Hanyuan Town were analyzed by the finite difference method and the transmitting boundary theory. The research results show that there is a certain effect of Jiuxiang fracture on abnormal intensity in Hanyuan Town,and the ground motion may be amplified significantly in the band of 4 to 8 Hz,the peak ground motion acceleration being increased about 9%. This frequency band is the same as the vibration frequency of buildings in Hanyuan Town. Damages can be aggravated by the increased surface ground motion and resonance effect,this is one of the main reasons of high abnormal intensity in Hanyuan Town. So a non-causative fault has certain amplification effect on surface ground motion,the effect should be considered in project location and anti-seismic designs.

关 键 词：汶川地震 断裂 有限差分法 地震动 抗震设计 

分 类 号：P315[天文地球—地震学]