乌鲁木齐市活断层强地面运动预测研究
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摘要
介绍了基于乌鲁木齐活断层发震构造模型的强地面运动的预测结果。该项工作是在乌鲁木齐城区开展的活断层探测与地震危险性评价的基础上,设定了两个发震构造,分别为北天山山前逆冲推覆构造和博格达弧西翼逆冲推覆构造,前者可能最大地震震级为7.5级,后者为7.0级,据此建立了分析计算模型。根据地脉动观测分析结果,结合浅层地震勘探、地质图、地形图和钻孔资料,建立了地下三维速度模型,采用统计学的格林函数法、三维有限差分法和混合计算方法,对目标区的地震动进行了预测研究。预测结果表明,断层的结构、破裂方式和三维速度模型对地震动的分布具有显著的影响。沿断层前缘、盆地边缘、覆盖层较厚的地区,以及断层破裂的前方地震动比较显著。
The paper introduced the strong ground motion prediction results based on seismo-tectonic model of Urumqi active fault.During detecting active fault and assessing earthquake risk in Urumqi,two seismo-tectonics models were set.They were thrust nappe structure in front of northern Tienshan Mountain and in west side of Bogeda arcuate structure respectively.The possible max-magnitude of the former was about 7.5 and that of the latter was about 7.0,so the analytical or computational model was established.According to analysis result of microtremor observation,combined with shallow seismic exploration,geological map,topographic map and borehole data,the underground three dimensional speed model was founded.The statistical Green function,3D finite-difference and hybrid computation methods were used to research ground motion in target area.The prediction result showed the structure of fault,mode of fault failure and three dimensional speed model influenced the distribution of ground motion obviously.The ground motion was evident along fault front,basin margin,in the area with thicker covering layer and front of fault failure.
The paper introduced the strong ground motion prediction results based on seismo-tectonic model of Urumqi active fault.During detecting active fault and assessing earthquake risk in Urumqi,two seismo-tectonics models were set.They were thrust nappe structure in front of northern Tienshan Mountain and in west side of Bogeda arcuate structure respectively.The possible max-magnitude of the former was about 7.5 and that of the latter was about 7.0,so the analytical or computational model was established.According to analysis result of microtremor observation,combined with shallow seismic exploration,geological map,topographic map and borehole data,the underground three dimensional speed model was founded.The statistical Green function,3D finite-difference and hybrid computation methods were used to research ground motion in target area.The prediction result showed the structure of fault,mode of fault failure and three dimensional speed model influenced the distribution of ground motion obviously.The ground motion was evident along fault front,basin margin,in the area with thicker covering layer and front of fault failure.
引文
[1]沈军,宋和平.乌鲁木齐城市活断层探测与地震危险性评价主要成果简介[J].地震地质,2008,30(1):274-288.
[2]沈军,宋和平,李军.乌鲁木齐城市活断层发震构造模型初探[J].内陆地震,2007,21(3):193-204.
[3]Boore D M.Stochastic simulation of high-frequency ground motion based on seismological models of th radiated spectra[J].Bul-letin Seismological Society of America,1983,73:1 865-1 894.
[4]Kamae K,Irikura K.Prediction of site specific strong ground motion using semi-empirical methods[C]//10th World Conferenceon Earthquake Engineering,Madrid,1992,801-806.
[5]Irikura K.Prediction of strong acceleration motion using empirical Green'sfunction[C]//Proc of7th Japan Earthquake EngineerSymposium.1986,151-156.
①赵伯明.乌鲁木齐主要活断层地震危害性评价报告,2007.
[2]沈军,宋和平,李军.乌鲁木齐城市活断层发震构造模型初探[J].内陆地震,2007,21(3):193-204.
[3]Boore D M.Stochastic simulation of high-frequency ground motion based on seismological models of th radiated spectra[J].Bul-letin Seismological Society of America,1983,73:1 865-1 894.
[4]Kamae K,Irikura K.Prediction of site specific strong ground motion using semi-empirical methods[C]//10th World Conferenceon Earthquake Engineering,Madrid,1992,801-806.
[5]Irikura K.Prediction of strong acceleration motion using empirical Green'sfunction[C]//Proc of7th Japan Earthquake EngineerSymposium.1986,151-156.
①赵伯明.乌鲁木齐主要活断层地震危害性评价报告,2007.
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