西安-宝鸡高速公路地震危险性评价

Seismic hazard assessment of Xi'an-Baoji expressway

本文划分了西宝高速公路研究区域地震区带和潜在震源区,采用历史地震资料计算了地震活动性参数,在PGA衰减关系、地震危险性概率计算方法和场地地震动影响分析的基础上,计算了西宝高速公路未来50年超越概率2%、10%和63%的PGA分布,基于Arc GIS绘制了西宝高速公路地震危险性分区图;从设计地震危险性和实际地震危险性2方面总结了公路结构物地震危险性评价方法,开展了漆水河大桥、千河大桥、沣河大桥和渭河大桥等典型结构物的地震危险性评价。研究结果表明:西宝高速公路PGA跨越Ⅶ度和Ⅷ度基本烈度区,评价结果略高于我国第四代地震区划图,这是与渭河断陷盆地地震活跃的现实一致的;漆水河大桥和千河大桥的地震危险性是可控的,沣河大桥和渭河大桥的地震危险性不可控,应采取工程措施进行抗震加固。

Seismic zone and potential hypocentral region division were managed, and seismic parameters were de- termined based on historical earthquake data. On the analysis of attenuation relationship of PGA, seismic hazard probability calculation method and influence of seismic motions, the PGA distribution of exeeedance probabilities of 2%, 10% and 63% along Xi＇an-Baoji expressway within the next 50 years were calculated, and the seismic hazard regionalization map was plotted based on ArcGIS; The assessment method of highway structure object seismic haz- ard were concluded from the aspects of design and practical seismic hazard, the seismic hazard assessment of typi- cal structures of Qishuihe bridge, Qianhe bridge, Fenghe bridge and Weihe bridge were carried out. The results show that Xi＇an-Baoji expressway crosses the land of the basic seismic intensity Ⅶ and Ⅷ, and assessment results are a little bit higher than the fourth generation seismic zoning map, which is consistent with current seismic active state of Weihe fault basin ; Seismic hazard of Qishuihe bridge and Qianhe bridge is controllable, Fenghe bridge and Weihe bridge should be taken engineering measures for seismic reinforcement due to the seismic hazard is uncon- trollable.