乌东德水电站设定地震及场地相关设计反应谱研究

Study on scenario earthquake and site-specific design response spectrum of Wudongde Hydropower Station

乌东德水电站坝址地震地质条件复杂、基本烈度高、防震抗震问题突出。为合理评价乌东德大坝等抗震设防类别为甲类的重要建筑物抗震安全性能,采用了概率法和确定性方法相结合的设定地震方法,结合工程场地地震安全性评价给定的输入参数、衰减关系和设计地震动加速度值,依据发生概率最大的原则和潜在震源中主要发震构造,确定了设定地震的震级和震中距,同时选用美国NGA中的AS08反应谱衰减关系,得到了与场地地震地质条件相关的加速度反应谱。结果表明:场地相关设计反应谱能真实反映坝址工程地震地质条件,其作为大坝抗震分析的依据是合适的。

The dam site of Wudongde Hydropower Station has complex seismic geological conditions,high basic earthquake intensity and outstanding problems of earthquake resistance.In order to reasonably evaluate the seismic safety performance of Wudongde dam and other important buildings whose seismic fortification category is class A,by adopting a scenario earthquake method combining probability method and certainty method,combining with the input parameters,attenuation relationship and design seismic dynamic acceleration given in the seismic safety evaluation of the project site,and according to the principle of maximum probability of occurrence and the main seismogenic structure in the potential source,the magnitude and epicentral distance of the scenario earthquake are deter⁃mined.At the same time,the attenuation relation of AS08 response spectrum in NGA of the United States is selected,and the acceleration response spectrum related to the site seismic geological conditions is obtained.The re⁃search shows that the site related design response spectrum can truly reflect the engineering seismic geological con⁃ditions of the dam site,and it is suitable as the basis for the seismic analysis of the dam.