论工程场地地震安全性评价中历史地震影响烈度的分析方法──以南澳跨海大桥为例

View of the Analyzing Methods on the Response intensity of Historical Earthquakes in Seismic Safety Assessments at Engineering Sites -Results of the Trials on the Spanning Strait Bridge at Nan'ao

合理地确定场地的历史地震影响烈度，是工程场地地震安全性评价工作中的重要一环。本文以广东南澳跨海大桥场址为例，论述了历史地震影响烈度分析的要点。首先对南澳附近１９１８年７．３级地震的震中位置及对桥址的影响烈度进行了确认；其次对选择合适的区域地震烈度衰减关系进行了分析比较，并建立了合理的桥址影响烈度目录；最后应用极值统计分析方法，得到不同平均重现期所对应的烈度值，为大桥的抗震设计提供了设防依据。

It is an important link to determine the response intensity of historical earthquakes at a site reasonably in seismic safety assessments of engineering sites. In this paper, as an example of Nan'ao spanning strait bridge, main points of analysing the response intensity of historical earthquakes have been expounded. First, the epicenter of earthquake with M=7.3 near Nan'ao and the response intensity of the bridge site are determined;Second, the elected attenuations of intensity are analysed and compared in the region,a catalog of the response intensity at the bridge site has been established reasonably.Finally, the intensities corresponding the different recurrent periods are calculated by usiny the extremal statistics analysing method, which provide defense foundation for a seimic design of the bridge.