Abstract: How to determine the most dominant potential seismic source(PSS) to seismic hazard at site is discussed, taking Qinghe Town(E116.33?,N40.03?) and the dam of Miyuan reservoir, Beijing as examples. The most dominant PSS is same at different periods for Qinghe Town site and it is Beijing PSS located by the site. When the site is the dam of Miyuan reservoir and the annual exceedence probability is less than 1.00E-2, the most dominant PSS is Huairou PSS located by the site for period (0.1s), but the most dominant PSS is Xiadian PSS for period (1.0s). The change also shows that the closer PSS has more important effect at short period (for exapmle,T=0.1s) and the distant PSS is opposite. To distinguish the most dominant PSS at different periods is significant in determining scenario earthquake or designed earthquake to calculate duration time of ground motion.

Key words: Potential earthquake zone, Seismic risk analysis, Seismic attenuation

摘要： 分别以北京市清河镇和密云水库大坝邻近地区作为场地,讨论了贡献量最大潜在震源区的确定问题。对于北京市清河镇场地,不同周期下对场地贡献量最大的潜在震源区都是北京潜在震源区;但对于密云水库大坝邻近地区,在年超越概率小于1.00E-2 条件下,短周期(T=0.1s) 时对场地贡献量最大的潜在震源区是怀柔潜在震源区,而长周期(T=1.0s) 时对场地贡献量最大的潜在震源区是夏垫潜在震源区。这种变化说明近源在短周期时所起作用较为明显,而远源对长周期部分的贡献量增大。区分不同周期下贡献量最大的潜在震源区,对于确定期望地震或设定地震以及计算场地地震动持续时间等参数是重要的。

关键词: 潜在震源区, 地震危险性分析, 地震衰减