摘要
首先根据历史地震目录 ,计算了我国 34个省会城市所受到的历史地震影响 .这些城市的地震影响烈度分布特征表明 ,约 5 3%的省会城市没有遭受过Ⅵ度以上的历史地震影响 ,遭受过Ⅶ～Ⅸ度影响的城市有 4 4% ;大部分城市Ⅵ度地震影响的发生频次均高于Ⅵ度以上地震影响 ;不同城市最大发生频次的地震影响烈度也不同 .为此 ,在确定城市地震防御烈度时 ,需综合考虑最大影响烈度和最频影响烈度 .本文还考虑到历史地震记录的不完备性 ,以福建省 6 9个县级以上城市为研究对象 ,采用模拟地震目录的方法来研究城市地震影响的特征 .结果表明 ,不同超越概率水平下城市地震影响烈度在不同城市之间表现出较大变化 ,以 5 0年超越概率 2 %作为城市特征地震影响烈度 ,可以作为城市地震防御烈度确定的依据 。
Firstly, the impact of historical earthquakes on 34 China province level capital cities are evaluated by using historical earthquake catalog. The result of distribution of affected intensity shows, about 53% of cities have even not been affected by earthquake intensity Ⅵ, and 44% of cities have been hit by earthquake intensity Ⅶ to Ⅸ. For most of the cities, occurrence frequency of affected intensity Ⅵ is usually higher than that of affected intensity larger than Ⅵ, and the value of affected intensity with maximal occurrence frequency may be very different among cities. So both the maximal affected intensity and the affected intensity with maximal occurrence frequency should be taken into account when the prevention seismic intensity needs to be determined. Secondly, considering the incompleteness of records of historical earthquake, a method of earthquake catalog computer simulation is introduced to study the features of affected intensity of big cities. 69 county level cities of Fujian Province are selected to be statistical objects. The statistic result shows, for different probability of exceedance the seismic intensity of earthquake changes greatly among cities, the seismic intensity of 2% probability of exceedance in 50 years can be regarded as the characteristic affected intensity of earthquake in a city, and can be the basis of determining the city special earthquake prevention level and a proper indicator of future earthquake′s impact on city.
出处
《地震学报》
CSCD
北大核心
2004年第2期203-210,共8页
Acta Seismologica Sinica
基金
科技部社会公益性研究项目"城市群防震减灾综合研究"资助
关键词
城市
地震影响烈度
特征地震
超越概率
city
affected intensity
characteristics earthquake
probability of exceedance
