检验概率地震区划图的两条技术路线

Two technical paths for testing of PSHA map

文章提出检验概率地震区划图的原则和两条技术路线。以区划图颁布实施后发生的破坏性地震为客观的检验标准,技术路线1统计实际地震造成的烈度超过区划图相应值的面积总和的占比,技术路线2评估按区划图设防建造房屋在实际地震中减轻经济损失和人员伤亡的效益。以我国1990版区划图为例,路线1的检验结果显示,设防烈度被超过的面积总和占大陆地区总面积的2.9%,相当于50年中有5.6%的超越,低于编图中设定的超越概率10%。以四川省最普遍的砖混和钢混结构房屋为例,与不设防相比,按1990版区划图设防建造的房屋在汶川地震中经济损失减少723亿元,体现经济效益621亿元,死亡减少10285人、重伤减少40716人,减灾效益显著。

The principle and two technical paths for testing of PSHA map are presented in this article.Taking the data of destructive earthquakes occurred after the map issued as the objective criterion for the test,the path 1 counts up the all underestimation areas where actually happened intensities are higher than intensities on the map at the same positions,and calculates the ratio of the total underestimation area to the entire area covered by the map,the path 2 evaluate the benefit of the buildings fortified from the map as difference between the reduction of the total economic losses during the quakes and cost of the fortification,and the reduction of total casualty.By case study of the 1990 map of China with earthquake data from 1990 to 2015,the result of the path 1 shows that the percentage of the total underestimation area to the entire area of China mainland is 2.9%,which corresponds to an exceeding probability 5.6%in 50 years,lower than the 10%given in the compiling of the map.By study of the most common buildings with brick-concrete and frame structures in Sichuan province with the data of Wenchuan earthquake,result of the path 2 shows that the reduction of economic loss reaches 72.3 billion RMB,the benefit is 62.1 billion RMB by minus the fortification cost 10.2 billion,and death and serious injury reduced 10285 and 40716 persons respectively.