城市建筑群概率地震灾害风险评估研究

科学合理地考虑地震风险评估中各环节的不确定性是地震风险评估结果可靠的基础。该文利用某城市现有工程场地地震安全性评价数据，综合考虑城市地震危险性评估中的不确定性，以结构基本类作为城市建筑群模型，并考虑地震动不确定性对建筑群地震易损性的影响，建立了同时考虑地震危险性和地震易损性不确定性的地震风险评估模型，最终给出城市结构基本类不同极限破坏状态的年平均超越概率和50年内地震风险概率。基于结构不同极限破坏状态对应的损失比，获得每一种结构基本类的地震经济损失风险曲线。在此基础上，提出了采用地震风险一致概率为控制点，得到城市建筑群总的地震经济损失风险曲线组合的方法，该方法可为评估城市建筑群概率地震风险提供参考。

STUDY ON THE PROBABILISTIC SEISMIC DISASTER RISK ASSESSMENT OF URBAN BUILDING COMPLEX

It is the basis for a reliable result to consider the uncertainties in all aspects of seismic risk assessment scientifically and reasonably.This paper established a seismic risk assessment model in which the uncertainties of seismic hazard and structural vulnerability are taken into account comprehensively.In this model,the uncertainty of seismic hazard assessment(SHA)was discussed by using the data of earthquake safety evaluation for engineering sites in a city.Meanwhile,the impact of ground motion uncertainty on structural vulnerability of urban building complexes(UBCs)were analyzed on the basis of the basic structure classes(BSCs)of UBCs.Based on the above study,the mean-annual-exceeding probability and the earthquake risk probability within 50 years at different damage state thresholds of the urban BSCs were obtained.Moreover,the seismic economic loss risk curve for each BSC was drawn according to the loss ratios corresponding to different damage state thresholds.Finally,the general seismic economic loss risk curve for UBCs in a city was combined by using control points with equal probability in each curve of individual buildings,which provided a reference for assessing the seismic risk of UBCs.