我国地震灾害损失评估业务中的易损性模型对比研究OA

The seismic fragility model of engineering structures is a critical component in probabilistic seis-mic risk assessment.Currently,seismic fragility models used for earthquake disaster risk assessment in China often exhibit oversimplifications in engineering structure classification and key parameter selection,increasingly becoming a limitation in advancing refined seismic risk assessment practices.To explore the influence of the re-finement degree of fragility models on seismic disaster loss estimation,this paper takes 686 existing reinforced concrete(RC)frame structures with diverse characteristic parameters in Shaanxi Province as research objects,and calculates their seismic economic losses by adopting fragility models with different refinement levels under the same seismic hazard conditions.The refined fragility curve family and average fragility curves of the 686 ex-isting RC frame structures are established based on the support vector regression method.Three groups of seis-mic damage matrices for RC frame structures commonly used in practical seismic disaster loss assessment and the GEM seismic fragility curves for Chinese RC frame structures are collected for comparative analysis with the refined fragility model proposed in this paper.The models involved in the comparison are as follows:① A re-fined fragility model based on support vector regression that takes eight characteristic parameters of buildings into account;② The seismic fragility model for domestic RC frame structures in the Global Earthquake Model(GEM);③ Three fragility models based on seismic damage matrices widely used in routine engineering practic-es in China.The results show that when estimating the total seismic disaster losses of a large number of buildings in the study area,the calculation results of the refined fragility model are close to those of its corresponding aver-age fragility model.The maximum difference rate λ between the estimations of the refined fragility curve family and the average fragility curves in this study is merely 3.02%.The fragility models based on seismic damage ma-trices adopted in domestic engineering practices suffer from unreasonable damage grade intervals and excessive data dispersion,and their assessment results differ remarkably from those of the average refined fragility model.The proposed refined fragility model can generate a set of tailored fragility curves according to the characteristic parameters of each individual structure.It realizes the refinement of fragility models in seismic disaster loss as-sessment,resolves the problem of coarse granularity in disaster-bearing body classification and key parameter se-lection of conventional fragility models,and further improves the accuracy and reliability of assessment results.