【摘要】 为了评估汶川地区公路桥梁系统地震损失风险,基于汶川地震桥梁震害调查,建立了桥梁地震易损性统计模型.采用修正后的汶川地震衰减模型,对桥址处地震动参数PGA进行了估算.假设易损性函数为双参数对数正态分布函数,采用两种不同的统计方法并结合震害调查,运用极大似然法对参数进行估计,得到轻微破坏、中等破坏、严重破坏、完全损毁4种损伤状态对应的桥梁地震易损性曲线.依据桥梁类型和桥梁线形对全体桥梁样本进行分类,针对分类后的桥梁样本子集建立各自独立的地震易损性曲线.对统计结果进行拟合优度检验,结果显示显著性水平在10%以下,计算得到的易损性函数不能被拒绝.更多还原

【Abstract】 In order to evaluate the seismic loss risk of highway bridge systems in Wenchuan area,Sichuan,China,statistical seismic vulnerability models of bridges were established based on the collected bridge damage data from the Wenchuan earthquake.A modified Wenchuan earthquake attenuation model was developed for estimating the ground motion parameter,i.e.,peak ground acceleration(PGA),at various bridge sites.Two-parameter lognormal distribution functions were assumed to be suitable for developing fragility functions.Combined with the surveyed earthquake damage data,two different statistical models were then used to estimate the parameters based on the maximum likelihood method,and the bridge seismic fragility curves corresponding to four damage states(including minor,moderate,major,and collapse) were generated.According to the type and configuration of bridges,the surveyed bridge samples were categorized and distinct fragility curves of the sub-sample bridges were established.Goodness of fit test of the statistical results was carried out.The results show that the fragility functions cannot be rejected under the 10% significance level.更多还原