基于KDE的高烈度区典型简支梁桥地震易损性分析  

Seismic fragility of typical simply supported bridge using kernel density estimation in high seismicity region

作　　者：胡明亮 HU Mingliang(Sichuan Road and Waterway Construction Engineering Co.,Ltd.,Chengdu 610045,China)

机构地区：[1]四川路航建设工程有限责任公司,四川成都610045

出　　处：《铁道科学与工程学报》2022年第1期198-207,共10页Journal of Railway Science and Engineering

基　　金：四川省科技计划资助项目(2019YFG0048)。

摘　　要：为研究高烈度强震区各种墩高典型公路简支梁的抗震性能,以某8度地震区高速公路典型10~40 m墩高公路简支梁为研究对象,采用一种核密度估计(KDE)的桥梁易损性分析法开展不同墩高桥梁地震易损性分析。利用OpenSees软件建立各种典型墩高桥梁全桥有限元模型。考虑桥梁结构参数与地震动输入的不确定性,通过时程分析获得各墩高对应桥梁各构件的最大动力响应。运用核密度估计的桥梁地震易损性分析方法建立不同墩高公路桥梁的易损性曲线,对比研究不同墩高对桥梁各关键构件在地震作用下的易损性能及其差异性,研究8度和9度罕遇地震时各墩高桥梁关键构件在4种损伤状态下对应的地震易损性分布特征。研究结果表明:汶川地震作用下10~40 m墩高典型公路简支梁桥墩抗震性能良好,支座比桥墩更易损,随着桥梁墩高的增加,支座越容易发生地震损伤破坏,建议墩高超过40 m的桥梁采取减震耗能、限位措施,限制主梁发生过大位移,提高桥梁抗震性能。建立的地震易损性曲线可用于评估各种墩高典型公路简支梁桥梁的抗震性能,并为类似高烈度地震区公路简支梁桥抗震设计提供依据。To find out the seismic performance of the highway simply supported girder bridge with different height of the pier in high seismicity region,this paper considered the highway simply supported bridges with pier height from 10 m to 40 m in 8 magnitude earthquake area as the research object.The bridge seismic vulnerability analysis method based on kernel density estimation(KDE)was used to analyze the seismic vulnerability of bridges with different pier heights.The bridge finite element models were established by using the software OpenSees.Considering the uncertainty of the earthquake excitation and the structural parameters,the maximum dynamic response of each key members of the bridge with different pier heights were obtained from the nonlinear time history analysis(i.e.,incremental dynamic analysis procedure).The fragility curves of bridge dangerous members were obtained by using the bridge seismic vulnerability analysis method based on kernel density estimation.The differences of seismic vulnerability of the bridge components with different pier heights were compared and studied.The seismic vulnerability distribution characteristics of key components of bridges with different pier heights under four damage states in rare earthquakes of 8 degree and 9 degree were studied.The results show that the simply supported bridge with different pier heights under Wenchuan earthquake have good seismic performance.The bearings are more vulnerable than the piers.When the pier is higher,the bearing is more prone to damage and destruction.It is suggested that the bridge with pier height more than 40 m should be equipped with the dampers and the limiting measures to inhibit the excessive displacement of the main beam and improve the seismic performance of this kind of bridge.The vulnerability curve can be used to evaluate the seismic performance of highway simply supported bridges with different pier heights and provide the basis for the seismic design of typical highway bridges.

关 键 词：公路简支梁桥 地震易损性 不同墩高 核密度估计 

分 类 号：U448.23[建筑科学—桥梁与隧道工程] U442.55[交通运输工程—道路与铁道工程]