川藏铁路简支梁桥地震易损性及适应性分析  

Analysis of Seismic Vulnerability and Adaptation of Simply- supported Girder Bridge on Sichuan- Tibet Railway

作　　者：杨平[1] 杨国静[1] 曾永平[1] 

机构地区：[1]中铁二院工程集团有限责任公司,成都610031

出　　处：《铁道工程学报》2015年第12期51-57,75,共8页Journal of Railway Engineering Society

摘　　要：研究目的:震害表明,铁路桥梁作为交通系统中的枢纽结构在地震中极易受损。在建的川藏铁路穿越甘孜炉霍地震带和雅鲁藏布江地震带,地震设防烈度均在8度以上。本文以铁路桥梁中常见结构形式32 m跨简支梁桥为研究对象,采用汶川地震波,以位移延性比为破坏指标,对不同墩高的32 m跨简支梁桥进行易损性和适应性分析,为川藏铁路桥梁的抗震设计提供参考和依据。研究结论:(1)地震易损性分析结果表明:就川藏铁路桥梁墩高从3 m到40 m而言,25 m墩高的桥墩损伤概率最大,当地面峰值加速度为0.35g时,对应的轻微破坏概率为18%,说明桥墩抗震性能较好;(2)适应性分析结果表明:各种墩高的桥墩抗震性能相对较好,4种损伤状态中,轻微破坏和中等破坏的曲线较为接近,中等破坏和严重破坏的曲线离得较远,结构具有相对较好的延性能力;(3)本研究成果对于进一步完善西南山区铁路桥梁的抗震设计、震后紧急响应以及桥梁结构的评估等具有指导意义。Research purposes： Seismic damage reveals that railway bridges, the key structures in the transportation system, are vulnerable to earthquakes. The under- construction Sichuan -Tibet Railway will pass the Luhuo Earthquake Zone and the Yarlung Zangbo Earthquake Zone, and are thus designed to withstand 8.0 -magnitude earthquakes. The paper has analyzed the vulnerability and adaptability of 32 m - span simply - supported girder railway bridges of a typical structure and different pier heights in accordance with the Wenchuan Seismic Wave and the displacement ductility ratios as failure indexes, hoping to provide theoretical references and a basis for the anti - earthquake design of the bridges along the Sichuan - Tibet Railway. Research conclusions： （ 1 ） Analysis of seismic vulnerability indicates that ： Sichuan - Tibet Railway bridges supported by 3 m - 40 m high piers can better resist earthquakes, and the slight damage probability is 18% when the peak acceleration of ground oscillation is 0.35g, except for those supported by 25 m - high piers that are most likely to be damaged in an earthquake. （2） Analysis results of adaptability indicates that ： all piers, regardless of their height, have relatively good anti - seismic properties. Among the four damages shown in curve graphs, the slight and moderate damages are close to each other, and the moderate and severe damages are far from one another, indicating that the structure is ductile. （3）The research result has guiding significance to improve further anti - seismic designs, post - earthquake emergency response and bridge structure evaluation of railway bridges in southwest mountainous areas.

关 键 词：铁路桥梁 地震易损性 适应性 增量动力分析 位移延性比 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]