轨道交通大跨度预应力混凝土连续梁桥加固设计  

Retrofit Design of Long-Span Prestressed Concrete Continuous Light Rail Bridge

作　　者：褚文涛[1] 关进轩 杨帆[1] 吕宏奎 CHU Wen-tao;GUAN Jin-xuan;YANG Fan;LYU Hong-kui(China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China;China Railway Bridge Science Research Institute,Ltd.,Wuhan 430034,China)

机构地区：[1]中铁大桥局集团有限公司,湖北武汉430050 [2]中铁大桥科学研究院有限公司,湖北武汉430034

出　　处：《世界桥梁》2023年第S01期159-166,共8页World Bridges

基　　金：中国中铁股份有限公司重点开发计划项目(2016-重点-12)。

摘　　要：针对轨道交通大跨度预应力混凝土连续梁桥跨中下挠及开裂等病害,以某轨道交通(65+120+65)m预应力混凝土连续梁桥为背景,研究该类病害桥梁加固方法。根据资料调研及有限元计算,对受损主梁进行病害成因分析及状态模拟。经过方案比选,确定加固方案为:补充张拉2束15-∅15.2 mm备用体内预应力束;增设12束19-∅15.2 mm体外预应力束;预应力管道补充注浆、裂缝封闭。施工监测结果显示:加固后主梁中跨跨中截面增加了5.73 MPa压应力、上拱22.3 mm。加固后轨道交通恢复正常速度通行,监测结果表明桥梁轨道平顺、行车舒适度良好,证明了加固方案安全适用、效果显著。The retrofit techniques to address the deteriorations,such as midspan deflection and cracking of the long-span prestressed concrete continuous light rail bridge are the study focus of this paper.An existing bridge of such type,which has a main span of 120 m and two spans of 65 m,is used as a case.Literatures were reviewed and finite element calculation was carried out to analyze the causes of main girder deteriorations and simulate the state of the bridge.By the selected retrofit solution,12,19-∅15.2 mm external prestressing tendons were added to the bridge,two backup internal prestressing tendons of 15-∅15.2 mm were tensioned for supplementation.The conduits of prestressing tendons were grouted for remedial and cracks were sealed.The construction monitoring results demonstrate that after retrofit,the compressive stress and precamber of the midspan cross-section of the main girder is increased by 5.73 MPa and 22.3 mm,respectively.After retrofit,the service speed of the light rails restores to normal.The health monitoring results show that the rails of the bridge are smooth,with good riding comfort,which proves that the proposed retrofit solution is efficient and suitable for the long-span prestressed concrete continuous light rail bridge.

关 键 词：轨道交通 连续梁桥 病害 预应力束 补充注浆 裂缝封闭 加固设计 监测 

分 类 号：U448.215[建筑科学—桥梁与隧道工程] U445.72[交通运输工程—道路与铁道工程]