摘要
天津永和大桥为5孔一联、主跨260 m的双塔双索面PC斜拉桥,南、北辅助墩同时设置盆式橡胶压力支座和拉力摆支座。由于钢丝锈蚀和长期超载运营,拉力摆发生断裂,结构体系发生变化,进而引起南边跨合龙段下缘混凝土压溃、半数主梁预制节段接缝开裂、索力均匀性较差、主跨下挠、塔顶偏位的次生病害,采用更换拉力摆、加固边跨合龙段、调整斜拉索索力、补强主梁预制节段接缝等措施对结构体系进行恢复。施工监测结果表明桥跨结构的受力体系得以恢复。在最不利荷载组合下,新拉力摆具有足够的安全储备,主梁线形和塔顶偏位得到全面改善,斜拉索的索力安全系数满足现行规范的要求。
The Yonghe Bridge in Tianjin is a double-pylon and double-cable-plane prestressed concrete（PC） continuous girder cable-stayed bridge having five spans arranged in one continuous unit and a main span of 260 m.On the south and north auxiliary piers of the bridge,both the pot rubber compression bearings and tension rock bearings were installed.Owing to the steel wire corrosion and the long-term overload operation,the tension rocker bearing cables broke and the structural system changed,which in turn caused the secondary deteriorations like the concrete crushing at the lower edge of closure segment of the south side span,cracking of joints among half of the precast segments,poor uniformity of the stay cable forces,deflection of the main span and displacement of the pylon tops.The structural system of the bridge was rehabilitated and restored by replacing the tension rocker bearing cables,strengthening the closure segments of the side spans,adjusting the stay cable forces and reinforcing the joints among the precast segments of the main girder.The results of the construction monitoring showed that the force system of the bridge spans was restored and under the most unfavorable load combination,the replaced tension rocker bearing cables had sufficient safety reservation,the geometric shape of the main girder and the displacement of the pylon tops were completely improved and the safety factors of the stay cable forces could satisfy the current specifications.
出处
《世界桥梁》
北大核心
2011年第1期71-74,共4页
World Bridges
基金
交通部西部交通建设科技项目(200731822340)
关键词
斜拉桥
拉力摆支座
断裂
维修加固
恢复
cable-stayed bridge
tension rocker bearing
breaking
maintenance and strengthening
restoration
