悬吊式桥面系吊杆拱桥的梁桥体系改造技术  

Transforming a Suspended Deck System to a Continuous Girder System for Basket-Handle Arch Bridge

作　　者：贺果蒙 朱世峰 刘昂 韩永平 HE Guo-meng;ZHU Shi-feng;LIU Ang;HAN Yong-ping(Sichuan Chengyu Expressway Co.,Ltd.,Chengdu 610041,China;CCCC Road&Bridge Special Engineering Co.,Ltd.,Wuhan 430071,China;National Engineering Research Center for High-Efficiency Maintenance and Safety and Durability of Highways and Bridges(Wuhan),Wuhan 430071,China)

机构地区：[1]四川成渝高速公路股份有限公司,四川成都610041 [2]武汉二航路桥特种工程有限责任公司,湖北武汉430071 [3]公路与桥梁高效养护及安全耐久国家工程研究中心,湖北武汉430071

出　　处：《桥梁建设》2022年第6期147-154,共8页Bridge Construction

基　　金：国家自然科学基金项目(51778094);交通运输行业重点科技项目(2021-ZD1-035);内蒙古自治区交通运输厅建设科技项目(NJ-2021-09)。

摘　　要：成渝高速公路新龙坳立交桥主桥为单孔跨径120 m(净跨117.80 m)的交叉吊杆中承式混凝土提篮拱桥,采用悬吊式桥面系。该桥1995年建成通车,2006年曾进行加固改造,2017年全桥检查发现存在横梁间限位梁牛腿破损严重、混凝土构件开裂、加固用钢板及吊杆下锚头锈蚀等病害,需再次维修加固改造。为提高桥梁安全性、降低后续维护成本、确保桥下铁路运营安全,结合结构病害和桥位处环境,提出悬吊式桥面系拱桥的连续梁桥体系加固改造技术。在原混凝土横梁两端顺桥向各增设5个独柱式桥墩和1道钢桁纵梁,钢桁纵梁通过桥下顶升与原横梁共同受力实现体系转换,将悬吊式桥面系吊杆拱桥主跨部分变为(21.3+2×25.5+21.3)m四跨空间框架连续梁体系。为了解改造后的桥梁性能,采用MIDAS Civil软件建模,进行改造后桥梁的整体与钢桁纵梁局部受力性能数值分析,并进行全桥荷载试验。结果表明:改造后桥梁各构件受力均满足规范要求,桥梁具备较高的安全储备。The main bridge of Xinlongao Interchange is a network,half-through,concrete basket-handle arch bridge that spans 120 m(net span length of 117.8 m).The deck system is a suspended system.The bridge was opened to traffic in 1995 and experienced a strengthening in 2006.However,the inspection of 2007 still revealed multiple deteriorations in the bridge,including the severe damage of brackets attached to the restrainer beams between the crossbeams,concrete components cracking,corrosion of steel plates for strengthening and corrosion of lower anchor heads of suspenders.As such,another rehabilitation was needed.To improve the safety of the bridge,reduce the subsequent maintenance costs and ensure the operation safety of the railways below,taking into account the structural deteriorations and environments at the bridge site,it was determined to transform the original suspended deck system to a continuous girder system.The specific rehabilitation work included adding five mono-column piers and one steel truss stringer to each end of the original concrete crossbeams along the bridge length,the steel truss stringer was jacked up from below to carry loads together with the original crossbeams to realize system transformation.The main span of the original basket-handle arch bridge with a suspended deck system was transformed to be a spatial continuous lattice girder system,with two end spans of 21.3 m and two main spans of 25.5 m.To examine the load bearing capacity of the bridge after rehabilitation,a finite element model was developed in MIDAS Civil to carry out numerical analysis of the overall bridge as well as the local loading condition of the steel truss stringer.Load test was conducted for the overall bridge.The results demonstrate that the components of the bridge after rehabilitation achieve the code requirements,and the bridge has larger safety margin.

关 键 词：吊杆拱桥 跨线桥 悬吊式桥面系 梁桥体系改造 钢桁纵梁 体系转换 改造施工 

分 类 号：U448.22[建筑科学—桥梁与隧道工程] U445.6[交通运输工程—道路与铁道工程]