芜湖长江公铁大桥南引桥铁路梁斜腿支架现浇施工技术  

Construction Technique of Casting Prestressed Concrete Box Girders on Outrigger Scaffolds for Railway Deck of South Approach Bridge of Wuhu Changjiang River Rail-cum-Road Bridge

作　　者：方柯[1,2] 刘爱林 王令侠 FANG Ke;LIU Ai-lin;WANG Ling-xia(China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China;State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China;Project Management Office of Wuhu Changjiang River Rail-cum-Road Bridge on Shangqiu-Hefei-Hangzhou Railway,China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhu 241001,China)

机构地区：[1]中国中铁大桥局集团有限公司,湖北武汉430050 [2]桥梁结构健康与安全国家重点实验室,湖北武汉430034 [3]中铁大桥局商合杭铁路芜湖长江公铁大桥项目经理部,安徽芜湖241001

出　　处：《桥梁建设》2020年第6期116-121,共6页Bridge Construction

基　　金：中铁大桥局集团有限公司科学技术研究与开发项目(2015-02-重大)。

摘　　要：商合杭铁路芜湖长江公铁大桥南引桥5~E4号墩下层铁路梁采用双幅4×40.7 m预应力混凝土简支梁结构,单片梁重约1250 t。墩位处软弱覆盖层厚度达28.2 m,铁路梁底距河床面(地面)最高达60.186 m,5~E2号墩铁路梁正下方设有大型临时设施。根据工程特点和难点,该南引桥下层铁路梁采用“斜腿支架现浇+横移”法施工。斜腿支架采用墩旁立柱、跨中斜柱和单层贝雷梁的结构体系,仅在单幅搭设。其中墩旁立柱及跨中斜柱均落于桥墩承台,跨中不设临时桩;贝雷梁按3跨连续布设。采用有限元法分析斜腿支架受力,结果表明斜腿支架结构合理,各杆件受力满足要求。施工中,通过采用工厂加工、合理确定安装顺序和预拱度等措施确保斜腿支架安装精度和成桥线形满足要求。In the Wuhu Changjiang River Rail-cum-Road Bridge on the Shangqiu-Hefei-Hangzhou Railway,the section of south approach bridge between piers 5-E4 contains twin simply-supported prestressed concrete box girder structures with four equal spans of 40.7 m,and the box girders in a single span weighs about 1250 t.The weak overburden at piers measures 28.2 m deep,and the maximum clearance from the base of railway deck to the river surface(or ground)reaches up to 60.186 m.The large-scale temporary construction facilities were deployed below the railway deck from piers 5-E2.Considering the characteristics of the project and the construction complexities,the method of casting prestressed concrete box girders on outrigger scaffolds and transverse moving was used for the railway deck of south approach bridge.The scaffolds,consisting of pier-side outriggers,midspan outriggers and single-level bailey trusses,were just arranged below one deck.Of which,the pier-side straight outriggers and midspan inclined outriggers all rested on the pile caps of piers,and no temporary piles were installed in the midspan.The bailey trusses were continuous in three spans.The load bearing behavior of the outrigger scaffolds was analyzed by finite element method.The results show that the configuration of the outrigger scaffolds was rational and the load bearing capacity of all the members could meet the requirements.During the construction,the members of the scaffolds were fabricated in the factory,rational installation sequence and precambers were determined to ensure the installation accuracy of the scaffolds and the bridge alignment in the complete state to meet the requirements.

关 键 词：公路铁路两用桥 预应力混凝土箱梁 斜腿支架 现浇施工 横移 施工技术 桥梁施工 

分 类 号：U448.121[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]