斜拉桥主梁大型0号块施工技术  

Construction Techniques for Massive No.0 Main Girder Block of Cable-Stayed Bridge

作　　者：付浩[1] 严杰[1] 尹振君[1] 潘立泉[2] 

机构地区：[1]中铁大桥局集团第五工程有限公司,江西九江332004 [2]中铁大桥局集团桥科院有限公司,湖北武汉430034

出　　处：《世界桥梁》2015年第3期33-37,共5页World Bridges

摘　　要：武汉西四环汉江特大桥主桥为(77+100+360+100+77)m预应力混凝土梁斜拉桥,主梁为π形结构,两边为单箱双室、中间为纵横梁加桥面板结构形式。主梁0号块宽44m、长22m,采用钢管桩贝雷梁支架现浇施工。支架由底模系统、横梁(贝雷梁)、桩顶分配梁、砂筒、钢管支架组成,支架施工完后采用反力架预压钢管桩,边箱室顶板底模采用透水模板布施工。通过混凝土配合比优化,配制高耐久性、稳定性的C55高性能混凝土,并采用天泵和地泵从两个方向分层浇筑,桥面纵、横坡采用提浆整平机控制。在0号块混凝土强度成长期预张拉横向预应力,纵向预应力待1号和1′号块施工完采用连接器连接构成整束一次性张拉;预应力采用智能张拉系统张拉、智能压浆系统压浆。实践表明,该桥采用该施工技术成功克服了支架不均匀沉降,有效控制了裂纹的产生,保证了主梁0号块的施工质量与施工安全。The main bridge of the Hanjiang River Bridge on the west Fourth Ring Road in Wu- han is a prestressed concrete girder cable-stayed bridge with span arrangement of （77＋100＋ 360＋ 100＋77） m. The two edge boxes （two：cell single box structure） together with the central lattice beam covered with deck slabs form the π-shaped main girder. The No. 0 block of the main girder, cast on scaffolds made up of steel pipe piles and bailey trusses, is 44 m wide and 22 m long. The scaffolds are composed of the chassis, floor beam （bailey truss）, pile-top distributive beam, sand bailer and steel pipe supports. After the completion of the construction of the scaffolds, the steel pipe piles were pre-compressed using reaction frame, and the chassis for the top plate of edge boxes are constructed by using permeable formwork cloth. During the concreting, the concrete mixing proportion was optimized, the C55 high-performance concrete with sound durability and stability was prepared, and the layered casting of the truck-mounted pump and the trailer pump proceeded from two directions. Longitudinal and transverse deck slopes were controlled by the leveling ma- chine. During the strength growth of the concrete in the No. 0 block, the transverse prestressing tendons were pre-tensioned. After the construction of the No. 1 and No. 1＇ blocks was finished, the longitudinal prestressing tendons were linked to a whole bundle by connectors and tensioned only once. The prestressing tendons were tensioned by intelligent tensioning system and grouted by the intelligent grouting system. The engineering practice proves that by using the construction techniques, the unbalanced settlement of the scaffolds was successfully controlled, cracking was also effectively overcome, and the construction quality and safety of the No. 0 block of the main girder was guaranteed.

关 键 词：斜拉桥 π形梁 预应力混凝土结构 主梁0号块 支架 透水模板布 高性能混凝土 预应力 施工技术 

分 类 号：U448.27[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]