棋盘洲长江公路大桥上部结构施工技术

棋盘洲长江公路大桥主桥为(340+1038+305)m的双塔单跨钢箱梁悬索桥,桥塔采用门形框架式结构,加劲梁采用钢箱梁,单根主缆由101股通长索股组成,吊索与索夹和钢箱梁采用销铰式连接。主索鞍采用分块安装方式,利用塔顶门架、卷扬机、滑车组配合起吊至塔顶,通过倒链配合在塔顶门架上横移安装到位。主缆采用PPWS法架设,利用卷扬机沿猫道面牵引索股,期间通过调整索股保证主缆线形。钢箱梁安装采用全液压缆载吊机小节段吊装方案,全桥共65个吊装梁段,从主跨跨中对称向桥塔方向进行安装,在桥塔附近各设1个合龙段。浅滩岸坡区部分梁段采用支架和荡移方式安装。施工监控结果表明,桥面标高满足设计要求,成桥线形精度较高。

Construction Techniques for Superstructure of Qipanzhou Changjiang River Highway Bridge

The main bridge of Qipanzhou Changjiang River Highway Bridge is a suspension bridge with three spans of 340,1038 and 305 m.The two towers are portal-frame structures,the stiffening girder consists of steel boxes and each main cable contains a number of 101 full-length strands.The hanger cables only suspend the central span,which are pin-connected with the cable clamps and the steel box girder.The components of the main cable saddles were hoisted onto the top of the tower by the gantry crane mounted on the tower top,winches and pulleys,assembled piece by piece,transversely moved on the gantry crane and lowered into position with the aid of chain blocks.The main cables were erected by PPWS method,and the strands were dragged forward along the floor of the catwalk by winches and were adjusted during the dragging process to ensure the geometry of the main cable.The 65 steel box girder segments were installed by the hydraulic main cable supported cranes from the midpan of the main span towards the towers,and the closure gaps were set near the towers.The girder segments over the shoal area and the bank slopes were installed by scaffold method and swing method.The results of the construction monitoring and control indicate that the elevation of the bridge deck meets the requirements and the geometry of the bridge after completion is of high accuracy.