V型墩刚构桥自平衡组合支护体系设计与施工  

Design and Construction of a Self-Balancing Composite Shoring System for Rigid-Frame Bridge with V-Shaped Piers

作　　者：徐爱敏 王东妹 张杰 XU Aimin;WANG Dongmei;ZHANG Jie(Ningbo High-Grade Highway Construction Management Center,Ningbo 315192,China)

机构地区：[1]宁波市高等级公路建设管理中心,浙江宁波315192

出　　处：《世界桥梁》2024年第5期24-29,共6页World Bridges

摘　　要：宁波舟山港六横公路大桥梅山水道跨堤桥为(60+100+60)m V型墩刚构桥,主梁采用预应力混凝土箱梁,主墩为V型墩。针对该桥施工重难点,提出一种自平衡组合支护体系进行V型墩和0号块施工。该体系由临时支架系统和拉杆系统组成,临时支架系统包括V型墩外侧支架和0号块中部支架两部分,在墩身竖直方向设置3层拉杆,每层布置5根拉杆。有限元计算结果表明:V型墩和0号块施工时支护体系受力满足要求,待主梁合龙后方可拆除V型墩外侧支架和墩身拉杆,4号梁段预应力施工完后方可拆除0号块中部支架。承台施工完成后,安装V型墩外侧支架及拉杆系统,墩身采用滑槽一次浇筑成型,拉杆分3个阶段张拉;V型墩施工完后安装0号块中部支架,0号块混凝土采用汽车泵分2次浇筑完成,拉杆分4个阶段张拉;0号块施工完成后进行主梁挂篮悬浇施工,支护体系按计算确定的拆除时机拆除。主梁施工完成后,墩身线形良好,墩底内、外侧及0号块箱梁内、外均无裂缝产生。The Meishan Waterway Embankment-Crossing portion of Liuheng Highway Bridge at Zhoushan Port,Ningbo is a rigid-frame bridge with a main span of 100 m and two side spans of 60 m.The superstructure consists of prestressed concrete box girders supported on V-shaped piers.During the construction of the bridge,a self-balanced composite shoring system composed of a temporary shoring system and a tie-rod system was developed specially for the erection of V-shaped piers and pier-top girder segments.The temporary shoring system includes the falsework installed around the V-shaped piers and the falsework installed in the center of the pier-top girder segment.Tie rods were arranged at three elevations along the vertical direction of the pier,five ones at each elevation.The numerical modelling indicated that the load bearing performance of the shoring system during the construction of the V-shaped piers and pier-top girder segments meet the requirements.The falsework around the V-shaped piers and tie rods connected to the piers can be dismantled after the closure of the superstructure,while the falsework in the center of the pier-top girder segment after the implementation of the prestress in the girder segment No.4.After the construction of the pile caps,the falsework around the V-shaped piers and tie rods were installed,the piers took shape by one-off cast with the aid of chutes,and the tie rods were tensioned at three stages.After the construction of the V-shaped piers,the central falsework for the pier-top girder segment was installed,and the pier-top girder segment was cast at two times using the mobile pumps.The tie rods were tensioned four times.After the casting of the pier-top girder segment,the cantilever casting of the remaining girder segments using the form travelers began.The shoring system was dismantled according to the numerical simulation.After the completion the main girders,the piers were in good alignment,no cracks were observed in the surfaces and bottom of piers,and pier-top segment as well.

关 键 词：刚构桥 V型墩 自平衡组合支护体系 临时支架系统 拉杆系统 施工技术 

分 类 号：U448.23[建筑科学—桥梁与隧道工程] U445.35[交通运输工程—道路与铁道工程]