天津海河开启桥空腔薄壁墩施工技术

Construction Technology for Thin-walled Cavity Pier of Tianjin Haihe River Movable Bridge

天津海河开启桥是亚洲同类最大跨度开启桥,主墩为异形空腔薄壁钢筋混凝土结构,内部安装机械、液压、电控等高精密开启设备,墩身为薄壁空腔结构,混凝土的防腐、抗冻、抗渗要求高。为保证墩身混凝土施工质量,研究了相应的施工控制技术,主要包括墩身先浇段和后浇段混凝土配合比设计,混凝土分层分段浇筑方案,及加钢边橡胶止水带、利用免拆金属模板网及加强混凝土的养护等墩身裂缝控制技术措施,成功解决了大型空腔薄壁混凝土结构的裂缝问题,取得了满意的施工质量控制效果。

Tianjin Haihe river movable bridge is the largest span bridge in Asia.The main piers are special-shape thin-walled cavity reinforcement concrete structure,which has some precise opening equipment of machine,hydraulic and electronic control apparatus.So that,high performance concrete of anticorrosion,antifreeze and permeability is needed.To ensure the construction quality of concrete pier,the authors research some corresponding technologies such as mix proportion design of before and later poured concrete,layered and segmented concrete pouring scheme,and some crack control technologies of adopting rubber waterproofing strips with steel rim and free-dismantled metal formwork nets,and strengthening concrete curing,which can achieve the desired goal of quality control.