晋陕黄河特大桥2×108m单T刚构挂篮设计

Design of 2×108 m Single T Rigid Frame Movable Suspended Scaffold for Shanxi-Shaanxi Yellow River Bridge

研究目的:大(同)西(安)铁路客运专线晋陕黄河特大桥主桥采用15联2×108 m单T刚构钢桁加劲组合结构形式,为国内首次运用,箱梁采用单箱双室、变高度、变截面结构且节段数量多、重量大,T构悬臂段施工方法为在0#块上拼装挂篮之后对称浇筑。为了保证2×108 m T构安全高效施工,必须设计一套能承重节段重量且自身重量较轻的挂篮来配合施工。研究结论:晋陕黄河特大桥2×108 m T构采用三幅双拼菱形桁架形式作为主受力构架。(1)杆件均能满足受力要求,底模平台吊挂系统最大变形量11.3 mm,内、外滑梁及吊挂最大变形量7.2 mm,前上横梁及菱形构架最大变形量25.1 mm,后锚固系统最大变形量1.7 mm,挂篮杆件受力及变形均在允许范围之内,满足施工需要;(2)挂篮自重较轻,可减少挂篮加工的资金投入;(3)操作简单,在保证安全质量的同时可加快施工进度;(4)可为类似T构、连续梁施工的挂篮设计提供借鉴。

Research purposes： The structure of 15 spans 2 × 108 m single T rigid frame steel truss was used for the main bridge of Shanxi - Shaanxi Yellow River of the Datong - Xi＇an Passenger Dedicated Line and it was used in China for the first time. The single box and double chamber structure with various heights and sections, many segments and heavy weight was used for the box girder. The symmetrical pouring was conducted in the sections of the T rigid frame cantilever after the suspended scaffold was assembled on the piece 0 #. To ensure the safe and high - efficient construction of the 2× 108 m T rigid frame, the movable suspended scaffold with less weight and being able to bear the load of the heavy segment had to be designed for cooperating with the construction. Research conclusions：The tri -piece and double assemble rhombus truss structure was used for the 2 × 108 m T rigid frame as the main frame to bear the load. （ 1 ） The member bar met the requirement of the load bearing, the maximum deformation of the suspending system on the bottom die platform was 11.3 mm, the maximum deformations of the internal and external sliding girders and suspension were 7.2mm, the maximum deformations of the front top cross girder and rhombus truss structure were 25.1 mm, the maximum deformation of the rear anchorage system was 1.7 mm and the load bearing and deformation of the member bar of the suspended scaffold was in allowable range. All these met the requirements. （2） The suspended scaffold weight was less and it could save the cost. （3） It was easy to operate and it could speeded up the construction process on the premise of ensuring the construction quality. （4） It could provide the reference to the similar works.