马鞍山长江大桥钢箱梁合龙施工牵引预偏关键技术

发布时间：2018-04-01 07:52

本文选题：悬索桥　切入点：钢箱梁　出处：《世界桥梁》2014年02期

【摘要】：马鞍山长江大桥左汊主桥为(360+2×1 080+360)m三塔两跨悬索桥,加劲梁为流线型扁平钢箱梁,采用塔梁固结体系。研究确定采用4台跨缆吊机,从两主跨跨中往桥塔方向进行钢箱梁节段吊装。采用有限元法建立平面杆系模型,进行合龙仿真计算,得到不同条件下合龙所需牵拉力,根据该结果进行牵引预偏系统设计,经方案比选确定采用千斤顶牵引已吊装梁段预偏的方案实现合龙。合龙施工时,在上、下游塔肢各配1台300t千斤顶,每台配12束鐖s15.2高强度低松弛预应力钢绞线,在塔柱位于桥面以上的人孔内插入悬挑梁,作为千斤顶支撑座;跨缆吊机垂直起吊合龙段,至其顶与已吊装梁段底之间的净距在20~30cm时,利用牵引预偏系统牵引梁段,增大合龙空间,完成合龙段施工。
[Abstract]:The main left branch bridge of Ma'anshan Yangtze River Bridge is a two-span suspension bridge with three pylon span of 360m 脳 1080,360m, and the stiffened beam is a streamlined flat steel box girder with a tower beam consolidation system.Four cable cranes are used to hoist the steel box girder from the middle of two main spans to the bridge tower.The finite element method is used to establish the plane bar system model, and the simulation calculation of the closure is carried out, and the pull force required by the closure is obtained under different conditions. According to the results, the traction prebias system is designed.According to the scheme comparison and selection, the scheme of pre-deviation of hoisting beam section is adopted to realize closure.In closing construction, the upper and lower reaches are equipped with one 300t Jack each, each equipped with 12 bundles of s15.2 high strength and low relaxation prestressed steel strands, and a cantilever beam is inserted into the manhole above the bridge deck to be used as the Jack support seat.When the net distance between the top of the crane and the bottom of the hoisting beam section is 20~30cm, the traction prebias system is used to draw the beam segment to increase the closing space and complete the construction of the closure section.
【作者单位】：中交二公局第五工程有限公司;
【分类号】：U448.25;U445.4

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