悬臂浇筑法中劲性骨架段的合理长度

悬臂浇筑与劲性骨架组合施工法是一种新型的钢筋混凝土拱桥施工方法,相较于悬臂浇筑施工,不仅可以缩短拱圈悬臂浇筑段的长度,减轻悬臂的质量,降低对扣锚系统的要求,而且能够尽快形成拱结构,从而减少施工风险,缩短工期,提高钢筋混凝土拱桥的经济性。从主拱圈自身受力特点、扣索力的利用效率、施工过程最大扣索力、拱圈拉应力等几个方面分析了悬臂浇筑与劲性骨架组合法中劲性骨架段合理长度的选取。结果表明劲性骨架段长度取跨度的0.38~0.54倍最为合理。

Reasonable Length of Stiff Skeleton Segment of Cantilever Casting Method

The combined construction method of cantilever casting and stiff skeleton is a new construction method of reinforced concrete arch bridge.Compared with cantilever casting construction it can not only shorten the length of cantilever casting segment of arch ring lighten the weight of cantilever casting segment and reduce the requirement of anchoring system but also can form arch structure as soon as possible thus reduce construction risk shorten the project time and improve the economic benefit of reinforced concrete arch bridge.The selection of the reasonable length of the stiff skeleton segment of the combined method of cantilever casting and stiff skeleton was analyzed comprehensively from the stress characteristics of arch ring he utilization efficiency of cable force the maximum cable tension and tensile stress of arch ring in the construction process.The results show that the most reasonable lengthofthestiffskeletonsegmentis0 38~0 54timesofthespan.