曲线匝道箱梁桥现浇施工中支架布置形式分析

Analysis of Scaffold Arrangement in Cast-in-situ Construction of Curved Ramp Box Girder Bridge

支架现浇施工在桥梁工程中运用广泛,但在曲线匝道箱梁桥支架现浇施工中仍存在施工难点,导致支架安全事故频发。针对曲线匝道箱梁桥固定支架整体就地浇筑施工过程中支架受力不均匀问题,总结了三种曲线箱梁桥支架布置方式,以不同支架布置方式、不同桥宽、不同曲率的Midas/Civil曲线匝道箱梁桥有限元模型为对象,通过对比分析不同模型计算所得内外两侧支架反力差数据的方式,比较了不同支架布置形式的优缺性,并研究了三种布架方式中轴线平行式布架方式下支架受力的影响因素,在此基础上探讨如何选取合适的支架布置方案以满足支架系统受力要求与施工便捷性要求。结果表明:轴线平行式布架方式在支架受力方面安全性能较高、施工可行性强。轴线平行式布架方式下内外侧支架反力差受桥宽及分段数量影响。提出了轴线平行式布架方式在不同桥宽下的合理分段范围。

Support cast-in-situ construction is widely used in bridge engineering.However,the construction difficulties in cast-in-situ construction of curved ramp box girder bridge lead to frequent support safety accidents.Aiming at the problem of uneven force on the scaffolds during the integral cast-in-place construction of fixed support of curved ramp box girder bridge,three curved box girder bridge scaffolds arrangements were summarized.The Midas/Civil curved ramp box girder bridge finite element models with different scaffolds arrangements,different bridge widths and different curvatures were used as research objects.By comparing and analyzing the data of reaction force on inner and outer scaffolds calculated by different finite element models,the advantages and disadvantages of different scaffold arrangements were analyzed.The influence factors of the force on scaffolds under the axis-parallel arrangement among three scaffold arrangements were studied.On this basis,the method of selecting reasonable scaffold arrangement was discussed to meet the stress requirements of support system and construction convenience requirements.It is found that the axis-parallel arrangement method is suitable in terms of support load and construction feasibility.The reaction force difference between the inner and outer scaffolds under the axis-parallel arrangement is affected by the bridge width and the number of sections.The reasonable segmentation range of the axis-parallel arrangement method under different bridge widths is proposed.