钢箱梁建设过程中最优支撑间距设置的研究

Study on Optimum Spacing of Supports in Construction of Steel Box Girders

钢箱梁建设过程中支撑间距设置的越密,越有利于桥梁结构的内力及线形控制,但是位于长江行洪区的桥梁不可避免的要面临防洪防汛的要求,支撑间距不能设置的过密,为此,本文以长江岸边某环形景观桥为背景,使用Midas Civil软件建立桥梁有限元模型,分析了不同桥跨、不同支撑间距时钢箱梁的结构位移和截面应力,以寻求钢箱梁建设过程中最优化的支撑间距设置。研究发现:支撑间距与钢箱梁的结构位移和截面应力呈正相关;当桥跨较小时可采用一跨跨越的方式进行施工;当桥跨超过47.5 m时,必须增设支撑,以保障钢箱梁结构受力安全性。

The closer the spacing of supports in the construction of steel box girder,the better the control of internal forces and alignment of bridge structure.However,the bridge located on the flood way of the Yangtze River inevitably faces the requirement of flood control,thus the supports cannot be closer to each other.Based on a circular landscape bridge along the Yangtze River,MIDAS Civil software is used to build a finite element model to analyze the structural displacement and section stress of steel box girder with different spans and supports spacing,and calculate the most optimal support spacing in the construction of steel box girder.It is found that the structural displacement and section stress of steel box girders will increase with the increment of supports spacing.One-span bridge applies to the bridge with smaller span.When the bridge span exceeds 47.5 m,more supports shall be added so as to ensure the structural safety and stress of steel box girder.