银西高速铁路拱加劲连续钢桁梁结构设计

Design of Arch Stiffening Continuous Steel Truss on Yinchuan-Xi'an High Speed Railway

依据防洪评价报告,银西高铁银川黄河特大桥跨越黄河主河槽最小跨径需160 m以上。文章从美观、造价、施工难易度、结构受力分析等方面综合比较分析了平行弦连续钢桁梁、变高弦连续钢桁梁、拱加劲连续钢桁梁3种设计方案的优缺点,最终推荐采用3×168 m等跨拱加劲连续钢桁梁结构跨越黄河主河槽方案。介绍了该方案的设计要点、组合结构的受力规律、结构的刚度、材料用量及施工方案,通过增加拱肋的方式,大大增加了结构的刚度,使每孔结构的受力规律与简支结构类似,改善结构的受力条件,克服等跨布置受力缺陷。该桥在施工及运营阶段的刚度、强度均满足规范要求,具有良好的动力特性,为同类桥梁的设计施工起借鉴作用。

According to flood control evaluation report, the minimum span of Yinchuan Yellow River Bridge on Yinchuan-Xi＇an high speed railway across the Yellow River main river channel shall be more than 160 m. The design uses a 168 m span continuous structure across the main river channel. This paper compares the merits and demerits of three designing schemes such as parallel chord continuous steel truss girder,truss high variability continuous steel truss girder and arch stiffening continuous steel trussfrom the aesthetics,cost,difficulty of construction,structural stress analysis and other factors,finally 3 × 168 m equal span stiffening chord continuous steel truss girder is recommended.Then the design point of the program,the forced law of composite structure,stiffness of the structure,the amount of material and construction programs are introduced. The results show that the bridge meets regulatory requirements of stiffness and strength in the construction and operation by adding the arch ribs. The bridge has a good dynamic characteristics,design and construction of similar bridges from reference.