沪昆高铁北盘江特大桥合理结构形式研究

Study on Reasonable Structure for Beipanjiang Bridge on Shanghai-Kunming High-speed Railway

沪昆高速铁路北盘江特大桥为跨越北盘江峡谷而设,桥面距离谷底约300 m,峡谷宽约720 m,为使桥梁满足设计最高行车速度350 km/h使用功能要求,设计选择了结构整体刚度大且后期变形相对较小的上承式钢筋混凝土拱桥结构。本文以桥梁设计的安全、经济、适用、美观为结构设计的主要原则,以北盘江特大桥为工程背景,从主拱矢跨比及主跨的选择、交界墩处设置大跨的原因、拱上结构体系及优化和拱座结构形式的对比分析等方面,研究和探讨了艰险山区高速铁路大跨度上承式混凝土拱桥的合理桥跨布置及合理结构形式,可为以后同类设计提供重要参考。

Beipanjiang bridge on Shanghai-Kunming high-speed railway is designed to cross the Beipanjiang valley.The bridge deck is about 300 m high from the bottom of valley,the valley width is about 720 m.To meet the requirement of design maximum speed of 350 km/h,reinforced concrete deck type arch bridge is chosen because of its large whole stiffness and relatively small deformation in later period.Based on this bridge,in view of safety,economy,application and aesthetics,the reasonable structure and layout of long-span reinforced concrete deck type arch bridge on high-speed railway are studied and discussed from the aspects of arch rise-span ratio,main span selection,setting large span at juncture pier,spandrel structure system and skewback structure,etc.All these results can provide important references for similar design in the future.