重庆笋溪河大桥钢桁梁悬索桥设计

Design of Steel Truss Grider Suspension Bridge ofSunxi River Bridge in Chongqing

为适应桥位处的地形、地质、运输、场地等建设条件,经方案比选,重庆笋溪河大桥主桥确定为单跨660 m简支钢桁梁悬索桥。桥塔采用钢筋混凝土门式框架结构,两塔柱竖直布置,基础为分离式承台桩基础;大桥主缆由预制平行高强钢丝索股组成,吊索采用预制平行钢丝结构;加劲梁采用钢桁梁,桥面板为正交异性钢桥面板,板桁分离结构体系;两岸锚碇均为重力式锚碇,预应力锚固系统,基础为现浇扩大基础。本桥的重难点问题主要有大桥的抗风稳定性、主桥单向纵坡带来的不利影响、钢桁梁连接顺序、主塔横向不等高设计等,通过分析和研究该桥重难点问题,找到解决该问题的关键技术,为大桥的成功建成奠定了基础。

In order to adapt to the terrain,geology,transportation,site and other construction conditions,the main bridge of Sunxi River Bridge in Chongqing is determined to be a 660m single-span simply supported steel truss suspension bridge by schemes comparis on.The bridge tower is of reinforced concrete structure with portal frame and vertical tower columns,the foundation consists of a group of piles with separate pile cap.The main cable of the bridge adopts prefabricated parallel high-strength steel strand,and the sling adopts prefabricated parallel steel wire.The stiffening beam is steel truss beam,the deck is orthotropic steel deck,and the plate truss separation structure system.The anchorages on both sides are gravity anchorages with prestressed anchorage system and the foundation is cast-in-place expanded foundation.The key and difficult problems of this bridge mainly include the wind resistance stability of the bridge,the adverse effect of the one-way longitudinal slope of the main bridge,the connection sequence of steel truss girder,the design of the transverse unequal height of the main tower,etc.Through the analysis and research of the key and difficult problems,the key technology to solve the problem is found,which lays the foundation for the successful completion of the bridge.