小边跨钢——混凝土混合梁桥设计

Design of a Small Side Span Steel-Concrete Composite Bridges

常规变截面预应力钢筋混凝土连续梁桥边中跨比约为O.6,钢一混凝土混合梁桥边中跨比一般大于0.4,南京机场二通道跨秦淮新河桥受条件所限,跨径布置为35 m+130 m+35 m,边中跨比仅0.23。本项目创造性地采用了关于中支点不对称的混凝土主梁结构设计,并于边支点处通过加大横梁及结构断面尺寸实现压重,满足了结构所需的各项指标要求;采用部分截面连接承压传剪式钢混结合段,传力均匀、直接。

The ratio of side span to main span of conventional prestressed concrete continuous girder bridges with variable cross-section is about0. 6, but the ratio of the steel and concrete composite bridges is generally greater than 0. 4. The bridge across the New Qinhuai River of Nanjing Airport Second Channel is limited by the conditions, the span arrangement is(35+ 130 + 35) meters, and the ratio of side to main span is only0.23. This project adopts the main beams with middle fulcrum asymmetry, besides, the pressure is realized by increasing the size of the cross beam and the structural section at the side fulcrum to satisfy all the requirements of the structure. In addition, the project uses partial cross section connecting the steel-concrete composite segment with compression-shear transmission to make the force transferring uniform and direct.