大跨活性粉末混凝土混合梁斜拉桥的方案设计及性能分析

Schematic Design and Performance of Long-span Cable-stayed Bridge with Hybrid Girders of RPC and Normal Concrete

为探讨活性粉末混凝土RPC在混合梁斜拉桥中应用的可行性,以一座主跨260m钢+C55普通混凝土混合主梁的独塔双索面混合梁斜拉桥设计方案为基础,考虑结构整体和局部受力及稳定性等要求,将原桥钢主梁替换成RPC120主梁,构造了一座类似布置形式的RPC120+C55混合主梁斜拉桥方案,并对两种方案的结构静、动力性能和稳定性能及经济性能进行了分析和比较。结果表明:从结构受力性能角度而言,采用RPC+C55混合主梁所构成的混合梁斜拉桥结构体系具有良好的结构受力性能,加之同为水泥基材料的普通混凝土与RPC之间良好的相容性,使得梁内无需设置构造复杂的结合段。所提结构体系在结构受力、构造及经济指标上均具备实际应用的可行性。

To investigate the applicability of reactive powder concrete (RPC) in cable-stayed bridge with hybrid girders,based on a cable-stayed bridge of 260 m long main span with a hybrid girder by steel and C55 normal concrete,a new cable-stayed bridge system of the same span layout with RPC120 substituting for steel in the girder,was designed considering the structural stiffness,stress and stability.The comparative study on the static,dynamic and stability properties as well as the economic performance of these two bridges were carried out.The results show that the new cable-stayed bridge structure has an expected mechanical performance,additionally,the better compatibility between the ordinary concrete and RPC both of cementitious materials results in that the complicated joint as in the steel-concrete hybrid girder could be avoided,which makes the new structure be of feasibility in practice due to its excellent loading performance and simpler construction requirements.