高速铁路跨度40m简支箱梁全预应力体系与部分预应力体系对比分析

Comparison Analysis on Full-prestressed and Part-prestressed Systems of 40m Span Simply Supported Box Girder on High Speed Railway

通过高速铁路跨度40m箱梁全预应力体系、部分预应力A类体系、部分预应力B类体系的设计和对比,分析了各类预应力体系40m梁的受力性能、残余徐变上拱值及材料用量。结果表明:部分预应力体系的设计主要由运梁荷载工况控制;部分预应力A类体系仅在二期恒载等级大于120kN/m时才能降低残余徐变上拱值,部分预应力B类体系可有效降低各级二期恒载下残余徐变上拱值;与采用全预应力体系相比,部分预应力体系40m简支箱梁的普通钢筋用量和混凝土用量有所增加。

The design and comparison works of the full-prestressed system,part-prestressed class A system and partprestressed class B system of the box girder with a span of 40m on high speed railway were carried out. The mechanical properties,residual creep camber and material consumption of 40m girders with various prestressed systems were analyzed.The results show that the design of part-prestressed system is mainly controlled by the load condition of transporting girder,and the part-prestressed class A system can only reduce the residual creep camber value when the secondary dead load level is above 120kN/m,how ever the part-prestressed class B system can effectively reduce the residual creep camber value at all secondary dead load levels. Compared with the full-prestressed system,the amount of ordinary reinforcement and concrete used in the 40m girder of part-prestressed system has increased.