铁路桥梁预应力管道摩阻试验方法及控制

Friction Loss Test and Control of Prestressed Tendon Ducts of Railway Bridges

我国新建铁路中大量采用了预应力混凝土简支梁和连续梁结构形式。对于预应力梁,施工过程中预应力的准确施加十分重要,直接影响到梁体的抗裂性能和后期徐变上拱的控制,施工时应严格控制预应力管道的定位和成孔工艺。介绍预应力管道摩阻的试验原理、方法和常用的管道定位方式,分析铁路32、24 m简支梁的管道摩阻测试统计结果,总结预应力施工中的常见问题并提出了相应的解决方法。结论可为预应力梁的设计和施工提供参考。

Prestressed concrete simply-supported beams and continuous beams have been used extensively in China..It is very important for the prestressed concrete beams to apply the prestressing forces exactly in construction,which will directly affect the crack resistance of beams and the control of creep deformation.The location and pore-forming process during the construction of tendon ducts should be strictly controlled.Test principles,methodology,common pipeline positioning modes and pore-forming technology are introduced in the paper.Test statistical results of friction loss are analysed for simply-supported beams of 32 m and 24 m spans respectively.Meanwhile,the common problems of the prestressed construction are summarized and the corresponding solutions are proposed.The conclusions can be taken for guidance to the design and construction of prestressed concrete bridges.