大桥水库引水工程管桥设计变更分析

Analysis on Design Variation of Pipe Bridge for Water Diversion Project of Daqiao Reservoir

凉山州大桥水库引水工程泸沽镇至漫水湾首部枢纽段线路设计为采用管桥方式穿越沿线沟壑。原设计方案中的管桥上部结构为预制T梁,但因施工现场地形起伏不平、无法布置预制梁场,且因沿线沟壑纵横、切割较深,无法修建预制T梁的运输通道。介绍了根据现场实际施工环境,在对安全、经济等方面进行综合分析后将管桥的上部结构变更为贝雷钢桥的过程。

According to the design,pipeline bridge is adopted for the section from Lugu town to Manshuiwan headwork of the water diversion project of Daqiao reservoir in Liangshan Prefecture so as to cross the gullies along the diversion line.The upper structure of the pipe bridge in the original design is prefabricated T-beams.However,due to the uneven terrain of the construction site,the prefabricated beam yard can not be arranged,and due to the vertical and horizontal gully along the line and the deep cutting,the transportation channel of prefabricated T-beams can not be constructed.This paper introduces the process of changing the superstructure of the pipe bridge to bailey steel bridge after comprehensive analysis of safety and economy according to the actual construction condition at site.