大跨径变截面双悬臂简支梁桥拆除研究及应用

Study and Application of Demolishing Long-span Variable Cross-section Double Cantilever Simple-supported Beam Bridge

以兰州市七里河黄河大桥拆除为背景,介绍了在黄河汛期,由于工期紧、施工环境狭小、安全环保要求高等因素影响,对大跨径变截面双悬臂简支梁的拆除应用,对几种可行方案进行对比,采用了架桥机拆除法,即双导梁架桥机搭设临时辅助支架并对梁体水平分层、横向分段切割吊装拆除的施工方法,应用该方法后使拆梁速度提前三分之一,总体工期提前一个月竣工通车,对今后双悬臂简支梁桥的拆除提供了很好的借鉴资料。

Taking the demolition of Lanzhou Qilihe Yellow River Bridge as its background, the paper introduces the application of demolishing the long-span variable cross-section double cantilever simple-supported beams due to the factors of the limited construction period, narrow construction site, high standards of safety and environmental protection during the flood season of Yellow River. By comparing several feasible schemes, the bridge erection machine demolishing method is used, that is, the construction method of using double–guiding-beam erectors to fix and tighten the temporary auxiliary stands and cutting, hoisting and demolishing the beam horizontally and longitudinally. This method can shorten the time by 2/3 to demolishing beam, and the project is completed one month ahead of the time, which can be referred for demolishing the double cantilever supported beam bridge in the future.