水流湍急深水区跨江大桥基坑支护施工技术

Foundation pit support technology of river crossing bridge in deep water area with turbulent water flow

拉林铁路洞嘎雅鲁藏布江大桥承台底水深16.8 m,而且河水湍急,常年过水,增加了基坑施工的难度和施工安全风险。为分析跨江大桥水流湍急深水区基坑支护技术,结合洞嘎雅鲁藏布江大桥的实际情况,通过方案对比分析,选择以筑岛围堰+钢筋砼围护桩+旋喷桩止水帷幕作为本次深水基坑施工的方案,为基坑施工营造一个良好的条件,实现和桩基同步施工,既能保证施工质量,又不会耽误工期,满足洞嘎雅鲁藏布江大桥深水基坑施工的实际要求。

The water depth at the bottom of the pile cap of Dongga Yarlung Zangbo River Bridge on Lalin Railway is 16.8 m, and the river is fast flowing, which greatly increases the difficulty of foundation pit construction and construction safety risks. In order to analyze the foundation pit support technology of the river crossing bridge in the deep water area with rapid water flow, combined with the actual situation of the Dongga Yarlung Zangbo River Bridge, through the comparison and analysis of the schemes, the island cofferdam+reinforced concrete retaining pile+jet grouting pile water stop curtain is selected as the scheme for the construction of the deep water foundation pit, creating a good condition for the foundation pit construction, realizing the synchronous construction with the pile foundation, which can ensure the construction quality and will not delay the construction period, and meet the actual requirements of the deep foundation pit construction of Dongga Yarlung Zangbo River Bridge.