三峡库区大型钢吊箱围堰设计与施工研究

Design and Construction of Large Steel Suspension Box Cofferdam in the Three Gorges Reservoir Area

重庆市奉节县某大桥位于三峡库区的深水区,施工期大桥7#桥塔处最大水深约47m,水位变幅高达30m,桥塔位置地质条件复杂。为解决承台及桥塔施工的难题,大桥7#桥塔采用双壁钢吊箱围堰,按先成桩后围堰的顺序进行施工。钢吊箱围堰外轮廓尺寸为50.7m(长)×31.5m(宽)×43.0m(高),壁厚2.0m,竖向共分7节。围堰设计过程中,考虑了制造、运输和安装的不同工况,计算结果显示围堰构件不同工况下均安全可靠,满足施工要求。

A certain bridge in Fengjie County,Chongqing is located in the deep water area of the Three Gorges Reservoir Area.During the construction period,the maximum water depth at the 7#tower of Bridge is about 47m,with a water level fluctuation of up to 30m.The geological conditions of the 7#bridge tower location are complex.To solve the difficulties in the construction of the bearing platform and bridge tower,the 7#bridge tower adopts a double wall steel suspension box cofferdam,which is constructed in the order of pile formation first and then cofferdam.The outer contour size of the steel suspension box cofferdam is 50.7m(length)×31.5m(width)×43.0m high,with a wall thickness of 2.0m,vertically divided into 7 sections.During the design process of the cofferdam,different working conditions of manufacturing,transportation,and installation were considered.The calculation results showed that the cofferdam components were safe and reliable under different working conditions,meeting the construction requirements.