蒙西华中铁路公安长江大桥4#主塔墩基础施工

Construction of the No.4 Pier's Foundation of the Yangtze River Bridge in Gong'an Section of the Railway from Western Inner Mongolia to Central China

蒙西至华中铁路在湖北公安县跨越长江,公安长江大桥4#墩是主跨南主塔墩,该墩基础采用先围堰后平台法施工,钢套箱在大坡度场地上拼装制造,采用气囊顶升滑移下水、浮运就位,围堰、钢护筒和内支架共同受力作为钻孔施工平台,钻孔桩完成后,接高围堰,在吊挂系统配合下下放围堰至设计标高,清基后水下分区封底,抽水进行承台施工等施工方案。

The railway from Western Inner Mongolia to Central China crosses the Yangtze River in Gong＇An country of Hubei province, and the No. 4 Pier of its bridge is a main pier of the southern side. For the construction of the pier＇s foundation, a cofferdam is built at first and then the platform. The steel box is assembled in a site on a large slope. The method of Gasbags lifting and sliding into water is applied with the method of floating into position. The cofferdam, the steel support and the inner support are combined together to form the drilling platform. After the bored pile is completed, the cofferdam is built higher to meet the design by lowering the cofferdam into position in coordination with the suspension system. After the foundation is cleaned, the bottom is sealed section by section underwater. The cushion cap is constructed after water pumping.