为了检修尾水闸墩水下部分 ,延长其使用寿命 ,改变闸墩破损部位状况 ,需要一种挡水结构围堰 ,能在尾水闸墩内创造出施工环境 ,在这种情况下 ,采用大跨度浮箱式钢叠梁门围堰 ,满足了尾水闸墩的检修 ,实践证明此围堰是国内首创的一种大跨度围堰型式 ,可以在水电厂水下检修中推广应用 In order to overhaul the underwater part of the tailrace pier and extend its service life and change the damaged part of the pier, a kind of cofferdam of the water retaining structure is needed to create a construction environment within the tailrace pier. In this case, a large-span Floating box steel beam cofferdam cofferdam to meet the repair pier tail pier practice has proved that this cofferdam is the first of a large span cofferdam type can be used in hydropower overhaul in the maintenance