N a watertight structure, usually of sheet piling, that encloses an area under water, pumped dry to enable construction work to be carried out. Below a certain depth a caisson is required 围堰; 一种防水建筑物，通常由钢板桩筑成防水层，将水下某一区域围住，并将结构内水排干以便可以施工，在水下一定深度时，需要佩戴潜水箱
Cofferdams are made by driving metal sheet piling into the Bed to form a watertight fence.
在近代工程中，筑围堰时一般先打下钢板桩以形成阻水层。
When the cofferdams are completed and made safe, the water trapped between them is pumped out.
围堰完工稳固后，就将围堰间的水抽干。
The workers have to race against time and weather to shore up the cofferdams and make them secure.
工人得和时间和天气赛跑，强化围堰使之牢固。
应用推荐