围堰是水利工程基坑施工的重要屏障,根据围堰运用条件的不同,可以分为全年挡水围堰及桔水时段挡水,汛期淹没基坑的过水围堰两大类。全年挡水围堰一般为充分利用当地材料的土石围堰。而过水围堰则根据过水时堰面流速的大小,结合当地条件,做成木笼填石加混凝土面板型、土石与混凝土面板 Cofferdam is an important barrier to the construction of foundation pit of water conservancy project. According to the different conditions of cofferdam, it can be divided into two categories: water retaining cofferdam in whole year, water blocking in orange water period and water cofferdam inundating foundation pit in flood season. The annual water cofferdam is generally made of local materials to make full use of rock cofferdam. The water cofferdam is based on the size of the flow through the weir when the water flow, combined with local conditions, made of cages stone and concrete panel type, soil and concrete panels