The application of concrete cut-off wall in hydropower andwater resources industry has been started since the end of 1950s inChina, which has a history of more than 40 years. During itsapplication, three industrial specifications has been stipulated byhydropower and water conservancy industry and issued respectivelyin 1963, 1979 and 1996. These three specifications immediatelyconcluded the achievements made during the development ofconcrete cut-off wall technique, and had played an important role inguiding the construction of concrete cut-off wall in our nation'shydropower development, promoting the application of newtechnique, new material and new technologies, and guaranteeing thequality of project.

A tremendous progress has been made in recent years in ournation's cut-off wall technique. Many new experiences had beenaccumulated, especially in our nation's key project such as ThreeGorges Project, Xiaolangdi Project, etc.. This Standard is compliedby summarizing the new technique in our nation's cut-off wallconstruction practice and also combining the experiences fromoverseas projects.

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