万家寨水利枢纽二期截流设计与施工

Design and Construction of the Second Stage of River Closure in Wanjiazhai Key Water Project

万家寨水利枢纽施工导流采用分期导流方案，截流设计流量９１７ｍ３／ｓ，采用单戗堤立堵进占。文章重点介绍了万家寨水利枢纽二期截流设计与施工。

The design and construction of the second stage of river closure are introduced in detail.The closure time,closure discharge,closure method,size of closing dyke,location of closure,materials for closure,matters concerning connstruction of closure,together with hydraulic model test are included.The closure work was completed on December 9,1995.A lot of valuable data obtained by actual measurement during the closure operating period are additionally presented in this paper: the width of the closure-gap in beginning of the closure operation is 60 m, which is equal to the design value,the discharge through the closure gap of 60 m varies from 675m 3/s to 345m 3/s; when the width of closure gap decreased to 18.6m, the dischage is 400m 3/s, the corresponding flow velocity reached up to the maximum of 6.75m/s;when the width of closure gap decreased further to 6m,the fall head along the closure gap reached up to the maximum value of 3.49m,with the discharge being 345m 3/s;the materials was tipped into the closure gap with a rate of about one dump car per minute by the method of “end tipped closure with one bank”from right to left to fill gradually the closure gap,which is located in the right side of the Yellow River,in all total,12 954 m 3 of stone ripap,1038m 3 of boulder,1044m 3 of steel wire gabion and 88 of tetrahadron blocks have been used for filling the closure-gap of 60m,4 of tetrahadron blocks and 3 of gabin set (each has 15 12 t in weight)have been removed by 10 7m from their original tipped positon after being flushed.