勐戛河电站导流施工方案优化

Optimization of Diversion Scheme of Menggahe Hydropower Station

云南省盈江县勐戛河电站原设计方案为分期导流,即一期通过在河床中间填筑纵向围堰,形成一期基坑,在"一枯"期间完成冲砂闸以右坝段石方开挖及混凝土浇筑;"二枯"期间填筑横向围堰利用冲砂底孔导流形成二期基坑,"二枯"完成冲砂闸以左坝段剩余石方开挖及混凝土浇筑。实际施工过程中对其进行了优化,提出明渠导流方案,即在一个枯水期完成明渠及施工导截流,从而缩短了施工工期,降低了工程成本,取得较好的效果。

According to the original design of Menggahe Hydropower Station, diversion for construction is carried out in two stages. In the first phase, the longitudinal cofferdam in the riverbed is built to form the fist pit for construction, and during the first low flow season, exaction and concrete grouting shall be completed for the dam section on the right side ofthe scouring sluice. Duringthe second low flow season, the transverse cofferdam shall be constructed and by using the scouring discharge bottom outlet the second construction pit shall be formed, exaction and concrete grouting shall be completed for the dam section on the left side of the scouring sluice. This design is optimized in the actual construction with recommendation of the open channel diversion scheme, by which the diversion can be accomplished within only one low flow season so that the total construction period will be shortened and the project cost reduced.