关键词: 下闸封堵, 方案优选, 临时堵头, 永久堵头, 长河坝水电站

Abstract: The water head for retaining the normal water level of Changheba Hydropower Station diversion tunnel plug is up to 212.00 m, the plugging work is large and the procedures are complex, which directly affects the power generation schedule. According to the characteristics of diversion tunnel closure construction, through the calculation and analysis of structural stability, four schemes including water-retaining with permanent plug, water-retaining with lock gate, combination of permanent plug and temporary plug, downstream placement of No.2 diversion tunnel plug position were proposed, and then comprehensive economic and technical comparison were made from the perspective of power generation schedule, construction progress, construction safety, project investment and so on. Finally the optimal scheme was selected. The study results can provide reference for the design and optimization of gate closing and plugging of similar high rock fill dam.

Key words: gate closing and plugging, scheme optimal selection, temporary plug, permanent plug, Changheba Hydropower Station