长河坝水电站初期导流洞下闸封堵方案优选研究

长河坝水电站初期导流洞堵头挡正常蓄水位的水头高达212.00 m,封堵工程量大、程序复杂、直接影响电站发电工期。结合导流洞封堵施工的特点,通过结构稳定计算分析,拟定永久堵头挡水、闸门挡水、临时堵头与永久堵头结合、2号导流洞堵头位置下移4种下闸封堵方案,并从发电工期、施工进度、工程结构安全、工程投资等方面进行全面的经济技术比较,进而优选出最佳方案。研究成果可为类似高堆石坝工程导流洞的下闸封堵设计提供借鉴。

Optimal selection of gate closing and plugging scheme for initial diversion tunnel of Changheba Hydropower Station

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.