滩坑水电站“先闭气后截流”导流方式的实践
摘要
The Tankeng Hydropower Station is short in construction period and big difficult in its first flood season with big risk. For this reason, the diversion way of ”air close first and then river closure” is adopted and the crest elevation of cutoff wall is lifted to above the upstream level after river close. The cutoff wall in the river close section that was planned to be constructed in 2005 after river close was completed before flood season. After rive closure, the diversion tunnel will release all inflow from upstream river. All these measures provided more than one-month construction period for the foundation excavation and upstream cofferdam filling, which greatly reduced the construction intensity of the first peak construction period, enhanced the water retarding standard during the cofferdam construction period at its low elevation, solved the high risk caused by flood season and smoothly completed the construction task before flood season.