THE STUDY ON THE KEY TECHNOLOGY ISSUES OFCONSTRUCTION DIVERSION DESIGN FOR THE HIGH ARCH DAMOF GOUPI-TAN HYDROPOWER STATION ON WUJIANG RIVER

摘要

Goupi-Tan Hydropower Station is located on Wujiang River in Yuqing County, GuizhournProvince. It is one of the series of hydropower stations in the middle reach of Wujiang River. The station isrnmade up of double-curvature arched dam, flood releasing structure, right bank underground powerhouse,rnleft bank third class vertical ship lift and vertical seepage proof curtain. The maximum height of dam isrn232.5m, and the installation capacity of generating station is 3000MW. Based on the characteristics of thernproject, the technology difficult problems were come up against during the construction diversion design. Itrnincludes diversion standard selection with adjusted flood flow by the upstream reservoir, the diversionrntunnel construction with large section in the soft rock area, high speed building RCC cofferdams, settingrnoutlet hole in the dam for later diversion stage, etc. The all-year diversion mode of RCC cofferdam blockrnwater and diversion tunnel release the flow is adopted for the initial stage. And the all-year diversion modernfor mid and later stage is the dam block water temporarily, release flow through bottom outlet, emptyingrnoutlet, sluice deep outlet, crest outlet and flood discharging tunnel. The Goupi-Tan Hydropower Stationrnbegan closure the river in November, 2004. The upper and lower RCC cofferdams were constructed fromrnFebruary to June in 2005.The water seepage of foundation ditch is little during cofferdam block water inrnflood season in 2005 and 2006.