Nabang Hydropower Station
Hard rock - fast tunnelling
Nabang is in Yunnan province not far from the Burmese border. This is where a diversion canal HEP plant was constructed comprising master control unit, diversion tunnel and the actual power station. The plan was for a 4.5-meter-diameter diversion tunnel 9.75 kilometers long. Following commissioning, the power plant is to be run with an installed capacity of 180,000kW.
The geology meant parts of the tunnel were to be excavated by machine (7.4 kilometers) and the others were to be excavated conventionally. A part of the tunnel had to be driven under considerable overburdens of up to 600 meters. The tunnel crew celebrated breakthrough on September 10, 2011 after having driven monthly best performances of up to 475,5 meters into the rock.
