Xe-Pian Xe-Nammoy Project TBM en route15 December 2014
LAOS - A double shield TBM in on its way to the Xe-Pian Xe-Nammoy Hydropower project. The project calls for the construction of two central cored rock fill dams, waterway tunnels with a vertical shaft and a powerhouse generating capacity at 410MW.
The main contractor for the work is SK Engineering & Construction of Korea, who subcontracted the tunnelling work to Seli Overseas of Italy. This is an 11.5km low-pressure headrace tunnel.
The 5.74m-diameter machine successfully completed factory testing on 6 December. A spokesman for TBM manufacturer Terratec said, "The TBM will bore through mudstone, siltstone and sandstone and for that propose, the cutterhead was designed to be robust and versatile, mounting heavy duty 17'' disc cutters and keeping four large bucket openings. The 2,000kW Electric VFD Main Drive will allow the cutterhead to cut efficiently the hardest rock zones at the maximum speed of 7rpm and also to deliver an exceptional torque of 8,000kNm to cope with those fractured parts of the alignment.
"Other features on the TBM include high-speed re-gripping system, a single shield advance mode, and a high-pressure emergency thrust among others."
The project is located in the south of Laos on the Bolaven Plateau, around 80km east of Pakse and 35km northwest of Attapeu.