Cavico and Southern Hydropower Joint Stock Company signed on 6th June, 2006 a contract for the provision of construction services and supply equipment for tunnel works, power waterways, intakes, surge tank and other works for the Dasiat hydropower project. The value of the contract is approximately USD4.36 million, with the duration of work estimated to be approximately 18 months. In accordance with contract planning, work will commence on 1st July, 2006. Visit www.cavicovn.comSouthern Hydropower Joint Stock Company is the general contractor for the Dasiat hydropower project. Cavico is the only subcontractor. The project has been designed and engineered to provide a capacity of 13.5 MW. The hydropower facility is located on the main flow of Dasiat stream, which is downstream from Dong Nai 3 and Dong Nai 4 hydropower plants. The project is located in Lam Dong province, 160 km from Dalat City (250 km north of Ho Chi Minh City).The scope of work includes mostly a 2,307 m tunnel access with a diameter of 2.3 m. Geology is mainly hard rocks (granite). For this project, two drives (from the intake and valve house) will be started. The planned method of excavation is drilling and blasting, with three Furukawa leg drills and one for standby. In accordance with Vietnamese standard, all explosives have to be a local explosive (P113) produced in Vietnam. The explosive P113 is similar to Powergel P3151 produced by Orica from Australia. Mucking-out by 2.5 cu m Tamrock Toro LHD and small dumptruck. Visit www.furukawakk.co.jp/e_index.htm and www.toro.sandvik.comAt the outlet and inlet of the tunnel, steel ribs will be installed together with rockbolts supplied by AJG and shotcrete. An Aliva sprayer and Putzmeister concrete pump will be used. No support will be needed in other parts of the tunnel. Visit www.sika.ch/stm.htm and www.putzmeister.deFor mucking-out, the tunnel will be enlarged to 3 metres at chainage 0+500 to allow for dump truck movements. The enlargement will be done by drilling and blasting. The surge tank is constructed with a Robbins 61R raiseborer. Visit www.robbinstbm.com 26/06.
