Nam Ngum 2 Hydroelectric Power Project Encountered Technical and Economical Challenges
The 182 m high CFRD is under construction on the Nam Ngum River one of major tributaries of the Mekong River in Lao PDR. The project site is at the rim of the Nam Ngum 1 reservoir and 35 km from the Nam Ngum 1 dam,the current largest dam in Lao since 1970s. The objective of the project is to produce electricity for sale to Thailand for the concession period of 25 years. The project cost is US $ 780 million. The construction had began since the end of 2006 and is scheduled to start impounding and commisioning in March 2010 and December 2010,respectively. The dam was designed to be different rockfill zones using filter design criterion. The rockfill sections generally require the sound rock,well graded and free draining. The upstream zones were designed to be more impervious than the downstream zones,a better material quality is required for the upstream zones whilst a poorer quality can be adopted in the downstream zones. The rockfill is mainly derived from rock mass fractured by blasting from the quarry in the vicinity area where the geological formations consist of medium bedded to massive cliff forming sandstone inter bedded with siltstone layers. According to the rock properties from a large mold triaxial test,siltstone was prohibited to mix with the downstream rockfill zone,namely 3C zone. To use only sandstone for embankment,quantity of rock excavation from the quarry have increased from 8.9 million m3 to somewhat 13 million m3. The project encountered the difficulty in quarry exploitation planning and keeping the completion target.Planning of quarry have to be in such a way that feeding of sandstone rockfill shall be done without interruption. The quarry area has been extended into 3 quarries and each of them has at least 3 faces in operation at the same time,almost double amount of machines and equipment have been also increased for the quarry development,exploitation and removal of siltstone layers. This have happened since early 2008 when the oil price and steel price hit the highest prices in the mankind history. The EPC Contractor suffered with the overrunning cost and seeking for the claims related to unforeseen geological condition and force majeure related to the hike of construction material prices.With the good collaboration of all parties and the fairness treatment,the claims were settled on the right time and the project was then able to move on.
embankment rockfill quarry
Pratoomkhuan Ngarmsirilertsgoon Sakolkiat Puangpatcharakul
Nam Ngum 2 Pozver Company Limited,215 Lanxang Rd.Ban Siang Yuen,Chantaburi,Kam-paeng Nakone,Vientiane,Lao PDR
国际会议
The 1st International Symposium on Rockfill Dams(第一届堆石坝国际研讨会)
成都
英文
83-92
2009-10-18（万方平台首次上网日期，不代表论文的发表时间）