Special TBM needed for Himalayan drive
Mar 2010
SELI news releases
-
The Kishanganga River is to be tapped
- Squeezing conditions and difficult fault zones lay ahead of a new attempt to drive a TBM through the folded and tortured geology of the Himalaya formations in India. Subcontractor SELI of Italy is building a 6.13m diameter double-shield TBM of upgraded capacity to excavate a 14.5km long section of the headrace tunnel for the Kishanganga hydro project and install a heavily reinforced precast concrete segmental lining. The project lies high in the Baramulla District of Jammu & Kashmir and the tunnel runs under 750-1,000m of disturbed mountainous cover.
- The TBM is being designed with:
• A very high shield conicity to face the convergence phenomena
• A monster capacity for overboring and overcutting
• 2,520kW of installed cutterhead power to cope with unstable conditions in the tunnel face and
• 43500kN of auxiliary thrust to advance the rear shield in squeezing ground
-
Project plan
- The geology along the tunnel is made up, mainly, of different schist formations in which poor and squeezing rock and frequent fault zones will test the performance of the TBM and the mettle of the tunnelling crews. Extensive consolidation grouting is foreseen in the worse geological sections. The annulus behind the 5.2m i.d. lining will be will be injected in a first phase with pea gravel and in a second phase with cement grout.
-
PROJECT DETAILS
Location Village Kralpore near Bandipore in Baramulla District of Jammu & Kashmir Access Nearest rail head - Jammu 370km away Nearest airport - Srinagar 70km away Project Cost Rs. 3642.04 Crores or US$ in September 2007 prices and including interest free sub-debt of Rs. 469 Crores Beneficiary States Jammu & Kashmir, Himachal Pradesh, Punjab, Haryana, Uttar Pradesh, Uttaranchal, Rajasthan, Union Territory of Chandigarh & Delhi Year of Commissioning/ Completion Schedule Seven years from 2009 date of Government Sanction or by January 2016 Working for the project's main contractor HCC (Hindustan Construction Company Ltd) of India, SELI will provide a complete package of tunnelling equipment to the project. With the TBM this includes the backup system, the muck haulage and supply line rolling stock, segment moulds for the lining, and the ventilation system. The company will also provide a new system to pump the back-fill grout mix from the tunnel portal all the way along the 14.5km tunnel and an air chiller system on the backup to improve working conditions at the face.
-
Northern Kashmir location
- As one of few companies in the world able to build TBMs and perform the tunnelling works, SELI will second to the Kishanganga project a complete crew of TBM specialists. Excavation is expected to begin in October and finish in January 2014.
- HCC is general contractor for the entire project US$560 million turnkey-contract and awarded SELI a subcontract to complete the 14.5km TBM section of the 22.5km long headrace and install its lining. Consultant Halcrow is a joint venture partner with HCC and is completing the detailed design of the civil works, co-ordinate with the electrical and mechanical designer/contractor, and provide site support. The project's client is India's state-owned National Hydroelectric Power Corporation Ltd (NHPC).
- Located on the River Kishanganga, a tributary of the Jhelum River in northern Kashmir, the project is being developed as part of the Indian Government's 'Power for All' initiative under which some 50,000 MW of hydropower development is envisaged in the coming years. Kishanganga is one of the most important hydro projects in the country today and will also transfer water to Bandipur in the valley of Kashmir.
-
Site of the diversion tunnel works
- Using a maximum gross head of 665m, the three 110 MW Pelton turbines in the underground powerhouse will generate 1,350 million units of energy in a 90% dependable year. As well as the 14.5km long TBM drive, the 22.5km long headrace includes 8km of 5.4m diameter drill+blast excavation and the project calls for a 9.5m diameter diversion tunnel for construction of a 37m high, run-of-the-river concrete-faced rockfill dam, a 4m diameter x 998m long inclined steel-lined pressure shaft trifurcating into three 2.1m diameter penstocks to the three Pelton turbines, a 15m diameter x 150m high surge shaft and a 900m long tailrace tunnel.
- SELI set for tough drive on Kishanganga - TunnelTalk,May 2009
|
|
|
|
|
Add your comment
- Thank you for taking the time to share your thoughts and comments. You share in the wider tunnelling community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language professional.
