Robbins TBM Advances Lebanon's Water TunnelThe Kesrouan coastal area water supply project (KCAWSP) in Lebanon is funded by the Ministry of hydraulic and electric resources, the Council for development and reconstruction and the Kesrouan water authority. The project along Lebanon's coast will ultimately bring fresh water to a parched and heavily populated region. The entire project aims to enhance the country's water network with a system of catchment works, pumping stations and distribution tunnels that will serve 252,000 customers by 2020. Once complete, the project will supply up to 89,000 cubic metres of clean water per day, sourced from the river Nahr Ibrahim. It involves nine pumping stations, 29 reservoirs, 51 km of transmission pipelines, as well as the 4,030 m El Madiq water conveyance tunnel, with a 3.8 m excavated and finished diameter. As part of contract 2054 of this water scheme, the El Madiq tunnel is being built under Mount Lebanon in Casa of Kesrouan in the valley of Nahr Ibrahim, 40 km north of Beirut. Tunnelling has been contracted by the Council for the development and reconstruction to the Baresel / Al Tajj Est joint venture. The DAHNT-MWH joint venture formed by Dar Al Handasah Nazih Taleb & Partners of Lebanon and Montgomery Watson Harza of the UK is responsible for work supervision. Visit www.daralhandasah.com and www.mwhglobal.comIn August 2006, work on the project was halted due to conflicts in the region. Lebanon's infrastructure sustained more than USD2.5 billion in damages during the July 2006 war with Israel. Most of Lebanon's construction projects were stopped or abandoned altogether. When the war started, the TBM had not been launched yet. Crews left the worksite immediately. No damage was sustained to either the TBM or equipment from the conflict but the project was delayed about four and a half months. Crews returned to the project site to resume TBM assembly and begin boring operations in December 2006. The geology is composed of sedimentary limestone and dolomitic limestone near horizontal beds with twelve known strike-slip faults dipping 70 to 80 degrees. There are also two known karst features filled with a collapse boulder and clay matrix. The excavation through two of the karst collapse breccia zones containing a limestone boulder and clay matrix has slowed progress for approximately seven weeks.A Robbins main beam gripper, partially shielded TBM model 116-189, originally manufactured in 1979, featuring an enlarged cutterhead from 3,500 mm to 3,800 mm in diameter, is currently boring the bedrock with some areas of clay ranging from 20 to 60 MPa UCS. The TBM, using a combination of 35.5 cm face and gage cutters with 30.5 cm centre cutters is boring at a -0.35% grade. The tunnel is bored from a single heading by two 10-hour production and one 4-hour maintenance shifts, five and a half days per week. There are no other underground excavations except for the two portals for the tunnel. Visit www.therobbinscompany.com If required, the initial and final ground support can be one or combination of the six following elements: friction anchors, 34 to 38 mm hole diameter by 150 to 200 cm long; cement grouted thread bar rockbolts/dowels, 20 mm bar diameter by 150 to 300 cm long; 100 x 100 x 6 welded wire fabric; UPN 100 channel steel arch beams; HEA 100 arch steel beams; and dry-mix shotcrete without fibres.For muck haulage, two 14-tonne 750 mm gauge Ageve DHL 60 M14 mining locomotives were used initially. They have been replaced by two 135 kW 24-tonne 750 mm gauge GIA Industri DHD 25 locos that pull 16 Lewa muck cars with capacity for five cubic metres, four 5.5 m-long 2-tonne Mühlhäuser flat cars, two 3.5-tonne 12-man capacity Mühlhäuser man cars, one 2.5-tonne shotcrete car with conveyor belt to an Aliva 252 shotcrete machine and two 5-tonne Mühlhäuser batch cars. Visit www.gia.se, www.tunnelling-equipment.com and www.sika.ch/en/stm/stm-produkte-4.htmOther equipment at the site include a 1 cu m 7.5 bar CompAir compressor, two 900 mm-diameter Korfmann ventilation fans, Schauenburg Flexadux ductings for tunnelling ventilation, four 500 kVA Stanford generators with Cummings diesel engine and a Waigel transformer (400/6,000 Volt step-up). Visit www.korfmann.com and www.tunnel-ventilation.de or www.flexadux.co.ukPortal work started on 12th July, 2006. As of 22nd January, 2008, crews had driven 1,740 metres with 2,290 metres remaining. Progress today is 2,222 metres completed and 1,778 metres remaining. The USD17 million El Madiq tunnel is expected to be complete in 2008. The expected date of TBM breakthrough is 1st July, 2008. 13/08.