Capilano-Seymour Water Project in Progress in VancouverWater from the Capilano reservoir will be pumped through a 3.8 m-diameter tunnel to the filtration plant in the Lower Seymour Conservation Reserve. From here, the water will be filtered and disinfected, and returned to Capilano by gravity through a parallel tunnel of the same size. The twin tunnels will be approximately 7.2 kilometres long and 160-640 metres underground. Twin tunnelsThe tunnels are driven by two 3.8 m-diameter Robbins TBMs mainly in very strong granitic rocks, i.e. coastal mountain granodiorites 140-285 MPa UCS. They intersect a number of fault zones. 25-tonne diesel locos supplied by GIA Industri are operated with five Muehlhaeuser 5.5 cu m side tip muck cars per loco. There are three locos per tunnel. One 1.5 m TBM push represents one train load and one shaft bucket. A gantry crane (Liebherr modules to Bilfinger Berger design) hoists muck buckets and materials. Man riding in shaft is made possible by an Alimak tower frame. Visit www.therobbinscompany.com, www.gia.se, www.tunnelling-equipment.com and www.alimakhek.comSupports include rock bolts, wire mesh, steel sets (I-profile) and shotcrete (without steel fibres). There is an average of 1,250 metres of steel pipe per tunnel at Capilano end and an average of 600 metres of steel pipe per tunnel at Seymour end. Tunnel steel pipe wall varies at 25-32 mm thick. All steel pipes are backfilled with cementicious grout to the excavated dimensions.45 m probe holes are drilled with 10 m overlap and 2.33% decline. Groundwater is currently 30 l/s in RWT and 18 l/s in TWT. Pre-excavation grouting is performed where required. Ground support currently varies from none required to shotcrete, with possible ring steel sets if very poor ground conditions are encountered (none yet).Bilfinger Berger Canada expects to break through in late 2007-early 2008. The TBMs do not daylight on this project, they will be demobed from the Capilano shaft area through the TBM-bored tunnels and hoisted via Seymour shaft. Work is supervised by Hatch Mott MacDonald. Click ca/25. Read E-News Weekly 43/2005, 31/2004, 23/2002, 22/2002 & 19/2002. Visit www.gvrd.bc.caAssociated underground structuresOther underground structures include the 20 m-long, 18 m-wide, 8 m-high Seymour starter cavern, and 45 m x 34 m-long starter tunnels; the Seymour tail cavern 32.5 m long, 10 m wide and 8 m high, and a 30 m-long tail tunnel; the Capilano shaft bottom cavern, sized to suit TBM demob, raise bore reamer and liner pipe; and the Capilano shafts, twin 4 m-diameter, 275 m-deep excavations constructed by raise boring entirely in granitic rocks to surface.The Seymour shaft, which serves as the main construction shaft and is 185 m deep and 11 m diameter, has been sunk partially in glacial deposits and partially in granitic bedrock. Excavation of Seymour shaft was performed by Atlas Copco ROC 3 surface drill rigs. Excavation of Seymour shaft bottom chamber was done by a Tamrock two-boom drill rig. Full-face drill and blast was followed by shotcrete, minimal lattice girder use, rock bolts and mesh. In the shafts, steel pipe wall support varies at 20-12 mm thick. Concrete slabs have been poured at the caverns, sumps and muck pit. Visit www.atlascopco.com and www.miningandconstruction.sandvik.com 24/07.