Robbins TBMs wrap up Tunneling at Seymour Capilano

On November 4, 2010, the final breakthrough for the second of two Robbins TBMs capped more than two years of hard rock tunneling in a four year period.  The two 3.8 m (12.5 ft) diameter Main Beam TBMs, for Canada’s Seymour Capilano Water Filtration Project, completed excavation more than three months ahead of the revised schedule.  The breakthroughs occurred after the restart of the machines, following an 18-month delay over a ground conditions dispute with the original contractor.

The twin 7.2 km (4.5 mi) long tunnels, for project owner Metro Vancouver, were driven in challenging granitic metavolcanic rock, with cover of up to 600 m (1,970 ft).  The project’s second contractor, the Seymour Capilano Partnership (SCP), a Joint Venture of Frontier-Kemper Constructors ULC, Aecon Constructors and JF Shea Inc., dealt with faulting and shear zones using a successful ground support program.  Rock support varies from bare rock in good ground (Class I), to rock bolts, wire mesh, and channel straps, as well as steel sets every 760 mm (30 in) in Class V poor rock.  

“We are quite pleased with the breakthrough.  The success of this project can be attributed to having an excellent crew of knowledgeable people, good pre-planning of the work and very good TBMs,” said Frontier-Kemper Project Manager, Serge Moalli. Since SCP’s re-start of the two TBMs in July and August 2009, the machines have achieved rates of up to 29 m (95 ft) per day.

The second Robbins TBM holed through at an angle into the other tunnel, where a chamber will now be built to conduct raise drilling of the 270 m (885 ft) deep Capilano shaft.  Frontier-Kemper estimates that this work, combined with final shotcrete and steel lining in the tunnels, will take about two years.  

The completion of the project will mark one of only several examples of TBM tunneling in British Columbia.   “I think we’ve proven here that you can tunnel through the hard granitic rock of British Columbia, even with all its quirks and stress releases.  We’ve shown that this is an effective alternative to drill and blast,” said Moalli.  
Each of the two finished tunnels will be used to convey either raw or treated water between the Capilano Watershed and a new filtration plant.  The Seymour-Capilano Water Filtration Project seeks to improve the quality of drinking water in Vancouver, BC, Canada. The completed filtration system will clean 1.8 billion liters (475.5 million gallons) of water a day and will lower the water turbidity (cloudiness) and micro-organism levels to meet federal standards for drinking water.

The Robbins Company
29100 Hall Street
Solon, OH 44139
USA
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www.robbinstbm.com