March 5, 2007

INTRANSIT BC

Approximately 252,000 cubic metres of concrete are required for the Canada Line. The proposed Evergreen Line, an 11-kilometre light-rail project from Lougheed Town Centre in Burnaby to Douglas College in Coquitlam, will likely use far less concrete.

Rapid Transit

Pre-cast segments help streamline rapid transit project

InTransit BC opts to pre-cast segments of the elevated guideway

Peter Mitham

correspondent

Vancouver

Pre-casting is helping streamline construction of the Canada rapid transit line between Vancouver and Richmond, and promises a higher standard of workmanship than conventional cast-in-place work. Approximately 252,000 cubic metres of concrete are required for the Canada Line, which is set to open in 2009.

Given the tight deadline in a heated construction market, InTransit BC (the consortium that is managing the design, construction and operation of the transit line) opted to pre-cast segments of the line’s elevated guideway at a facility in south Vancouver at Fraser and Kent Avenue.

The guideway crosses Marine Drive at Cambie Street and heads south across the Fraser River towards the airport and Richmond, where the line runs along No. 3 Road.

Each span of the guideway consists of 12 segments, which fit into each other. Pre-casting allows production of segments prior to installation, allowing each span to come together more rapidly than if the concrete for each span was poured on demand and required to cure.

“We can actually cast the segments and then stockpile them until they’re needed,” Crombie said. “We can do a lot of that in advance, and then when the segments are needed they can be trucked to the site, and lifted into place by a large crane, and then they’re set and cinched there.”

The measure is helping keep down the cost of the $1.7 billion project. “It makes things go faster, and means we can cover more ground in a faster, more efficient way,” Crombie said.

The system provides better curing of the concrete segments, Crombie added, because the casting occurs in a sheltered facility. “In terms of quality control, being able to do all this without getting in the way of other work, it just makes it a lot more efficient,” he said.

The pre-cast yard is operated by RSL Canada, a joint-venture of Rizzani de Eccher SpA and SNC-Lavalin. It employs about 150 people. The pre-cast segments require only 50,000 cubic metres of cement, a small portion of the total being poured for the Canada Line.

The cut-and-cover portion of the line downtown and along Cambie Street requires 117,450 cubic metres of cement while tunneling and stations require a total of 84,5000 cubic metres.

The proposed Evergreen Line, an 11 kilometre light-rail project from Lougheed Town Centre in Burnaby to Douglas College in Coquitlam, would likely use far less concrete because it will run largely at grade and not require the tunneling and elevated guideways that were integral to previous rapid transit projects, said Ken Hardie, director of communications for TransLink.

Estimated to cost $59-million, the Evergreen line could be up and running by 2011.

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