Quick thinking and a unique construction solution allowed crews to repair a burned wooden trestle on the southern approach of the 72-year-old Pattullo Bridge in Vancouver, British Columbia, in eight days rather than the anticipated six weeks.
The compression-arch, suspended-deck bridge caught fire Jan. 18. As firefighters battled the blaze, Mark Smith, vice president for Surespan Construction, North Vancouver, B.C., hustled his family into his truck and drove to the site. After surveying the charred timbers, Smith called Buckland and Taylor Ltd., the local bridge design firm hired to design a replacement for the wooden structure, to devise a solution.
The answer: a prefabricated steel and concrete composite structure used during the construction of the Canada Line rapid transit project would be used again to plug the 65-ft gap in the 4,000-ft bridge. “We have a lot of these prefabricated structures in our inventory, but you don’t always have the prefect solution for the crisis,” says Smith. “But after talking to my project manager about our inventory of bridges, I knew we had a really good solution that would probably work.”
“We took a look at it with TransLink and Surespan, and we determined it was a good fit,” concurs Darryl Matson, vice president of Buckland & Taylor.
The disassembled section lay in the company’s Langley equipment yard. The girders were ready to be bolted together again and reinforced-concrete deck sections could be placed on top. The structure was originally used as a temporary bridge to allow workers to cross excavated gaps during Canada Line construction on Cambie St in Vancouver. It was shortened 10 ft to fit the Pattullo Bridge’s damaged area.
Two days after the fire closed the bridge, TransLink reached a turnkey contract with Surespan on the supply of all materials, fabrication and construction for the $2-million repair project. Surespan quickly mobilized its crews and equipment to work 20 hours a day until the bridge reopened in time for the Jan. 25 morning commute.
Two massive cranes were relocated from a bridge project in Prince George, B.C. Dozens of workers flew in from Prince George, the Yukon and Saskatchewan. Four days after the fire, they began driving 12 steel pipes 130 ft deep below the bridge, to be filled with concrete for pilings to support the new section. “Fortunately, Buckland and Taylor had already done a great deal of work in advance, and we understood the soil conditions and other requirements and constraints of the site, so we could evaluate this new wrinkle very quickly,” says TransLink spokesman Ken Hardie. “We were able to get the necessary materials and crews quickly in place and lucked out with some good weather.” To expedite construction, the City of Surrey exempted the project from a noise ordinance.
A key link between Surrey and the rest of the Metro Vancouver area, the Pattullo Bridge serves about 80,000 commuters daily. TransLink intended to replace the wooden trestle this summer while planning a new six-lane toll bridge. Preliminary work to decide the location of the new bridge, determine necessary road network improvements and assess the option of including a new rail crossing on the structure are already under way.