June 11, 2009

Wood may be the prominent feature in the finished Richmond Speed Skating Oval but steel gives it the underlying strength. It has 15 glulam pine and steel arches.

Wood and steel design is a unique marriage at Vancouver’s 2010 Winter Olympics

60 massive V-arched trusses, 15 roof arches of glulam and steel are secured with 250,000 screws

PETER KENTER

correspondent

Wood is the most prominent feature of the 2010 Olympic Winter Games speed skating oval but steel trusses provide its structural strength.

The Olympic oval is part of the City of Richmond’s $178-million arena on the shores of the Fraser River. George Third and Sons (GTS) of Port Coquitlam handled the $12-million contract to supply and install the structural steel, most of it used on the building’s 15 steel-and-glulam roof arches.

The innovative design called for the contractor to create 60 massive V-shaped arched trusses married to glulam pine. Each of the 18-tonne truss sections measured approximately 26 metres long and required 250,000 screws to assemble.

GTS began the project in October 2006. The trusses were manufactured by Dynamic Structures of Port Coquitlam, a company owned by GTS, while the laminated wood portion of the trusses were fabricated by Structurlam Products of Penticton.

“We were definitely faced with a very demanding schedule, and there were many challenges marrying wood to steel,” says Ziggy Welsch, Project Manager for GTS. “The steel is obviously stronger and more forgiving than the brittle wood, so more thought had to go into fit-up procedures and handling. We had to protect the wood wherever we were welding to prevent damage to the wood glulam beams. The assembly took up a lot of our shop space and the extremely complicated geometry to fabricate the two glulam beams into a V-truss to form the radius was the biggest challenge.”

The innovative design called for the contractor to create 60 massive V-shaped arched trusses married to glulam pine. Each of the 18-tonne truss sections measured approximately 26 metres long and required 250,000 screws to assemble.

Each of the 60 completed truss sections were shipped to site one at a time on a trombone trailer.

On site they were covered to help protect them from moisture, as well as UV rays, which could damage painted areas and fade the wood glulam.

A 200-ton crane was used to lift the truss sections into place. “First the two end pieces were lifted into position supported by heavy-duty steel towers bearing the ends of the trusses,” says Welsch. “Next, the two middle sections were assembled and spliced together on the concrete slab and lifted into place as one to fill the void in the middle. Jacking against the concrete buttress, the field crew pushed the trusses together until our final required positioning was achieved and then the ends were filled with a high-strength grout to complete the span of approximately 100 metres.”

The fabricating company also manufactured a series of curved steel beams that decorate the exterior edge of the roof. Johnston Architects Inc., principal and lead project architect, designed the beams to reflect the blue heron, a bird that nests in the area.

Once on site, the truss section pieces were covered to help protect them from moisture, as well as UV rays, which could damage painted areas and fade the wood glulam. A 200-ton crane was used to lift the truss sections into place.

“The complicated twisted wide flange beams at the north end of the building are highly visible and simulate a heron feather,” says Welsch. “These were not only challenging to fabricate in our shop, but also to erect. With the help of our seasoned field crew we managed to push, pull and pry the steel into position.

The Olympic Oval has already won a prestigious Award of Excellence in For Architectural Innovation from the Royal Architectural Institute of Canada.

The jury praised the structure for its innovative use of pine beetle-killed wood spanning the “elegant” roof and the seamless integration of the mechanical systems, as well as the building’s transparency, which maximizes daylight.

In addition to the use of one million board feet of pine-beetle wood in the ceiling, which the jury called “stunningly beautiful, they were also impressed with the Oval’s innovative used of glulam beams spanning almost 100 metres, to creatively integrate with the ceiling.

As such and ironically, most of the structural steel employed in the creation of the skating oval will be invisible to the thousands of Olympic fans filling the stadium in 2010.

“I must say by now we’re used to being covered up,” says Welsch. “The important thing is we know that without our steel these trusses could not have been possible. It’s a combined effort and all of us involved with this once-in-a-lifetime project feel very proud to have contributed to its success.”

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