February 8, 2007
A loud pop, according to bystanders, accompanied the February 5 collapse of a 20-by-60-foot concrete floor section at Rafael Viñoly’s David L. Lawrence Convention Center, in Pittsburgh. No injuries were reported.
The break in the 6-inch-thick slab opened a gaping hole in the loading dock’s floor, above an underpass where the building straddles Tenth Street. It nearly engulfed a trailer-truck and a cherry-picker that were unloading for a now-canceled auto show. Although the cause is not yet known, investigators are focusing on how rapidly falling temperatures may have affected an expansion joint. This week’s collapse is only the latest mishap in the building’s troubled history.
Designed following a 1998 competition, the center opened in phases between 2002 and 2003. Its central masts and suspended roof took inspiration from nearby bridges to create open, day-lit convention halls offering city and river views. The design earned the first LEED Gold rating for a convention center.
But its construction experienced several difficulties. Shifting caissons required unexpected repairs in November 2001, and a 90-ton truss collapsed, killing a worker, in February 2002. Cracks appeared in the concrete floors the following November, although these were later judged to be cosmetic.
Shortly after Monday’s collapse, Pittsburgh’s Sports and Exhibition Authority executive director Mary Conturo said that a team including representatives of Viñoly’s office, structural engineer Dewhurst MacFarlane & Partners, construction manager Turner/PJDick/ATS, and steel contractor ADF Group had been summoned to assess the damage and begin searching for its cause. Their early efforts are focusing on an expansion joint in the area above where caissons shifted in 2001.
Allegheny County chief executive Dan Onorato attributed the failure to “a major mistake that was made somewhere.” Joining with Pittsburgh’s mayor, Luke Ravenstahl, he insisted on an outside review.
In response, the city’s sports authority hired Wiss Janney Elstner Associates, of Cleveland, to help in the investigation. The New York firm Leslie E. Robertson Associates will also be reviewing the work of the Convention Center’s designers and construction team. The building will be closed for at least a week pending their findings and recommendations.
This is the second major Viñoly building to experience difficulties in the last few years. After Philadelphia’s Kimmel Center for the Performing Arts opened late and over budget in 2001, that city sued alleging negligence. The architect reached an out of court settlement last winter; neither it nor the city admitted liability or fault.
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