Convention center's problems outlinedEdit
During its construction, the David L. Lawrence Convention Center, designed by New York architect Rafael Vinoly, was touted as an "unconventional" building whose cable-stayed roof allows column-free exhibition halls.
But as the center rose along the banks of the Allegheny River, it was dogged with problems. Here is a look back at some of them:
Nov. 14, 2001 -- Work is temporarily halted on a portion of the project near 10th Street after the discovery that possible underground shifting or settling of the earth may have affected the stability of some of the 500 concrete-and-steel caissons that extend 70 feet down to bedrock. The caissons are part of the "nine line," the ninth in a series of 15 lines of caissons and steel support trusses, running north to south, that support the center's sloping metal roof.
Nov. 20, 2001 -- Repairs begin on the 18 underground caissons on lines nine and 10 that now seem to have been jarred out of alignment by construction equipment. Holes are drilled down through them, and the holes are filled with additional rods of reinforced steel and cement-based grouting to hold them in place.
Feb. 12, 2002 -- Ten days before the first phase of the center is to open for the first time for a recreational vehicle show, a 90-foot-tall steel truss crashes to the floor, killing ironworker Paul Corsi and injuring two others. The collapsed truss is the 13th in the series of 15 steel support trusses.
June 5, 2002 -- At a coroner's inquest into the death of Mr. Corsi, metallurgist Robert Elmendorf testifies that he thinks construction workers used the wrong type of nuts to secure the truss in place. Mr. Elmendorf of Modern Industries Co. was hired after the collapse by the general contractor, Turner-P.J. Dick-ATS.
July 22, 2002 -- At the coroner's inquest, Mr. Elmendorf raises new questions about the quality of structural materials used to build the convention center. He says his testing showed that 30 anchor bolts used in the collapsed section were not adequately strengthened. Asked if he thought the bolts used in setting other trusses in the building were substandard, Mr. Elmendorf says there is no way to get an answer because those bolts are encased in concrete.
Nevertheless, Mr. Elmendorf testifies that he believes the building is safe, as does Sports and Exhibition Authority director Stephen Leeper. "We have gone back and inspected all major connections," Mr. Leeper says. "I am by no means concerned that there are any major structural issues with that building."
July 31, 2002 -- The U.S. Occupational Safety and Health Administration levies citations and fines against two companies that fabricated and erected the steel truss that collapsed. Federal inspectors cite ADF International of Quebec and Dick Corp. of Pittsburgh for three "serious" safety violations and fines each company $19,000. ADF manufactured the giant steel trusses and hired Dick as a subcontractor to do the erection. The violations include using "improper nuts" to connect to bolts, failing to properly tighten some nuts and failing to do proper inspections on the job site.
Nov. 16, 2002 -- Dozens of cracks are reported in parts of the center's concrete floors, including several in a large exhibit hall on the second floor and many more in service corridors on the third level. The cracks vary in width from hairlines in many places to as much as a quarter-inch or three-eighths of an inch in a few spots. Some are up to half an inch deep. And some of the hairline cracks snake along the floor for several feet. They are regarded as cosmetic, not structural.
September 2003 -- ADF International files a $4 million lawsuit against the Sports and Exhibition Authority for nonpayment for additional work performed in stabilizing the caissons jarred out of alignment and for stabilizing a cable connection that caused cracks to form in a steel beam in the northeastern corner of the convention center. ADF claims it was not at fault for the hairline cracks, saying in its lawsuit that the "underlying cause ... is believed to be attributable to design errors and/or omissions by SEA's architect and/or structural engineer."
Citing other changes it was asked to make on the project, ADF claims that "the building structure and the connections as designed by SEA's architect and structural engineer are reacting to and/or experiencing higher loads, stresses, moments, pressures and/or forces that may be different than those originally anticipated by SEA when it published the contract documents for bidding."