Specialist examines garage collapse

A forensic engineer will determine what caused a heavy concrete beam to fall at the St. Petersburg building site.

By BRYAN GILMER

© St. Petersburg Times, published May 31, 2000

ST. PETERSBURG -- The city brought in a forensic engineer Tuesday to investigate how a 45,000-pound concrete slab came crashing down from its place in a parking garage being built downtown.

The accident caused small portions of three levels to collapse Friday. There were no injuries.

The forensic engineer, Simon Harton of Tampa-based Leap Associates International Inc., is an expert in pre-cast concrete structures such as the garage. Tuesday, he requested design specifications, construction drawings and other documents and looked over the accident site.

"Their preliminary review gave no doubt to the reason of failure described by Dura-Stress," the contractor pouring the concrete pieces and assembling them on the site, City Engineer Mike Connors said.

Dura-Stress Inc. officials say a worker mistakenly removed temporary welds from a T-shaped floor beam, allowing it to topple from the small ledges, called haunches, that each end rested on. The fourth-floor beam crashed through the third floor and into the second floor, damaging at least seven beams.

The company cast all the concrete pieces of the garage at its Leesburg headquarters and trucked them here for assembly on the site like the pieces of an Erector set.

Human error as an explanation for the accident would not call into question the design or strength of the $12-million structure or likely delay the completion of the garage in time for the November opening of the nearby BayWalk entertainment development.

Connors said the haunches looked fine Tuesday, indicating that they did not break but that the beam toppled off as Dura-Stress says.

However, no one released the name of the Dura-Stress welder the company says is responsible for removing the welds. They also would not say whether the accident had affected his employment.

"I don't have that," said Dura-Stress marketing director Glen Switzer. He declined to call someone else to get the information.

"He was at the job today," Connors said. "Beyond that, I have no idea what they might do with this gentleman."

The federal Occupational Safety and Health Administration was conducting its own investigation Tuesday to determine whether any federal regulations were violated, area director Lawrence Falck said.

Harton, the forensic engineer, said he will verify the structural integrity of the rest of the structure and decide conclusively what caused the beam to fall.

Dura-Stress then must come up with a safe way to take apart enough of the structure to remove and replace the beams damaged in the fall without disturbing the rest of the garage. That process is likely to be complicated.

"They've identified the pieces that were damaged, and we've instructed production to start recasting those," Switzer said. "I would expect by early (today), they would have a plan of attack."

Work remains stopped at the site for now, but Connors said it likely will resume soon.

"Everyone feels there is a strong possibility we can let the contractor proceed with doing work on other parts of the site while the area that failed is being repaired," he said.

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