Entire Boston highway system under review after more trouble spots found
Thursday, July 13, 2006
BOSTON -- Inspectors began reviewing the city's entire highway system Wednesday -- every bridge, tunnel and roadway -- after at least 60 signs of loose bolts and other potential failures were found in the same Big Dig tunnel where a motorist was crushed by falling concrete.
Gaps found near ceiling
Initial inspections by state officials revealed that some bolts had started to come out of the concrete in the eastbound connector tunnel, part of the main route to Boston's Logan Airport. Gaps also had developed between the ceiling and metal plates that help hold the massive panels in place.
There had been plans to reopen that section of tunnel Wednesday, but Massachusetts Turnpike chairman Matthew Amorello said it would remain closed indefinitely to ensure motorists' safety and to collect more evidence in a possible criminal investigation of the tunnels' designers and builders.
Amorello added that an undetermined number of similar problem areas were found in two adjacent tunnels, raising the possibility of a broader design or construction flaw.
The widespread trouble spots prompted the Turnpike Authority to order an inspection of the city's entire highway system -- even parts that are decades old and not part of the $14.6 billion Big Dig system, the nation's most expensive highway project.
Still, Amorello insisted the tunnels remain safe.
"What happened Monday was a tragedy," he said. "I'm taking every step to ensure it never happens again."
Late Monday, 12 tons of concrete ceiling panels in the tunnel collapsed, crushing a car and killing 38-year-old Milena Del Valle. Her husband barely escaped by crawling through a window.
"It was like a bomb," Angel Del Valle told the Boston Herald. "Everything was falling. It was too fast. I couldn't stop. I couldn't do anything."
Attorney General Tom Reilly said a contractor and project manager knew about problems in that section of the tunnel as early as 1999, when five bolts failed during testing.
"It was not only identified, but there was a plan to address that problem, and what we're trying to determine right now is was that plan implemented," Reilly said, declining to provide any other details.
John Christian, an engineer hired to investigate for the Turnpike Authority, said the attachment bolts used a standard design: Holes were drilled into the tunnel's concrete ceiling and bolts were then inserted, along with pressure-injected epoxy.
'Some generic flaw'
He said it was possible that inspectors would find "some generic flaw in the systems that are used for designing these panels."
The strength and quality of the concrete used in the tunnel is key to the safe hanging of the overhead panels, according to Avi Mor, of Dr. Mor & Associates, a California-based consulting firm specializing in analysis of construction defects.
He said if concrete failure were to blame for the collapse of the panel, investigators would likely find pieces of concrete still epoxied to the tie rods.
"Concrete is a live material. It goes though cycles of expansion and shrinkage. The tunnel can vibrate," Mor said. "All these things could cause cracks if the concrete is marginal to start with. This micro-cracking can bring it to the point where it could fail."
Federal prosecutor Michael Sullivan said federal investigators were checking whether companies that worked in the area of the tunnel collapse fulfilled the obligations in their contracts.
"We obviously want to identify any public safety risks ... but also to ensure that what the government paid for -- through tax dollars -- is in fact what was delivered," Sullivan told The Associated Press.
In May, federal prosecutors brought the first criminal charges in the trouble-plagued Big Dig project against six men who worked for the project's largest concrete supplier, accusing them of falsifying records to hide the inferior quality of concrete.
Commuters waited years for the Big Dig to bury the city's antiquated central artery and send traffic underneath downtown. But the accident has raised new questions about the project.
Cab driver Steve Past, 45, said he drives to the airport four or five times a day.
"The drivers aren't so scared, but people sitting in the back seat are scared. Because who knows? Today one piece falls down, tomorrow another piece," he said.
Scott Brook, an 41-year-old information technology consultant, uses one of the system's main tunnels. On Wednesday, he found himself looking at the ceiling.
"I used to say that the Big Dig was the best thing to happen because it made my commute shorter, but I can't say it's such a great thing now."