Panel faults Big Dig glue; `This was a failure to understand epoxy creep'.Byline: Andrew Miga WASHINGTON - In the year since a Big Dig Big Dig or The Big Dig may refer to:
Yesterday, a federal safety board singled out a cause it said many people had failed to understand: inadequate glue used to secure the 4,600-pound tunnel ceiling panels. The July 10, 2006, collapse that killed Milena Del Valle, 39, could have been avoided if designers and construction crews had considered that the epoxy epoxy Any of a class of thermosetting polymers, polyethers built up from monomers with an ether group that takes the form of a three-membered epoxide ring. The familiar two-part epoxy adhesives consist of a resin with epoxide rings at the ends of its molecules and a curing holding support anchors for the panels could slowly pull away in a phenomenon known as "creep," the National Transportation Safety Board concluded. "This was a failure of understanding of the phenomenon of creep," said NTSB NTSB abbr. National Transportation Safety Board chairman Mark V. Rosenker. When evidence of problems with the anchor system arose, engineers and others overseeing the Big Dig focused on installation problems rather than taking a hard look at the epoxy, the NTSB said. The investigation showed 20 anchors pulled out from the tunnel roof, sending about 12 tons of concrete and steel crashing down as the Del Valles drove through Interstate 90 toward Boston's Logan Airport. The board spread blame with a broad brush: The Massachusetts Turnpike The Massachusetts Turnpike (commonly shortened to the MassPike or The Pike) is the easternmost 138-mile (222 km) stretch of Interstate 90. The Turnpike begins at the western border Massachusetts in West Stockbridge connecting with the Berkshire Connector portion of Authority contributed to the accident by failing to implement a timely tunnel inspection program that could have identified problems in time to prevent the accident. State officials have said the anchors were only inspected once, immediately after they were installed in 1999. Powers Fasteners fasteners In construction, connectors between structural members. Bolted connections are used when it is necessary to fasten two elements tightly together, especially to resist shear and bending, as in column and beam connections. Inc. provided "inadequate and misleading" information about its Power-Fast epoxy. Tests had shown the epoxy's "Fast Set" formulation to be "subject to creep under sustained tension loading." The company denied it was at fault. Modern Continental Construction Co. and Big Dig project manager Bechtel/Parsons Brinckerhoff failed to properly monitor known problems with the adhesive anchors. The companies say they stand behind their work. Bruce Magladry, director of the NTSB's Office of Highway Safety, said there was no malice among those who built and oversaw the Big Dig. Gov. Deval L. Patrick said the NTSB report is a stinging rebuke for the project's past management. Attorney General Martha Coakley Martha Coakley (born July 14, 1953 in Lee, Massachusetts) is the Attorney General of Massachusetts. She was sworn in on January 17, 2007. The former District Attorney of Middlesex County, Massachusetts, having served from January 1999 to January 2007, she was the District Attorney is expected to announce soon whether she'll press criminal charges in connection with the accident. NAME: CENTRAL ARTERY/THIRD HARBOR TUNNEL Harbor Tunnel has the following meanings:
ART: PHOTO CUTLINE: A Massachusetts State Police officer stands next to a pile of bent bolts placed on a barrier. They were removed from the Big Dig tunnel after the July 11, 2006, fatal accident involving a ceiling collapse. PHOTOG pho·tog n. Informal A person who takes photographs, especially as a profession; a photographer. : AP File Photo |
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