Investigators are now saying the Big Dig tunnel collapsed because the epoxy used to secure the ceiling allowed bolts to slip or "creep" over time.
The Boston Globe is reporting that Bruce Magladry, the director of the board’s Office of Highway Safety, said the epoxy’s ”exceptionally poor creep resistance” should have been fixed when bolt slippage was noticed in 1999 and 2001 before the tunnel opened. ”It was a missed opportunity,” Magladry said.
On July 26, 2006, the Boston Herald reported it obtained documents revealing that Big Dig officials noted six years ago that epoxy ceiling supports were failing in the same tunnel section where the deadly accident occurred, but allowed the continued use of that “superglue” system to support 3-ton concrete slabs.
At the Design News webinar on June 27, learn all about aluminum extrusion: designing the right shape so it costs the least, is simplest to manufacture, and best fits the application's structural requirements.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This radio show will show what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.