Big Dig designers asked to reduce bolts
Big Dig designers asked to reduce bolts
(OP)
A new ENR news clip on the big dig fiasco. Apparently, someone coerced the designers to reduce the number of the bolts in the connections from 4 to 2. But I know I saw the photos of the plates with 4 epoxy bolts hanging out so I don't understand this story:
http:// enr.constr uction.com /news/othe rsources/a rticle.asp ?SMDOCID=a fx_2006_09 _18_COM_04 15-1459-MG T_GOV_USA_ _&SMCo ntentSet=0
http://






RE: Big Dig designers asked to reduce bolts
RE: Big Dig designers asked to reduce bolts
"Unless I'm missing something, I don't see why (the ceiling designer) requires a 4 bolt anchor plate when a 2 bolt anchor plate would be sufficient," Robert Richard of Bechtel/Parsons Brinckerhoff wrote.
Richard's memo, dated June 23, 1998 and addressed to Gary Baxter, also of Bechtel/Parsons Brinckerhoff, said Gannett Fleming should either cut the number of bolts in half or submit calculations "proving that 2 anchor bolts do not work," the newspaper reported.
Gannett Fleming officials agreed to reduce the number of bolts, calculating that the ceiling would be safe "assuming proper installation and quality of the product materials," according to a company statement."
OK, so it looks like calculations were submitted proving that two bolts would work. What's the problem?
Bechtel/PB and Gannett-Fleming aren't rookies and don't hire people who are intimidated by much of anything (it's the other way around, in my experience). If there's money to be made, they make it and if a real savings - without compromising safety - could be realized, then they are 100% within their right to make it happen.
Let's see the calcs and not let the Boston Globe tell us our business.
Be that as it may, if this turns out to really be something akin to the Hyatt-Regency, then their heads should roll.
RE: Big Dig designers asked to reduce bolts
RE: Big Dig designers asked to reduce bolts
My problem with the design is that it is difficult to install epoxy anchors overhead and acheive reliable repeatable results. My other problem is that the five points of connection all had turnbuckles, making it impossible to determine how much load was in each connection.
A very intersting topic to follow.
RE: Big Dig designers asked to reduce bolts
I remember seeing photos of plates with four holes. You don't suppose they installed two bolts in these plates...
RE: Big Dig designers asked to reduce bolts