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Re: big dig structural failure - epoxy anchors overhead supporting gravity

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> From: "S. Gordin" <mailbox(--nospam--at)sgeconsulting.com>

> no redundancy.  Heavy permanent loads, likely dynamic loads (it was =
> written somewhere that the ceiling was that heavy to prevent vibrations) =
> - it should look very uncomfortable (to say the least) even on the =
> plans. =20

There's a pressure wave that moves ahead and behind a vehicle in a
tunnel. One article indicated 100k vehicle trips per day.

> From: "Gerard Madden, SE" <gmse4603(--nospam--at)gmail.com>

> Look at those 4 dinky bolts MAYBE 6" long total holding a thick WT with huge
> clevis.... no wonder.

One certainly has to wonder about the design criteria for component
selection and sizes. It doesn't look balanced, but, possibly:
- rods selected for axial strength or stiffness
- clevis sized to suit rods
- WT sized to suit clevis
- anchors selected for actual forces
However, it appears to be the epoxy interface that exceeded as-built
capacity, not the threaded rod.

Gotta laugh and cry at the commentary provided in Toll Road News. The
writer proposes certain direct threaded or expansion anchor options,
available at the corner hardware store, as being more viable/appropriate
selections. They have already determined the problem and solution.

Here's another type of newspaper quote that we hate to see (Boston
Globe):
"One construction industry specialist said he questioned whether the
drop ceiling in the turnpike tunnel was needed at all. Turnpike
officials said yesterday that the drop ceiling was needed to improve the
flow of fresh air into the tunnel and move exhaust fumes out. But the
specialist, who is familiar with the connector tunnel design but asked
not to be identified, said the drop ceiling was there mainly for
aesthetic reasons, to hide fans. He said the section is vented by open
air entrance ramps only about 200 feet away."

A Construction Industry Specialist? Design engineer, Construction
Engineer, Site Labourer?

In both cases there is no analysis. Potential professional misconduct or
negligence if an engineer is speaking. Dangerous: politically because
it's published; professionally because it broadly suggests that the
engineering was inadequate and that lands on you and me.

-- 
R. Paul Ransom, P. Eng.
Civil/Structural/Project/International
Burlington, Ontario, Canada
<mailto:ado26(--nospam--at)hwcn.org> <http://www.hwcn.org/~ad026/civil.html>

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