Collapsed Concrete Ceiling Tiles Served No Structural Purpose (Ted Williams Tunnel)

Howie Carr ^ | 7/12/06 | Howie Carr

[Hemingway's Ghost]

I'm sure there are some decent folks in Mass, but somehow looking from here in flyover country, it just seems like a total sinkhole.

Now, that's the kind of thinking that helps those of us in the sinkhole think you people in flyover country are nothing but meth-cooking yokels. One can paint with a broad brush in both directions, you know.

Long and the short of it is this: there are great people everywhere you look. And remember, without the New Englanders that came long before you or me, there would be no United States of America.

[ncountylee]

This is the central point as far as the design goes. Have you worked on anything like this?

Nobody ever worked on a project like the "DIG." I don't have the experience to determine how exhaust should be handled but I can say that the way support was provided. almost certainly, means an add-on project.

[nascarnation]

Agree - well said
my roots are in Connecticut (Dad was born in Ansonia)

[Aquinasfan]

A Review of the Central Artery/Tunnel Project's Use of Anchor Bolts on the C05B1 Tunnel Finishes Contract

This is mind-boggling. The structural integrity of the tunnel itself may be compromised:

a letter to MassHighway, B/PB states: “[W]e feel that this practice will not have a detrimental affect on the integrity of the tunnel roof due to the probable loss of the insignificant amount of reinforcing steel." Project documents reviewed by this Office did not contain any evidence of an engineering evaluation performed by B/PB to justify its conclusion to MassHighway that the structural integrity would not be seriously compromised. The structural strength of the tunnel roof may have decreased. If the contractor drilled through or cut a number of adjacent rebars, it could affect the local structural integrity of the concrete. The subcontractors completed approximately 7,000 core drills. Potential public safety issues could exist as a result of the drilling. Despite B/PB’s assurances that no safety issues existed, MassHighway should have obtained and independently reviewed B/PB’s written analysis. This Office has taken the position in the past that the SDC should be consulted whenever a significant change is going to be made in a design or in the construction contract specifications. In this case, the tunnel designers or the SDC for the tunnel finish contract should have been asked to review the decision to cut through the rebar. The SDC, as the Project designer of record, should have an opportunity to comment on all major design changes. The SDC also provides an important check against both the contractor and B/PB. The Project unnecessarily exposes the Commonwealth to financial risk by not involving the designer. The resident engineer for this contract compared the design of the ceiling to a “Swiss watch” because of its complexity. According to the resident engineer, the ceiling design was intricate and extremely difficult to construct, underscoring the need to involve the SDC in any design or specification changes.

[Xenalyte]

"Mob" was my very first thought when I found out the substance in question was concrete.

[mewzilla]

I thought the ceiling slabs weren't there, though, for any kind of structural support? If so, does this mean that installing the concrete slabs, instead of ceramic tiles say, that the installation might have actually weakened the structural integrity of the tunnel?

[Xenalyte]

My guess is that they ran out of duct tape somewhere along the way and found some old glue to use.

Isn't it obvious? They had some Super Glue and they remembered that commercial from the '70s where the construction guy's hard hat is Super Glued to the beam and he's kicking and hanging on to the hat for dear life.

If it's good enough for suspending a construction worker, it's good enough for 6000-pound concrete.

[N. Theknow]

Didn't realize this was in the Teddy-Tube. Thought it was the Faneuil Funnel section. So much for getting to Logan quickly.

[Aquinasfan]

I thought the ceiling slabs weren't there, though, for any kind of structural support?

If so, does this mean that installing the concrete slabs, instead of ceramic tiles say, that the installation might have actually weakened the structural integrity of the tunnel?

I've heard that they're supposed to form a ventilation duct in case of a fire in the tunnel. They don't serve as a structural part of the tunnel.

But the suspended ceiling is held in place by bolts driven into the tunnel roof. The specs require the holes to be drilled to a particular depth. But since the rebar mesh is so dense, drillers hit rebar 50% of the time.

Somehow they got permission to drill through the rebar, thus compromising the strength of the concrete in the tunnel roof. This is a grave mistake, and permission to do this should never have been granted without review by the designers.

[Hemingway's Ghost]

Granted, my engineering "expertise" is limited to the naval, weapons, materials, and electrical engineering courses I took as an undergraduate at Annapolis, but for the life of me, I cannot understand how any engineer would not be concerned with the strength of a concrete ceiling after 7,000 holes were drilled into it, and the rebars giving it extra strength were cut. After reading some of the commentary from civil engineers here on FR, it seems patently obvious that this slab drop-ceiling was not part of the original plan, and that it was designed, engineered, and built almost as an afterthought. If it were not, and this type of exhaust venting was always in scope, hangers for the slabs could have been cast into the concrete ceiling of the tunnel itself---perhaps as part of the rebar, or somehow part of that system.

B/PB has blood on its hands.

[SuziQ]

I didn't think this was the Ted Williams tunnel itself. I thought it was the ramp from I-93 going into the tunnel.

[-YYZ-]

The other problem I see with this design is that the concrete panels are not actually attached in any way to their supports - they're just resting on a flange, so if one section fails and allows the panel to fall, then the supports can move laterally and allow more panels to fall off their (intact) supports. I don't know that any design of a large architectural/civil engineering type project can ever be fail-safe, but it would seem to make sense to try and design so that an isolated failure doesn't result in a chain reaction of much worse failures.

[Aquinasfan]

I didn't think this was the Ted Williams tunnel itself. I thought it was the ramp from I-93 going into the tunnel.

Similar construction, as far as I know.

[mewzilla]

I've been in tunnels with those kinds of ventilation systems. I can't recall ever seeing with concrete slabs under the plenum. I've seen ceramic tiling, though I don't know what the tiles were glued to. They're probably a pain in the heinie to replace, if you even bother, but even if a few of those land on a car, they're not going to crush anyone. Why were the slabs used to cover the plenum in the first place, do you recall hearing/reading?

[MikefromOhio]

Because (insert name of unionized subcontractor here) needed a cut of the pie.

But the order had to come from a project manager. Therefore, it's probably MORE of a case of "Well we have money, let's spend it or else we won't get it back".....

[gridlock]

Now the contractors can put in the Mother Of All Change Orders (MOACO) to take out all that concrete to replace it with something more lightweight.

Shame a woman had to die, and all, but omlette/eggs, you know?

[danno3150]

The inflated price tag, rampant corruption, poor engineering and shoddy workmanship all tend to mask the fact that replacing the existing expressway and creating a second entrance to the airport good ideas. However,this plan was in the works for over a decade before they even broke ground. By the time every corrupt politician (including Senators Orca and Flipper)got their piece of the action and every "neighborhood" effected got their own concessions, the design was obsolete. A redesign would mean going back to the very beginning and relining the pockets of the same pols. The existing expressway, like every other elevated roadway in MA, was crumbling and dangerous. So everyone decided to press on and hope for the best. The rest is criminal history. The point is that the initial plan was correct and clever, but the execution was poor and criminal. BTW - Mitt is taking some unwarranted hits on all of this. He was elected after this POS was completed. He's left with the taske of cleaning up for Dukakis, Weld, Cellucci and Swift (a tank riding moron and three RINOs)

[nascarnation]

thanks for the perspective
this project was in trouble the day it was born, sadly

[danno3150]

As history has proven time and again, even the best ideas will turn to cr*p when left in the hands of Democrats. MA is a true one party state that is infested with Dem hacks and their big labor bedfellows. There is no more glaring example of a "Culture of Corruption".

[jwalsh07]

Bad design, bad workmanship and greed. I just thank the Lord that they killed only one woman. It could have been much, much worse. And in fact will be unless they get competent engineers with no axe to grind crawling all over that architectural boondoggle.