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

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

[mewzilla]

Their purpose is strictly aesthetic.

And the feds didn't have a cow about this, why?! I mean US taxpayers are only picking up 60% of the tab for this charlie foxtrot.

[Jim Noble]

Now, they're going to get to remove all of those panels, I'm betting.

No takers.

The panels will all come out.

The big question is, what's next?

[Jim Noble]

Who will be held responsible for this fiasco?

Bush.

[Aquinasfan]

I still maintain, though, that it is the design that is at fault here. Any design that suspends concrete panels like this one is going to suffer failures at some point. It's inevitable. A small water leak will corrode fasteners faster and anyone would believe, and can weaken the concrete itself.

Yes. And even if you're going to go with a ceiling like this, the slabs should have been resting on an I-beam frame with I-beams on the sides to transfer the load to the ground.

Someone on the other thread said that the airspace above the ceiling was supposed to be used to vent fumes in case of a tunnel fire. But I can think of many other safer and less expensive ways to do that.

[Aquinasfan]

Fast forward through numerous screwups at testing, highfailure rates, slow pace of constructions, finding crews had cut the lenghts of bolts to make them fit in the rebar grid, and huge change orders regarding the drilling of holes and installation of the anchors. The project manager allowed anchor holes to be core drilled THROUGH the rebar without consulting the original designers of the concrete roof.

This is GROSS negligence. Heads have to roll for this.

Precast ceiling panels can be hung without any problem whatsoever.

I still think the design is horrible. I've never seen concrete air ducts used anywhere. Why not steel ducts, or lots of steel ducts? They could have used much smaller fasteners.

Even if they were using concrete ceiling panels, why didn't they build a grid out of I-beams? They could have rested the slabs on I-beams and then transferred the load to the ground with vertical I-beams on the sides.

[nascarnation]

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.
Prayers for the family of the woman who was killed.
That slab could have just as easily wound up on a whole bus load of kids.

[Aquinasfan]

wearing a hard hat in those circumstances is kind of a twisted joke.

Yeeeeaaah... I sure as hell wouldn't walk through there.

[Aquinasfan]

"I know that epoxy can be stronger than steel, so that wasn't necessarily the problem."

No, it can't.

I guess you're right. It's very strong though, and I have to assume that it's got better shear strength than concrete.

[HamiltonJay]

If they served a structural purpose they wouldn't be Hanging from the ceiling and up by ties.. while you can bolt segments into rock to form walls and ceilings of tunnels... this is clearly not what these were.... A failure of a single bolt in that sort of situation would not cause an entire segment to fall, let alone a cascade effect that would bring down other segments as well.

I can tell you this, the damned thing needs filled in with grout and written off.... It was clearly built substandard with graft being its top priority.

Its time Blue Staters started to wake up to the government they have, because its the government they deserve... You keep voting the way you do, and enjoy the communist world you are creating.... Where your life is worthless, and inept running the show do so with impunity. As someone who grew up in the south it always amazed me how they portray the south as a good ole boy network.... when I've never saw the complete corruption and control I have seen since moving up north.

Today in Pittsburgh an overheight truck entered the ft pitt tunnels and knocked a few tile loose... but no one died, the tunnel didn't fail or collapse.. and that tunnel is old, though recently refurbished... Now I'm not defending PA as a state with its head completely screwed on right.. but this incident resulted in a half hour closure to make sure no other problems and traffic resumed... no injuries or deaths.. WHICH IS WHAT YOU WOULD EXPECT.... I guarantee this had happened in part of the big dig, the outcome would not be the same.

[Aquinasfan]

If the "dead" space was needed for exhaust reasons, as mentioned, hanger straps would automatically been designed in.

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

[meema]

bttt

[VRWCtaz]

"When you name something after Ted Williams, expect things to come to a head..........."

You have an interesting sense of humor.

[finnman69]

Lets be clear, the report was from 1998, and was early on in the project. The area of tunnel that collapsed might have had none of the issues in the report.

[Red Badger]

Eye will leaf know pun un-dun.....

[VRWCtaz]

Now you're just trying to show off.

[finnman69]

Concrete is excellent in compression but has zero strength in tension.

Epoxy anchors are fine if the hole has been properly cleaned out and you have a good bonding surface, and the anchor is allowed to properly dry.

[freedomlover]

"I don't know about this, even a potatoe dropped for an overpass onto a speeding car can kill. So lightweight items can kill just a well as cement... "

I understand lightweight items don't fall as fast, so based on my understanding of dynamics the damage will thus be less.

Right?

(note I argued with you on the issue rather than critizing you on bad spelling)

[Red Badger]

http://www.justanyone.com/allanguish.html

[Robert A Cook PE]

"Hurricane force winds" might be a reference to the sudden wind gust from a 18-wheeler (truck trailer) going by 3-4 feet underneath the suspended panel at 70 mph: Of course, most of the time, the truck traffic is backed in the tunnel so 3 mph is a better speed estimate, but still.


IF that were the case however, then SIMPLE vertical bolts would immediately begin cracking and vibrating out from their holes by the repeated shaking of the 3 ton panels. So the designed failure was overbuilding (overspecifying) the PANEL load requirements by demanding they resist a repeated 70 mph wind gust, while designing the panel suspension bolts to resist a static simple vertical load.

Then of course, finding out that the installing crews didn't drill out the bolt holes deep enough ....

[Robert A Cook PE]

14 billion in American taxpayer money goes to Boston to

(1) bury an existing expressway, but not enlarge it

(2) buy a park straight through the middle of what's nearly yhe oldest city in the northeast.