Bridge collapse during concrete pour

[Cool_Controls]

Link

 

[Sym P. le]

Condolences to the families. This should never happen.

AP

Google Earth 39°21'37.91"N 94°18'55.62"W

 

[spsalso]

That's a pretty impressive bridge for a little backwoods two lane (gravel?) road.

Or are my eyes not properly calibrated?




spsalso

 

[TugboatEng]

Maximum cost for maximum infrastructure subsidies?

 

[Sym P. le]

I was thinking it's an expensive way to build a bridge.

 

[MortenA]

Im not a civil engineer but from the news press i see that this type of collapses occurs quite often.

--- Best regards, Morten Andersen

 

[dragon6172]

Amazing that Google Street View image was from this month.

 

[spsalso]

I see the road is a paved road, and that the bridge looks smaller from this angle.

The overhead view shows the original, a through pony truss with a wood deck.

Here's a link for the old one:

https://bridgehunter.com/mo/clay/16029/

Yup. Quite the cutie, though I can see that a replacement might not be unreasonable.


spsalso

 

[Brian Malone]

https://www.mycouriertribune.com/ne...cle_8c98b864-5597-11ed-bde4-0f4883dc0d38.html

 

[WinelandV]

Somehow I missed this - yikes. Hits close to home because I used to do bridge falsework design in my first position.

Reading the Courier Tribune article, some poor 3rd party inspector just got thrown under the bus. It's highly likely that inspector was only checking rebar layouts. In my experience, Formwork and Falsework pre-pour inspections were handled by the designer of those items. Given the size of the construction company, I doubt they have an in-house engineer for this.

I'll be interested to see if there was an issue with the sequencing/placement of the concrete, or if there was an issue with the construction of the falsework, or if the falsework design was insufficient.

Please note that is a "v" (as in Violin) not a "y".

 

[Lomarandil]

I was just about to say that windlandv.... I agree that WSP was likely checking the permanent rebar.

Lehman construction is moderately sized -- they might not have a stamping PE on staff, but depending on the MODOT specs they might not have needed one for this bridge falsework.

If I had to issue a way-too-preliminary guess, I'd be taking a look at the ground support condition under the shoring towers.

 

[Brian Malone]

This follow-up story has two photos of the collapse scene:

https://www.mycouriertribune.com/br...cle_73fdaf2e-562a-11ed-bf08-373b142f6ec5.html

 

[WinelandV]

depending on the MODOT specs they might not have needed one for this bridge falsework

With the company I worked for, bridge falsework was always at least "moderate risk" no matter the bridge size, so that required a PE seal and inspection by someone in the company who was deemed qualified (this frequently ended up being a plane for whoever at the office designed it the falsework). Even if you could use a standard spec, I'm surprised MoDOT wouldn't have required someone to seal the falsework design. --But maybe it wasn't required because MoDOT wasn't involved since it was "just" a bridge on a county road.

Good call, Lo, on the ground conditions under the towers. I do wish that the photos were a bit closer, and from ground level, so that we could really conjecture wildly.

Please note that is a "v" (as in Violin) not a "y".

 

[Qshake]

Collapsed bridge is two lane and a three span with extended pile bents as intermediate bents. The superstructure was a slab bridge which is not hugely uncommon in the state. But most likely used because it's likely a low water crossing. So the shallow slab superstructure allowed more freeboard.

While you can see the forming for the deck, you can't really see much in the way of falsework under the bridge and spanning the creek. Not to say it isn't there but just that the photos are limited at this point. Also lots of rain in the past few days may have contributed to the failure not only for falsework but for fixity for extended pile bents.

Horrible for all involved.

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

 

[bugbus]

Why is the epoxy coated rebar on one half only?

 

[Sym P. le]

Because they were 50 percent complete pouring concrete.

 

[Cool_Controls]

I would assume it was all epoxy coated and the grey rebar is coated in concrete. When the false work collapsed that concrete flowed away, leaving the grey rebar.

 

[bugbus]

Good point

 

[Factoter]

Above aerial looks to be a concrete pumping truck hiding under those sticks, directly under the excavator’s boom? This big mass could be contributor to a lateral failure of piles. Any other images out there?

 

[Qshake]

The concrete pump is green and is outside one of the abutments. See this link.

https://www.nbcnews.com/news/us-news/1-dead-3-injured-missouri-bridge-collapses-rcna54260

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.