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Hernando de Soto Bridge (I-40 Mephis) 19

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human909

Structural
Mar 19, 2018
1,900
AU
Some pretty serious looking issues here.

E1NBBdtXsAQ_Xpa_em0owc.jpg

E1NBBduWEAIJnA8_n4vt58.jpg

E1NBBduXsAAqN1p_pg4s4e.jpg
 
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From a post by ingenuity:
image_u5fry5.png

Not sure if that is 53 tones each or 53 tons total, but we are looking at hundreds of tons of added weight.If that is the weight of each plate plus the weight of the bolts they may be adding almost 1.7 thousand tons.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
Today's update:

Screen_Shot_2021-07-28_at_11.20.52_AM_pvrcla.png


Link

The posted a video on twitter of a truck driving across, apparently they are doing some load testing using the existing sensor network.
 
Does anyone have an estimate of how many tons were added to the bridge weight by the repairs?

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
Bill-
I saw it in one of the briefing documents here-Link

Brad Waybright

The more you know, the more you know you don't know.
 
"...150-ft long steel plates weighing 53 tons..."

Steel weighs about 40 pounds for a 1 foot square an inch thick.

If we assume each steel plate is 4 feet high and one inch thick, then each plate weighs 24,000 pounds--12 tons.

If there is a plate on either side of a beam, and there are two beams, it is looking like the 53 tons is the total for all four pieces.


I will guess the nuts and bolts will add another 3 tons.

spsalso
 
I found the press release regarding added weight:

June 25, 2021

"108,000 pounds of structural steel plating added to the tie girder"

So ya got 54 tons. Not "hundreds of tons". Not "1.7 thousand tons".

In reading those rather neat press releases, it looks like they might also have been removing some steel.


spsalso
 
ENR Southeast said:
Though no additional damage was found on the bridge, in-depth inspections indicated that the structural load at the fracture had been shed to the remaining web and flange sections, putting those components under exceptional stress.

“We needed to understand that better before we started yanking around on the bridge, trying to move things back to where they were,” Stover says.
That prompted the thought;
"Lesson learned from the FIU pedestrian bridge collapse."

--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
An interesting item in the article referenced by MintJulep was the rather short comment about how drones were used in the inspection as well as being able to livestream their video back to the design office working on the proposed repair effort. I would expect that we'll be seeing more of this sort of thing in the future.

With respect to drones being used to inspect damage, the first time I saw this being mentioned to any degree was in 2014 after the 6.0 magnitude earthquake that hit Napa, California. The news spent a fair amount of time talking about and showing videos from drones that were used to inspect the damage to buildings, particularly masonry buildings, before building inspectors were allowed to physically enter these same buildings. At about that same time there were stories about how power companies were also starting to use drones to inspect high-tension power lines, a job that used to done my people suspended for helicopters.

Anyway, it was an interesting comment, I just wish they would have included more details about how the drones were used and what lessons they learned about their use and practicality.

John R. Baker, P.E. (ret)
EX-'Product Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
From the ENR article, 216 thousand pounds. 108,00lbs plus two other quantities. The ENR website allows one complimentary visit and I can't go back and recheck but I remember adding the quantities up to a total of 216,000 lbs. That is only three 18 wheelers at 72,000 lbs each.
That is a very old weight limit, most semis are heavier than that today.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
"A crack in a steel beam that forced the closure of the Interstate 40 bridge connecting Arkansas and Tennessee for three months likely began when the span was fabricated in the 1970s and went undetected for years, a report by Arkansas' Transportation Department released Thursday said."

Update

Link

 

"The fired inspector had missed the crack in 2016, 2017, 2019 and 2020. Another inspector who had missed the crack in 2018 had never inspected that portion of the bridge before, and the department said he has been “verbally counselled” and will receive additional training.

The department’s report said the agency’s failure to adequately respond to employees concerned with the fired inspector’s job performance “perpetuated a culture where team members did not feel they had the authority or support to question a lead inspector’s procedures or thoroughness.”"
 
No criminal charges?

Failure to deliver honest services?

I ain't impressed.


spsalso
 
His supervisor's won't be pushing for charges. A defence of inadequate training and oversight will not have positive repercussions on their resumes.
Actually, if the report is to be accepted as to the numerous management shortcomings and subsequent changes to the bridge inspection program, the inspector may have a case for wrongful dismissal. Possibly not a strong case, but.....

--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
Sounds very similar to the scapegoat that's been targeted in the Boeing MAX fiasco.

I am sure he will sue at some point and retire early as a happy man. And all the MBA's will keep their bonuses as will he.
 
Good morning, everyone.

I work and live in Memphis, Tennessee. I work as a maintenance director for a nursing home.

I come here today to learn or try to find out, if the repairs they did to the Hernando-DeSoto Bridge are permanent and is good or as good as before?

Is it possible that the load that was intended to bear weight on the damaged beam was transferred somewhere else and possibly causing the integrity of that location to be impacted negatively?

Any idea the estimated remaining lifetime of the bridge, as-is right now?

Thanks in advance for any feedback.

 
I'm not sure anyone can answer that. The integrity depends on the Work undertaken/completed. An estimate of the remaining lifetime is not posssible, IMHO. [ponder]

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
This is considered a permanent repair, at least as long as frequent periodic inspections don't show anything untoward. Most of the damaged steel was removed and where that wasn't possible additional support and bracing was added.
Additional information here Link

Brad Waybright

The more you know, the more you know you don't know.
 
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