Indiana I-65 bridge settlement
Indiana I-65 bridge settlement
(OP)
Check out this ENR article.
http://enr.construction.com/infrastructure/transpo...
The explanation of the problems cause sounds fishy.
What the heck is "compressed gravel" or "watertight soils".
Also what is an "artesian water pocket"
Sounds like amateurs describing a feature that is pretty new to me.
http://enr.construction.com/infrastructure/transpo...
The explanation of the problems cause sounds fishy.
What the heck is "compressed gravel" or "watertight soils".
Also what is an "artesian water pocket"
Sounds like amateurs describing a feature that is pretty new to me.





RE: Indiana I-65 bridge settlement
The ENR story says that inspectors have been reporting settlement of Pier 3 for 10 years. The substructure was rated "poor" in May.
I looked up the prime contractor "Walsh Construction Co.". They appear to be a large experienced firm with a long record of successful bridge projects. I wonder if they sent their amateurs to handle this project?
1. One thing my father taught me: Do your foundation (substructure) work first, at least until it is above ground / water. On this widening job, the Contractor appears to have detoured traffic, removed necessary parapets and bridge deck, roughened the surface of existing piers... then started work on the footings.
2. The bridge had settlement problems, but notice in the following photo that the traffic detour and parapet / deck removal are putting eccentric loading on the existing footings:
3. The eccentric loading is in the opposite direction than the "lean"... or is it? At least one girder is "off its rocker" (IMHO, Contractor too). Is the entire pier settling with the "lean" caused by a combination of pier settlement and the missing rocker? In the following photo notice that much of the deck, not just the edge appears to have settled:
As usual, there is likely much more to this story and much of my speculation will be flat wrong. I do believe the bottom line is that this problem will not be "fixed" by mid-September. I'll come back here and "eat crow" if it is.
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RE: Indiana I-65 bridge settlement
Further, the pier is incredibly thin in the direction of traffic. Odd.
Yep...mid-September is a dream.
RE: Indiana I-65 bridge settlement
Jest pour a lot of very wet, high-slump grout mix right over the top of the drooping section of the bridge deck. The concrete evens out into the low parts of the deck = you end up with a flat upper surface. Let the concrete dry, the repaint the stripes. 8<) /sarcasm
RE: Indiana I-65 bridge settlement
Why did the problem surface now?
The construction work, unique soil conditions and an "artesian water feature" -- a pocket of water under high pressure beneath pier #3 -- combined to create the problem, Wingfield said.
The pocket of water will move and cause a shift in the sand and compacted gravel underground if there's a change in pressure, INDOT Bridge Design Manager Jeremy Hunter added.
Pier #3, located at the center of the five-span bridge, began to move and settle on Monday, Aug. 3 after the contractor began driving pilings to widen the pier to support the additional lane, he said. The pier settled 9 inches between Wednesday night and Friday afternoon, officials said.
Could the problem have been avoided?
Prior to the start of construction, INDOT and the contractor's engineers researched bridge inspection reports to anticipate what they might run into, Wingfield said.
They knew the southwest end of pier #3 had settled into the creek channel years ago.
That didn't raise any red flags during decades of monitoring, said INDOT Director of Bridges Anne Rearick.
"It wasn't continuing to tilt," she said. "There was no noticeable change."
RE: Indiana I-65 bridge settlement
From this recent DOT report, it would appear the footing did not have any piles under it, an unusual thing for a bridge over a creek. That sort of explains settlement while driving sheet piles nearby. Boy the fishy language is hard to believe.
RE: Indiana I-65 bridge settlement
RE: Indiana I-65 bridge settlement
Bill
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"Why not the best?"
Jimmy Carter
RE: Indiana I-65 bridge settlement
Walsh is a big sophisticated outfit. They're not going to eat this for goodwill.
RE: Indiana I-65 bridge settlement
RE: Indiana I-65 bridge settlement
1. The original 1969 bridge plans, including geotechnical information performed then. (Spread footing are pretty small.)
2. The plans for the 1988 bridge modifications. (Replace aluminum hand rail with concrete Jersey Barrier - adding some dead load).
3. The complete 2014 geotech report and recommendations.
4. The conceptual design-build plans for the current project.
Some eye openers too:
Scour elevation is 5 feet below the bottom of the footings!
Piles are proposed... despite the above warning about limiting the depth of construction excavation, the conceptual drawings show the bottom of the interior pier pile caps at the same elevation as the bottom of the adjacent existing interior pier footings!
This is hard to believe!
I have attached a 10 Megabyte .zip file with pertinent excerpts from the 1969 and 1988 plans plus the complete 2014 geotech report and current design-build conceptual plans.
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RE: Indiana I-65 bridge settlement
Seems the DOT, the Contractor, and now the Geotechnical Engineer are "off their rockers".
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RE: Indiana I-65 bridge settlement
RE: Indiana I-65 bridge settlement
RE: Indiana I-65 bridge settlement
There will not be much room to drill the mini-piles through the existing footing. That footing projects 9" beyond each end of the pier and just 4'9" beyond each side. The footing is only 2'6" thick. Wonder how much footing rebar will get cut when the mini-piles go thru?
The 1969 maximum footing soil pressure is shown as "3.5 tons / square foot". What are your thoughts on that figure?
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RE: Indiana I-65 bridge settlement
As to mini-piles, I'd suspect they will be alongside the narrow footings and a new pile cap would be built over them, tied into the pier somehow.
but, with the one boring showing artesian conditions all the way down to 100 feet or so, it would seem that there should be a decision by the DOT to use H piles to support the existing piers as well as any new work. Driving H piles with low head room will be interesting. Hope the welder has a lot of rods or wire electrodes.
I think someone in authority should take over this thing, sit back and think it out before proceeding. I'm wondering if the consultants really are qualified for something like this. It is a very unusual site. The deep depth artesian factor may well cause another failure otherwise. It's not in a "confined" layer.
RE: Indiana I-65 bridge settlement
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RE: Indiana I-65 bridge settlement
Anyhow this TV station made this announcement today.
http://www.wbiw.com/state/archive/2015/09/indot-cr...
RE: Indiana I-65 bridge settlement
video shows the blocking
RE: Indiana I-65 bridge settlement
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RE: Indiana I-65 bridge settlement
RE: Indiana I-65 bridge settlement
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