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Goner Message Board / ???? / Dear Sambeaux,
Posted: Jun 24, 2011 9:16 am
 
As I write this there is a pile driving machine outside of my office window driving 70 foot pilings into the ground. Interestingly, these are iron pilings. Some are hollow cylinders and some of them are i-beams. This results in a nice, headache inducing BOIOIOIING noise that follows each BAM.

My question is, doesn't iron decay pretty quickly when it is submerged in muddy soil? It seems like a poor choice of material to me. I realize the lifespan of timber poles, even when pressure treated or doused in creosote, is probably not great either. But given the expense it seems like iron wouldn't be much better.
Posted: Jun 24, 2011 9:29 am
 
i like garage rock! gobble gobble! kind turkey, brah!

carry on.
Posted: Jun 24, 2011 10:05 am
 
i have Creosote's first single, before the AmRep courtship began.
Posted: Jun 24, 2011 10:06 am
 
Posted: Jun 24, 2011 10:55 am
 
Funny you should ask this. I've been working a lot with piling the last few weeks. And we were talking about this at work, specifically with regards to a cement poo-water tank at a local waste water treatment plant.

None of us are metallurgists here at work, but our hypothesis is that it's the free oxygen which causes the oxidation and you don't get a lot of that when metal is completely submerged or buried.

The i-beam shapes are actually h-piles, made of HP shapes (different than the traditional W, WF, S, or M shapes that are traditionally associated with i-beams). These HP shapes better approximate squares. The pipe piles are pipe shapes (with the standard nominal size = O.D., rather than a round tube shape generally has a larger O.D. than the nominal shape that describes it).

We're using a combination of HP and pipes on the dock facility I'm doing just north of New Orleans. Most of the river piling is pipe and a special grade of weathering steel (ASTM A606) that forms a sacrificial rust coating so as to slow or prevent complete corrosion over time. Typically though, it's a regular carbon steel, when the pipe or HP is completely buried or submerged.

Cathodic protection is common on ship hulls. When I used to go on drydock inspections, they'd have little blocks of zinc that would be strapped to the ship hull every so many feet. Many of these would be completely dissolved after the typical 5 yrs of service between drydockings.

Also though, on some bridges we're doing up here, we're using square concrete piling (14"x14"x35' long) under the bridge abutments and bent foundations. The contractor has asked us to approve a design for steel piling to use in place of the concrete because its easier/quicker for him to install (although the per foot cost is more expensive). It's also a fuck of a lot easier to field splice in case he fucks it up.
Posted: Jun 24, 2011 11:26 am
 
dude, goner is THE SHIT, man.
Posted: Jun 24, 2011 11:34 am
 
speaking of the shit, I hate piles
Posted: Jun 24, 2011 11:36 am
 
what about gomer's pile?
Posted: Jun 24, 2011 12:10 pm
 
I've been working a lot with piling the last few weeks.

I LOLed.
Posted: Jun 24, 2011 12:40 pm
 
Posted: Jun 25, 2011 9:14 am
 
our hypothesis is that it's the free oxygen which causes the oxidation and you don't get a lot of that when metal is completely submerged or buried.

I thought the same thing, but does not a metal hulled ship on the ocean's floor decay? Does not the railroad spike found buried in dirt by a child's metal detector look like a rusted turd? I once found an iron boat anchor submerged in fresh water that literally crumbled once on dry land. Curiosities abound.
Posted: Jun 25, 2011 9:58 am
 
does not a metal hulled ship on the ocean's floor decay?

Water's full of oxygen.
Posted: Jun 25, 2011 9:59 am
 
Does not the railroad spike found buried in dirt by a child's metal detector look like a rusted turd?

Not really that deep.
Posted: Jun 25, 2011 1:16 pm
 
Curiosities abound.

BRASSIVATION
...
=-AY!
Posted: Jun 25, 2011 5:44 pm
 
Look at the Titanic. That shit has been down there for years and it still looks alright. What about your boat anchor? Cool in water, not so cool on dry land.

The weathering steel of which I speak.

Water's full of oxygen.

Yeah, go try breathing it dumbass.
Posted: Jun 25, 2011 5:52 pm
 
Also:
http://www.geoforum.com/info/pileinfo/corrosion.asp

Don't know if they're talking in millimeters/year or some other euro-measurement (because the first m in mm is some other, smaller font).
Posted: Jun 26, 2011 5:02 am
 
Micrometers? 10^-6. Maybe my browser or their word processor can't process the Greek "mu"?
Posted: Jun 26, 2011 6:25 am
 
Ok, I believe you.

"Pile Info" is my new favorite site.
Posted: Jun 27, 2011 3:26 am | Edited by: tigerblinds
 
On time me an my dad built a 20 foot creosote fence on a 105 degree summer day...and didn't wear any gloves....the next day we had 2nd degree burns on our hands and forearms....

I learned never to fuck with creosote anything ever again.
Posted: Jun 27, 2011 3:28 am | Edited by: tigerblinds
 
I like iron, but then again my DNA mostly comes from Northern Germany Tuetoburg Forest Norse country.
Posted: Jun 27, 2011 3:33 am
 
Okay I've still only read half this thread, but I do know that they cover iron frame work in tar because rust is realy a form oxidation, and when you cover something in tar oxygen can't get to it....it's also a fire prevention measure...

Uh yeah, some of my other DNA comes from construction workers.
Posted: Jun 27, 2011 3:39 am
 
Oh yeah, if they pulled the Titanic out of the water it would decay rapidly....when metal is in salt water, the salt and oxygen cause something different than normal rust...other factors are the quality of the metal and the ph balance of the water....I'm familiar with this shit from my stint on the equator....

But back to tar, you dip somebody in that shit and then poor feathers on them and that's a comedic way to kill them, because skin needs oxygen too...I know that from my stint in the south.


I say they pull the fucking Titanic out and bondo that shit.
Posted: Jun 27, 2011 4:32 am
 
when you cover something in tar oxygen can't get to it.

Yeah, if somebody can't afford weathering steel on river pilings, they use the regular carbon steel and coat it with tar. Check it.
Posted: Jun 27, 2011 6:15 am
 
Tar seems like a poor choice for fireproofing.
Posted: Jun 27, 2011 6:17 am
 
Yeah, I think they're only using the tar for fire protection in tigerblinds' world.
Posted: Jun 27, 2011 6:31 am
 
Oh yeah, asbestos is a good alternative for fireproofing....but what do you think makes that foamy shit they spray on the steel stick?...I'd get that wrong on jeopardy so what?
Posted: Jun 27, 2011 9:14 am
 
what do you think makes that foamy shit they spray on the steel stick

I think it's typically a proprietary adhesive.
See these specs: http://www.wbdg.org/ccb/DOD/UFGS/UFGS%2007%2081%2000.pdf
from the govt.'s Unified Facilities Criteria. Specifies NOT ASBESTOS, stuff is typically gypsum or some other mineral fiber (that's not asbestotic).

I ain't faulting you. People do tar pipes, to prevent corrosion, but not to fireproof is all.
Posted: Jun 27, 2011 9:43 am
 
Don't worry no offence taken. I'd miss every question on Jeopardy for not answering in the form of a question.
Posted: Aug 19, 2011 4:22 am
 
I discovered more about this yesterday when I saw them using the pile driver to PULL THE BEAMS OUT OF THE GROUND! It was pretty cool.

Talked to some other people and it turns out they drive temporary pilings which are then fitted with a giant weight on top to test the integrity of the bedrock/shale/what-have-you underneath. If the weight sits there for a month or so and doesn't sink, then I guess they start driving regular wood pilings. Ugh. Not looking forward to that.
Posted: Aug 19, 2011 8:16 am
 
first time seeing this thread. nice one.
Posted: Aug 19, 2011 11:40 am
 
turns out they drive temporary pilings which are then fitted with a giant weight on top to test the integrity of the bedrock/shale/what-have-you underneath

Up here, they may even drive steel pilings to do that (and pull them back out) and the Tenn Dept. of Trans. allows them to do it over the course of an hour for bridge projects. They increase the load incrementally until it reaches 200% design load and then they back it off at the same rate they increased it. If it doesn't exceed a certain deflection or if it doesn't continue sinking when no additional load being put on it, then you can deem that an acceptable depth to drive the rest of the piling. You measure the bearing for all the rest of the piling under the specific structure by how many hits with the big X-ton hammer to drive it a foot down ("blow count", a blow count of 10 means it took 10 hammer drops to drive it a foot).

They did the kind of load test that you're describing at the new Playhouse up here at Cooper & Union. Shit sat there for a month.

Yeah, you're fucked, but the steel pile they already drove was a production pile so you're one down.

bedrock/shale/what-have-you underneath

You won't be hitting any of that. Best you can hope for up here and down in NOLA is a layer of sand. There's an estimated 400' of alluvial deposit in the MS River basin -nobody knows how deep it really is. But in Nashville they can reach bedrock in like 50' or less.
Posted: Aug 19, 2011 1:14 pm
 
But in Nashville they can reach bedrock in like 50' or less.
sweet, how are fred and wilma?
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