driving piles through geotextile 1

[fattdad]

Please share your experiences. If the embankment is installed and grid is used to support a 1 1/2:1 slope just how practical is it to then drive vertical and battered H-piles. What are the appropriate precautions. Is there any guidance (FHWA, DOTs, AASHTO) that provides some insight?

f-d

¡papá gordo ain’t no madre flaca!

 

[MiketheEngineer]

Call the mfg??

 

[molerat2210]

Is the question related to driveability of the piles or the intregity of the reinforced slope? I never heard of a pile driven through a geogrid but I would not imagine any problem for driveability.

 

[fattdad]

sure, I'd imagine the pile wouldn't even "see" the grid. It's a question of how the driving penetration affects the function of the grid and the overall function of the reinforced soil slope.

f-d

¡papá gordo ain’t no madre flaca!

 

[FixedEarth]

Two things to consider:
1- If your embankemnt will fail in planar or surficial way, then you can measure the distance from the edge of the pile to the slope face(or where the geogrid begins) and then rerun the embankment slope analysis with the shortened geogrid length.
2- If the embankment slope will fail by rotation, then your pile (vertical or raker) will actually improve the embankment stability and there is no concern.

 

[RFreund]

Interesting... I like FixedEarth comments. It is common to have diameters up to about 18" spaced approx 6'-8' on center in segmental wall construction and there is usually no reduction in strength or wall capacity. However I maybe slightly concerned that the pile wants to pull the grid loose before the grid breaks (pull-out type failure). Then there is slack in the grid. However I'm not so sure this will happen depending on the amount of overburdened pressure.

EIT

http://www.HowToEngineer.com

 

[dicksewerrat]

How far from the surface is the reinforcement? Can it be exposed so you can watch for any damage?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[dicksewerrat]

Is it geo fabric or geo grid HDPE?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[fattdad]

I have no idea on the dimensions. I'm not even saying I'm some cheerleader for this whole idea. I do wonder about the stress concentrations in the grid when the pile is penetrating. I could imagine some wisdom where if it was a low strength geotextile it's no problem, but for the higher strength stuff, different story. I could imagine this also relating to confining stress.

I just can't quite see it happening, 'cause how do you gauge success or recognize failure?

I do get these calls though. . .

f-d

¡papá gordo ain’t no madre flaca!

 

[PilebuckEngineer]

If the slope is already built you are screwed. You can drive through the geogrid without an issue, but someone will freak out that you damaged the grid. In reality, the pile probably makes the grid stronger by anchoring it, but no engineer will buy off on that because they can't calc it. If it is grid in strips you can usually splay the straps around obstructions (piles) and then drive through them. We do that all the time when we built MSE walls and need to drill light pole shafts once the embankment is built. If I were you, I would just drive the pile through the grid. It'll bust through that fabric in no time.

 

[fattdad]

It was just a matter of time. . . I found a research project by Ryan Berg!

f-d

¡papá gordo ain’t no madre flaca!