LPILE to analyse non reinforced concrete piles???

[jgd2]

I was wondering if anyone knows LPILE can analyse non reinforced concrete piles?

 

[jdonville]

jgd2,

Lpile will do it. You will need to input pile cross section.

You may wnat to look at Section 22 of ACI 318-08 for design flexural capacity of plain conrete.

J

 

[jgd2]

J,
I do not see any option for non reinforced concrete in the pile shape input section. If I put 0 for reinforcing bar value and run the analysis, it gives me some weird lateral deflection curve with -44 in pile head deflection. Am I missing something here?

thanks

 

[ishvaaag]

Try to cheat it with 0.00 in^2 rebar to see if you get the same.

 

[PEinc]

Without reinforcing, the concrete pile probably is failing in tension due to the bending force. If you have bending, you should provide reinforcing.

http://www.PeirceEngineering.com

 

[ishvaaag]

0.0001 in^2 or so, this hard keyboard...

 

[jgd2]

Ishvaaag,
It did not work that way. Someone suggested to pick type 1 analysis from the options menu and that worked. In type 1 analysis, you do not have to input reinforcing steel.

thank you all for your response.

 

[ishvaaag]

The only thing remaining is to see what stiffnesses (and large displacement?) are being assumed that give such displacement. It is quite easy, anyway, to ascertain what moment will initiate crack propagation, the one that overpowers the assumed tensile strength in the concrete; this you can do with any compatibility of deformations package for sectional analysis able to do the check. Initiation of crack without nothing to restrain it is failure, yet there is in this case lateral support by the soil ... maybe this is what the package is acknowledging ... but wold be as well rare since 44 in is again failure in the soil.

 

[SlideRuleEra]

Regardless of the LPILE results of the installed pile, an unreinforced concrete pile (of typical useful length) would probably not survive routine handling or impact driving. I have not run the numbers, but a basic simulation of handling would be to take a look at the pile as a simple unreinforced (horizontal) beam. The supports are either 1 or 2 choker cables used to lift the beam from a truck/barge/rail car. The load is the dead weight of the concrete.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[cntw1953]

I wouldn't use an unreinforced concrete pile whatsoever.
A bored pile with casing, or concrete filled pipe pile may have some chances, but does LPILE handle that?

 

[jgd2]

this concrete caisson is being designed for the sound wall. we had designed these earlier as reinforced concrete piles using LPILE analysis. the problem is with the embedment depth which came out around 22 feet even for 5 feet high wall. I was just trying to see if cutting out rebar and lowering the steel post size for the wall would lower the embedment depth...

 

[cntw1953]

Then you might have to increase the diameter significantly to engage more passive resistance, and lower the tension in the cassion. I doubt it is worthwhile to do so.