Filled vs. Hollow Pile

[HollyM]

I am looking to compare a foam filled thin walled cylinder section, with a hollow thicker walled cylinder. The client originally specified a thinner walled pile with a foam core, we would like to present a hollow pile with a thicken wall as an alternative. All parties are in an agreement the additional thickness will provide the addition support during impact and bolting, but they would like some technical support.

What equation(s) would support this? Would you compare the EI value of the two piles?

Thank you,
Holly

 

[cessna98j]

Foam filled piles?? I can't imagine foam would add much structural strength to the pile as a composite section - what kind of foam are we talking about?

There is a section in AISC 13th edition which addresses composite properties of concrete filled steel piles. I imagine you could modify the equations based on the strength of the material you're using in place of concrete. This is in sections I2 & I3 of the AISC 13th general provisions.