Lateral Structural Stiffness of Pile

[X-Wing]

May I know how to compute the lateral stiffness of a pile, I've read on some references and also from here that it is usually 40 kips/in (about 70,000 kN/m/pile), but I think this is also dependent on the material and diameter/dimensions of the pile.

Thanks!

Very Truly Yours,

- andru18

 

[KootK]

It definitely depends the material and the cross sectional properties. It also depends on the stiffness of the surrounding soil and, in the case of concrete, the degree of cracking. If you google the P-y method, you'll be off to the races.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[MotorCity]

In lieu of using fancy software and obtaining a solution that considers the soil contribution, you could calculate an upper bound (conservative) solution by considering the pile only.

Just apply a load and calculate the deflection, then use to determine the stiffness. The pile is most likely much stiffer than the surrounding soil. Apply the load to the tip of the pile as if it were a cantilever column. Take the length of the cantilever as the distance from top of pile to a point where the moment in the pile is maximum (typically this occurs at a depth of 4 to 7 pile diameters below ground).

That should get you in the ball park.