As-built piles stresses

[SteelPE]

Is there a standard practice to allow for an overstress in a pile in the as-built state. I have a bunch of wooden piles that are out of tolerance. Upon analysis, some of the piles are overstressed by less than 10%. I have been told that it is common to allow this tolerance for a pile group in the as built condition. I am wondering if this is common or not.

 

[Ron]

How good are the assumptions that led you to the overstress conclusion? Do you have load test data or just driving data. Depending on the type of soil conditions, piles can gain load resistance with time, particularly in marls and similar soils.

 

[BAretired]

Are the piles overstressed in combined axial and bending capacity or in soil resistance?

BA

 

[SteelPE]

In going through the numbers it was brought to my attention that according to the building code a 10% overstress in the as-built pile locations is acceptable. This building code is a jurisdiction version of IBC 2003. A similar number can be seen in IBC 2009 1810.3.1.3 but the jurisdiction version is a little more specific when it comes to field mislocation.

 

[rscassar]

The piling code I use allows 75mm tolerance. When designing a pile cap I make my designs based on the assumed pile location plus the adverse effect of a pile being out of position 75mm.

You shouldn't have to tell the client the piles are overstressed if they have been driven within tolerance.