Universal Bearing Pile design

[nj86]

Hi,

I am trying to design some universal bearing piles which will be around 1m below ground level and approx 5m long.

I was wondering what the procedure is to designing them with regard to British Standards?

Do i just treat it as a UC section and analyse it the same way?

The concept is that a ground beam sits on top of the bearing pile and on top of this is an upstand.

Hope you can help

Thanks!

 

[ishvaaag]

A pile is a pile in whatever the material ... I mean, you need to asecertain what kind of loadings will be imparted to them, particularly if will be subject to any lateral displacement etc. Then the soil will help us to decide how to consider the transfer of forces to it, tip, friction or both. Buckling of (embedded) piles uses not to be of much concern -since confined at any direction can't progress, and when separating from the installation axis it is normally the soil driving the pile to its limit strength- and then you apply more than anything a pure strength of materials approach on the section. Plastic limits of whatever stress origin (flexure, shear, axial) need be respected. Connection to the pilecap needs to be considered (pin, fixed). Also, the books give top structural design forces to be attained by the piles. And do not forget an excess section in accord to the expected life expectancy out of corrossion.

 

[ishvaaag]

Corrossion rate

http://www.ice.org.uk/downloads//BS-Acceleratedlwc.pdf

 

[ishvaaag]

Corrossion rate

http://www.ice.org.uk/downloads//BS-Acceleratedlwc.pdf

And since my wording about plastic limit states sounds extremely optimistic and close to one limit states design (that may be warranted for some hypotheses), pile design is usually made at service level, and be sure the limit stresses allowed for the particular cases for axial (or longitudinal stresses) are respected. These are well below one LRFD estimate, even after retiring the safety factor.