What is the purpose of the building? There are standards tables for the loading depdending on uses. From there, the standards should be able to to help. What are the soil bearing capacities? What kind of earthwork will need to be done to prepare the site?
A question like this depends on many variables, and is difficult to answer online. But more important, it is in violation of Registration laws to answer this type of question online. It is like asking a doctor to diagnose an illness online.
Really, swine? What if the wind upift exceeds the dead load of the pile? I don't think this forum is to deprive professional engineers of their fees. I always give answers in line with that philosophy. Maybe you should quit your day job and do nothing but give out free answers on this Forum.
No one can give even half-way legitimate answers via only internet communications, if this were possible we would all be deprived of our fee, regardless of philosophy.
As to your question, the length of the pile must be long enough to prevent uplift. The only reason I wrote in is because the constant legal reminders, by yourself and many others, get in the way of communication on legitimate posts. Your response didn't add anything.
You will want to go to ASAE EP486 DEC92 Post and Pole Foundation Design to have your poles, footings, and piers designed.
Before doing that, you may want to go over ASAE EP282.1 DEC94 to cover Diaphram Design of Metal-Clad, Post-Frame Rectangular Buildings, and ASAE EP2885 EP 288.5 DEC92 Agricultural Building Snow and WInd Loads.
Also note, these standards may have been updated since my current copy here at home is 1995. I doubt much has changed, they tend only to add new areas rather than revise old standards.
Swine, I really didn't want to add anything to this post. My intent was to recommend hiring a local engineer. This forum works best when one structural engineer is asking another for advice, such as how to handle a confusing Code issue.
If I had a legal question, I would hire a lawyer, not troll for free advice in a lawyer forum.
