embedded pier design

[sonnyson]

I need to support a solar panel array (120 SF) on an embedded concrete pier. Wind loads are 100 mph, exp B. I want to use procedure for signs in ASCE 7-05.I want to use a 36" diameter pier embedded into 11-65 soil about 9 feet to keep it above water. The height of the pole above grade is 24'. Typically, the allowable lateral soli bearing constant is 100 psf/ft. In this poor soil, I would expect it to be much smaller. Is there any way to improve it with compacted gravel around the pier? Also thought of adding a square base footing at the bottom (4' x 4')to help the whole system with bearing and to afford more lateral restraint.

Any thoughts?

 

[cap4000]

I would use gravel and see the link below for your analysis.
Good luck with your 24 foot high pole. Hope this helps.

http://bse.wisc.edu/bohnhoff/Publications/Copyrighted/EP486_1.pdf

 

[GeoPaveTraffic]

I would have your geotechnical engineer use a program such as LPile to analize the foundation.