Pile design for Direct buried pole

[saos]

Hi All,
I'm a civil engineering graduate and stuck with this design.
I need to design a pile foundation for a transmission pole. But this is a direct buried pole and does not use any steel reinforcement. I have used BH pile software (which uses the Brinch-Hansen method)and determine the length of the pile. My design moment is 110kNm and the shear force is 21 kN. (at ground level). Therefore, I designed this pile foundation with 2m depth and 0.9m dia and it gives me max moment capacity of 800kNm and max shear of 891kN.

But my problem is, with this method, I can go even a 0.1m diameter pile and pass the design requirement of 110kNm which totally does not make any sense because my pole diameter is 460mm. Can I please know any different methods and pole-to-pile edge distance requirements?
Any reference document or standard on this matter is really appreciated.

Thanks.

 

[geotechguy1]

Rule of thumb design starting point is minimum 10% of pole length + some arbitrary amount which varies by area (often 0.6m).

Eg:

https://www.rd.usda.gov/sites/default/files/UEP_Bulletin_1724E-200.pdf

Could also try get a copy of EPRI Report EL-6309