Pile Head Deflection For Shallow Pier Foundations
Pile Head Deflection For Shallow Pier Foundations
(OP)
Hello Eng-Tips,
I'm trying to design a flagpole foundation for deflection without doing soils testing. The concrete foundation is 1ft diameter, 3 to 6 ft deep, so I feel safe assuming it is rigid (i.e. Shallow Foundation).
The code says you can double the allowable lateral pressure if a half inch of deflection is permissible at the soil head, and I was wondering if anyone had experience with converting these values into an equivalent soil-spring value and then using that soil spring to determine expected worst-case deflection at varying depths.
I realize this is a bit on the "creative" side, but I would appreciate hearing from anyone who has been down this particular rabbit hole before.
I'm trying to design a flagpole foundation for deflection without doing soils testing. The concrete foundation is 1ft diameter, 3 to 6 ft deep, so I feel safe assuming it is rigid (i.e. Shallow Foundation).
The code says you can double the allowable lateral pressure if a half inch of deflection is permissible at the soil head, and I was wondering if anyone had experience with converting these values into an equivalent soil-spring value and then using that soil spring to determine expected worst-case deflection at varying depths.
I realize this is a bit on the "creative" side, but I would appreciate hearing from anyone who has been down this particular rabbit hole before.






RE: Pile Head Deflection For Shallow Pier Foundations
As an example: http://www.colonialflag.com/external-35x5x-125-res... (I have no interest whatsoever with this company or its website)
RE: Pile Head Deflection For Shallow Pier Foundations
I actually don't know anything about the site.
RE: Pile Head Deflection For Shallow Pier Foundations
Soil info here: http://websoilsurvey.sc.egov.usda.gov/App/WebSoilS...
If I'm permitting 1/2 deflection at the pier top (by doubling allowable pressures), then there is a 1/2" deflection at the pile top.
If I'm not permitting that deflection (by not doubling the allowable pressures), I'll assume that there is no deflection at the pier top (which is good enough for my needs in this application).
RE: Pile Head Deflection For Shallow Pier Foundations
RE: Pile Head Deflection For Shallow Pier Foundations
Also, if someone wants to figure out how to install a ground screw literally coated with Teflon (or equivalent), the PV industry in Canada will probably thank you (read give you money).