huangyhg

foundation for minimal gravity load and significant moment
i am needing to design a foundation to support a cantilevered steel column that has very little gravity load and lots of overturning. it is 12' tall and has a lateral load of 1,500lbs carried at the top only. i am not restrained at grade. how do i model this? i would really like to design a reinforced concrete shaft that can just be drilled into the ground and filled with a reinforcing cage and concrete. any tips or references that anybody can point me to? i'm thinking that there has got be something out there for flagpole or billboard foundation design.
thanks.

there is a book titled, "engineering sign structures" that covers this.
it may be more cost effective to use a large concrete block as oppposed to a drilled shaft since there is not a lot of moment here. the block would have to be sized to provide enough weight to resist overturning. it's a few very simple hand calcs to complete the design so trying to model this will take much longer in my opinion.
try the attached nomograph.

try winpost by archon engineering ( about $30.
"winpost will help you analyze your embedded posts. the program will perform a stress analysis on the posts and determine how deep the posts must be embedded into the ground. the program has a simple section property calculator, soil database and wind load calculator. you also have the option to enter a single lateral load on the posts as well as an axial bearing load."
good luck
i've always used enercalc. you can get a fully working copy of version 5.8 here:
thanks everybody for your help!!!

you may want to take a look at the following:
"drilled pier foundations" by woodward, gardner and greer, mcgraw-hill, 1972
also, the paper "analysis and design of laterally loaded piles and caisson in a layered soil system" by naik and peyrot, asce
both have very good examples.

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