Base plate design 1

[yjung]

Hi,

I am designing many baseplates for light poles.

I have a question on how to find out the plate thickness and size with applied moment, torsion, axial load and shear.

Most of examples on books of baseplate calc's don't have moment and torsion, but only an axial load.

Do you know where to look to find a good example of finding a plate thickness and size with anchor bolt?

I have an example of calc's. It assumed to use a tension force on the end of a assumed triangle shape of the plate and find moment and find "t" and "d". I do not know this is the right way.

please help.

 

[ajose]

Hi there,
I got some reference but i guess not available there:

"Proyectos estructurales de acero" - PHD. Eng. Maria Graciela Fratelli (from a Venezuela univertsity)

"Manual de proyectos de estructuras de acero" Volumen II Diseño de miembros y uniones - SIDOR (a Venezuela steel factory)


But the base:
For base plate poles with 4 anchor bolts you can do something like this:

Triangular distribution for concrete compresion.
Tension on the place of the achor bolts.
Maximum bearing compresion on concrete 0,3·fc
Solve the system for forces equilibrium.
ΣM=0 ΣF=0

Once you get the solution you have to:
Verify the asumptions.
Check the thickness based on maximun stress 0,75·fy, both sides compresion and tensio have to be check.

The other way it's more or less the same but strain compatibility.

 

[ajose]

Hi there,

There is some reference on the subject on the forum (in this site),

Rigid base plate design

 

[CanyonRat]

I have a very good example (my own) but it would probably be easier to fax it to you than try to explain.

Email me off broadband at miked<at>horrocks<dot>com

That's miked@horrocks.com in case the web site hides the email addresses.

MikeD