Monopole Retrofit (RisaTower)
Monopole Retrofit (RisaTower)
(OP)
I've got a new one on my plate. I'm trying to work out the best way to design a monopole with channels attached to the outside edge. I have RisaTower but can't seem to find any function for this design. I'm thinking of splitting the tower/channels into 5 ft sections. Using the bending moment and shear diagrams from RisaTower and then creating a builtup section in Enercalc that will handle the shear and moment.
The only problem is i'm not sure how to finish out this calculation. Right now the Enercalc only gives Section modulus and moment of intertia. Does anyone know a calc that can tie this together?
The only problem is i'm not sure how to finish out this calculation. Right now the Enercalc only gives Section modulus and moment of intertia. Does anyone know a calc that can tie this together?





RE: Monopole Retrofit (RisaTower)
RE: Monopole Retrofit (RisaTower)
RISATower will give you the ability to do generic code checks (F standard mainly) based on the properties (Ix, Iy, A, QaQs, Sx, Sy, et cetera) that you enter for the shape. You would have to use another program (or hand calcs) to come up with those values. Enercalc could work, RISASection would work, but there are a number of others as well.
Let me know if you're using the TIA G standard. If so, then I'd have to check to see exactly how the code checks on an arbitrary sections are done.
Josh
RE: Monopole Retrofit (RisaTower)
Do you know of a hand calc for QaQs?
RE: Monopole Retrofit (RisaTower)
RE: Monopole Retrofit (RisaTower)
I looked up what we do for the design of arbitrary sections to LRFD based design (Rev G):
phi*Mn = 0.9 * 1.5 * fy * S
Where S is the smaller of S_top and S_bot, for each bending axis.
The next release will revise this slightly to be:
phi*Mn = 0.9 * 1.5 * fy * S * QaQs