Chicago Building Code - Wind Loads - ASD?

[P1ENG]

I have to check a canopy going to Chicago. It is less than 200' so the lateral MWFRS wind pressure from column A is 20 psf. It is an open structure, so the uplift is 100% of that value [20 psf]. It is basically just a parapet, so the lateral force is 200% of that value [40 psf]. This is MUCH greater than if I calculated the wind pressures per ASCE 7. So, the question is, are these the values that replace net pressures of ASCE 7 (1.0W ASCE 7-05; 0.6W ASCE 7-10}, effectively making them my ASD wind pressures? They don't get factored somehow? I am using the 14th edition SCM to check my steel, not the super old whatever is referenced. It would take too much time to "downgrade" my calculation template for the occasional Chicago project. So annoying; if ASCE 7 is good enough for CA (high seismic), FL (high wind), and Minnesota (high snow), it should be good enough for Chicago which is moderate in all of these!

Juston Fluckey, SE, PE, AWS CWI
Engineering Consultant

 

[DaveAtkins]

I think you need to follow the Chicago Building Code, not ASCE 7. But I bet the question has been asked--maybe check the Chicago Department of Buildings website for FAQ's?

DaveAtkins

 

[P1ENG]

Dave thanks. I'm not using ASCE 7, just trying to understand if the wind pressures that the Chicago building code can replace the values of my ASCE 7 pressures. Eg. pE=pF=20 psf
I want to hard-code these values into my ASCE 7 variables in my calculation. Their website is exhausting, but I am actively searching for the answer to my own question.

Juston Fluckey, SE, PE, AWS CWI
Engineering Consultant

 

[MrHershey]

They don't really clarify but I'd tend to take CBC wind at allowable level. Mostly because the concept of wind at ultimate level is a recent idea and the CBC still references very old standards. It still references ACI 318-83 for concrete, ACI 530-92 for masonry, the '91 NDS for wood, and 1989 ASD/1986 LRFD for steel. Technically their lateral loads chapter still even allows the old 1/3rd stress increase...