ASCE 7 C&C 1

[SteelPE]

I am trying to figure out exactly when to apply the zone 5 C&C pressures to my wall in accordance with ASCE 7. I have a wall that turns 45 degrees. Do I apply zone 5 pressures here or would you still use zone 4 pressures? What angle do you begin to use the zone 5 pressures?

 

[slickdeals]

I would say Zone 5, partly based on reasoning below and partly because you might find a conservative plans reviewer.
_/
Wind to North would cause Zone 5 in the "underscore" wall
Wind to West would cause Zone 5 in the "slash" wall

 

[woodman88]

I agree with slickdeals.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[charliealphabravo]

The analytical method was developed to deal with "Regular Shaped Buildings". This term is not very helpful so thankfully you have the definitions. ASCE 7 defines "Regular Shaped" as "having no unusual geometrical irregularity in spatial form". Unfortunately this definition is equally useless.

What they are trying to say, without actually saying it because that would make the standard worthless, is that the models used to develop ASCE 7 were rectangular. You have to use engineering judgment to use the standard in the real world if you don't wan't to tell your client that you need a wind tunnel for every project.

In other words, it is probably best to lean to the safe side and use the higher pressure coefficient.

Just sayin...

 

[Ron]

Under ASCE 7, load application is normal to the surface. Since the wind can blow with an orientation of any of the 360 degrees available, you will always have the potential of wind blowing normal to some orientation, no matter how oblique. Use Zone 5.