Barrel Vaulted Roof - Wind

[slickdeals]

Folks,
I was asked to calculate the wind pressures for a double barrel vaulted roof for a aircraft hangar.

ASCE does not have anything for such situations, the closest there is is a multispan gable roof or a sawtooth roof.

Has anyone calculated roof pressures for such buildings? Ideas?

 

[msquared48]

Nothing in SEAW Rapid Solutions manual either. Hmmm...

Looks like the closest is Fig-13 in ASCE7, or an adaptation of the arch section to a Mansard type roof as shown in the lower left of Figure 6-6.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[msquared48]

I checked an old Plywood Diaphragm Construction manual from the APA and all they did was use the projected area and apply the wind to get the diaphragm load, but that tells nothing about the uplift.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[slickdeals]

I was also looking at Figure 6-8 on ASCE that talks about arched roofs (either springing from the ground or an elevated structure).

However, for the perimeter (which is not defined), the wind pressures are based on ASCE Figures for Gable/Hip roofs with the theta being the spring-line slope.

 

[Ron]

slickdeals...I've done probably a dozen or so of these and have used the ASCE arched roof coefficients, considering the start of the arch to be the same as the "springing from ground".

 

[slickdeals]

Ron, good to know.

My arched roof starts at 36' above ground. The rise is 16' and span is 103'.

I am using the requirements for "Roof on an elevated structure" and determining the C&C pressures. For C&C, the Footnote 4 requires the use of a pressure corresponding to hip/gable roofs for the perimeter and 0.87 * other factors.

Do you know what defines the perimeter? Is it similar to "a" dimension in other tables?