WInd Loads for h < 60 ft

[Murali27]

Dear everyone,

I have a building right now with L = 45', B = 30' & H = 55 ft.

Can i use the procedure stated in asce 7 for h < 60ft?.
Am i missing something.....

If the structure is flexible (where h<60 ft), how to include gust factor.

Thanks for your info on this.

 

[ajh1]

Your eave height exceeds the least horizontal dimension so you do not qualify for the low-rise provisions (definition in 6.2). That means you fall under either 6.5.12.2.1 or 6.5.12.2.3 (not 6.5.12.2.2). You are permitted to use the normal wind provisions, rather than the low-rise provisions, at any time but not vice versa. References are to ASCE7-02.

 

[Murali27]

Thanks ajh1

If i am right, say this is applicable only in the direction
perpendicular to the least lateral dimension (which is less than eave's height). i.e

B = 30 ft, L = 80 ft & H = 55 ft.

In the direction perpendicular to "L" = 6.5.12.2.1 or 6.5.12.2.3

In the direction perpendicular to "B" = 6.5.12.2.2 or 6.5.12.2.3

The class 6.5.12.2.3 to be used irrespective of eave
height only if structure is flexible.

Thanks in advance

 

[ajh1]

The definition does not distinguish between dimension parallel to wind and dimension perpendicular to wind, it simply says least horizontal dimension. Realistically I doubt there is that much difference in actual loads between 6.5.12.2.1 and 6.5.12.2.2. I would probably use 6.5.12.2.1 for both directions regardless of the applicability of 6.5.12.2.2. Simpler, easier for the code guy to follow, etc.

 

[Murali27]

Thanks ajh1