ASCE 7-05 Wind

[cuels]

If I have a Type 4 Irregularity - Re-Entrant corner, the code states I can't use the Simplified Wind Load method because of the stipulation in 6.4.1.1. This method uses the zones labeled in Figure 6.2 and pressures in the following tables. However, I specifically remember my professor leading us through that procedure on an L-shaped building (re-entrant corner). Was that the wrong method to use or does one of the other procedures follow the same tables? I know that we had to design the drag strut and collector through the re-entrant corner, but everything else followed simplified method. We did break up the building to have two "a" zones on the outside corners. Any insight would be appreciated.

 

[woodman88]

If you read ASCE 7-05 section C6.2 on this, you will find a "L" shape building will be able to be designed with the Figs 6-6 to 6-17.

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.

 

[cuels]

Does that mean my professor was wrong in using the tables in Figure 6-2 to calculate the wind loads for this building? Both Methods 1 and 2 list that they are only to be used for buildings that are regular. Certainly we don't use the wind tunnel method for any building that has any irregularity...?

 

[woodman88]

Do not know what your building actually looks like. But if section 6.4.1.1 note 8 is not a problem than usually the building can be considered regular. I suggest you read Chapter C6 and form your own opinion for your structure.

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.

 

[cuels]

Maybe I am overthinking the code. Correct me if I am wrong, but the only description of a "regular-shaped building" is in 6.2, where it states that a regular-shaped building is one "having no unusual geometrical irregularity in the spatial form." However, when I am looking in the seismic area of the code it talks about structural irregularities in table 12.3-1. Am I considering a re-entrant corner an irregularity in seismic, where in wind it would be considered a regular-shaped building? Otherwise, 99% of the buildings out there are irregular in my mind for some reason or another.

 

[cuels]

Sorry, I initially said it was a Type 4 irregularity, but it is actually a Type 2 (L-shaped building).