Wind loads on an irregular structure

[xp1]

I'm looking at sports facility type structure, it's about 400'x400' and steps in the center from an elevation of 155' to 185'. I've attached a picture of it's profile, which basically extends into the page for 400 feet (some reentrant corners though.)

We're designing the lateral system and I was just wondering, would it be okay to use the MWFRS Directional Procedure to estimate the lateral forces for some preliminary calculations? And when it comes to determining actual forces for use in design, can any of the procedures in the code be used or would this be considered too irregular a structure and thus require a wind tunnel study?



Structural Engineering Intern

 

[Stenbrook]

I would say that for the most part, most the buildings i work on are irregular shapes. With that being said, I have also never done a wind tunnel study and don't know of anyone who has. To the best of my knowledge, wind loading is not an exact science and thus using your engineering judgement to determine an appropriate wind load based on your building and using the wind code would be acceptable by most engineers. I typically use method 2 in the ASCE 7. Pretty straight forward design process. They used to design buildings for 20 psf lateral load and that was it and those buildings are still standing.... If you want to be most accurate though, then yes you would have to use a wind tunnel study.

 

[dcarr82775]

While not a box, I wouldn't say it is that irregular. I would just use ASCE7 and some engineering judgement.

 

[xp1]

Thanks for the responses, I guess as an intern I'm still missing some of the experience to make judgments comfortably but will try my best. Gonna talk to a superior now about how loads transfer into the diaphragm and then to braced frames, perhaps that will shed some light on these matters.

Structural Engineering Intern