Estimating a Wind Load

[ReverenceEng]

So I have been contracted to put a sign on top of a stadium. We've done these before, but normally we have wind loads from a wind study performed when the stadium was built or when there was a major renovation.

It's basically going atop concrete bleachers, and I'm not sure what section of 7-10 I could use to establish a wind load to satisfy the plan checker. It's kind of an open building, and it's kind of "rooftop", and it's kind of an appurtenance, but it's definitely over 60 ft. sigh. I really just want to go with an extra conservative wind load and call "that" justification, bit pretty sure that won't fly.

Anyone ever been in a dilemma like this or have any recommendation?

 

[JAE]

Without a wind tunnel test you would be stuck with finding the closest ASCE 7-10 wind condition to apply. To me it sort of looks like a parapet.

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[RobertHale]

You could get an envelope of forces/pressures using the sign provisions and the parapet provisions. I think I would look at three cases, (1) an unobstructed sign at the actual elevation (2) a sign treating the stadium as a hill and using the topographic effects and Kzt, and (3) a parapet on top of a building. You would have to make some rational assumptions for the stadium as a hill and the stadium as an enclosed building.

Robert Hale, PE

 

[JStructsteel]

if you have done them before, can you look at those and interpolate a rational wind speed?

 

[gravityandinertia]

You could contact an analysis company, have a CFD analysis of the sign for the proper wind speed. My company does this sort of work occasionally. It will depend entirely on your budget, or your clients budget if you can go back and ask them to pay for it. Also whether or not the municipality will accept it.