Outdoor Baggage Conveyor Wind Uplift?

[structuralgh]

I am working on an outdoor sloped conveyor that is the typical conveyor you would see when you go to baggage claim at an airport. I is in the shape of an elongated oval. It is 90' long and 17' wide and 5'high. It sits at grade level.
I have used the solid sign provisions of ASCE 7-05 for the lateral loading and calculated a 40PSF load, with 140mph, exp C type III (airport- essential structure needed in an emergency), importance factor 1.15.

There must be an uplift component to this structure, what section of the ASCE 7-05 would you use?

Thank you for your help.

 

[TXStructural]

ASCE 7 will not predict loading on complex shapes. The wind provisions are notional loads, which cannot be generalized to cases like this. An oddly shaped piece of equipment requires a fluid flow model to predict the forces and flows.

Additionally, since the equipment appears to be located under a structure, ASCE 7 cannot be used, since the flow of wind will have been disrupted.
Wind codes determine wind speed values based on a certain profile (higher wind as altitude increases, until you get beyond the effect of drag across the land surface.) They depend on a relatively smooth flow of wind. Your structure may result in significant increase in local wind across your equipment.

I would start by calculating leeward and windward pressures on a rectangular box of the same rough dimensions, and look at overturning forces, based on anchor locations. For C&C, use the largest corner/edge value for the entire surface

Component wind forces could be significant, such as the wind pulling up on the conveyor fins. Since you are considering hurricane winds (140), consider that there will be a prolonged cyclic load on loosely attached parts and fatigue will be a major concern for thin metal parts. (Have you ever seen sheet metal in the aftermath of a hurricane?)