Wind load enclosure type for steel building

[h-badawy]

Dear Experts,

I have a shade with the dimensions of (46X120)m ,The 2 walls at the short side of the shade have openings at the bottom with about 1.6 m height, and the other two long sides are full opened (see below photo) There is a big difference between me and the contractor(vendor) in the the approach of the types of building enclosure for wind load and we stop in this point because the significant effect of this point on the foundation and design elements.
Contractor approach:
He referred to ASCE_7-16. He saw that Enclosed, Partially Enclosed and Partially open buildings are not applicable. Accordingly, Partial open building is the applicable case. For Partial open building case, the internal pressure is ±0.18 (very low) which is the case of enclosed building. Hence he applied the coefficients of the enclosed case to calculate the wind pressure on walls and roof.
my approach:
I should consider freestanding for the short side each side and open building in the long which is the worst case can be happened and i think in that case I will cover all critical cases that might be happened for wind load.

please advise

Thank you

 

[ProgrammingPE]

The contractor's approach appears to be correct to me. The building is not Enclosed, Partially Enclosed, or Open, so GCpi should be ±0.18 for Partially Open. Using a value other than this would require one of the other Enclosure Classifications to be met, and I don't see how that is possible.

Structural Central

http://www.structuralcentral.com

http://www.youtube.com/channel/UCOj2mXXf3ZbZtgxTc6BtkGg

 

[h-badawy]

my concern for this shade is two points
point number one the distance between the two short sides is very long and may be each side can be exposed to windward and leeward same like the freestanding sign or fence so in that case the value of Cf which is two much bigger than the Cpi value from Partially open .
point number two, for the long side it is very clearly that the building is totally opened and the value of CN on the roof is more than CPi value on the roof from Partially open.
and as per ASCE 7-10 we should study each wall/roof that receives positive external pressure as a separate case.

Thank you