long span curved roof + wind upflift: Your experience? 2

[IJR]

Pals

ASCE code says there will be a serious uplift on a large part of curved roofs(wind pressure coeffs of about 0.8 to 0.9).

These roofs are usually lightly clad and uplift is usually there.

What is your experience? Simply to share with us. What are we to watch out for?

respects IJR

 

[dik]

What is your roof construction? curved girders, straight purlins/OWSJ, segmented deck/rolled curved deck? All should be appropriately designed (lateral support) and fastened...
also, the type of roofing over the deck(?)?

Dik

 

[IJR]

Thanks dik

it is curved girders and the roof is clad with just glass

respects
ijr

 

[JAE]

ASCE 7 has design criteria for arched roofs. I don't know if this is what you are looking for or not.

 

[dik]

Purlin members are likely laterally unsupported due to flexible fasteners for glazing; the Lu may be the full purlin length. The curved girders can be laterally supported by the purlins. I'd be a bit concerned about the flexible attachment of the glazing with rain and wind loads; the curve can act as an 'airfoil' and produce significant uplift forces. One of the old NBC of Canada had a publication with various loadings. These were predicated on earlier loadings prepared by the University of Bern in Switzerland. The publication has whiskers, but is still applicable for some odd loading cases.

Dik

 

[IJR]

Thanks dik

simply put great input