Wind Load in Conical Structure (Stockpile)

[carlosbenavides]

Hi, does anyone know any reference that give you wind pressure coefficients for conical structures with approximately 40º slope?
The structure is a stockpile, and I reviewed many codes of Wind Load, without success.
Thanks in advance.

 

[Ron]

I'm curious...why would you analyze a stockpile for wind load, assuming its material consists of loose particles of some sort? It won't act as a structure.

 

[carlosbenavides]

Hi Ron,
I must say Stockpile cover, like the structure showed in attachment.

 

[racookpe1978]

OK. You've got little problem here. That's a very low, very slightly sloped but light weight cone drawn there.

If you took an apparently very conservative approach and assumed it was a simple round tank of equal height and equal outside diameter, your wind load - sideways! - would be more than what would occur in the real world. So, your shear force on the bottom mounts would be exaggerated, and the downwind side (downwards force) and upwind side (upwards force) of the simulated cylinder trying to tip over would be greater than what would really occur.

But, by calculating things that way you completely miss any lifting force as the wind accelerated over the top of the slightly sloping cone. I don't have the background to calculate it (maybe the aerodynamic forum??) but a section view of that lightweight looks much more like a wing-shape than a cylinder. You'll be getting less shear resistance (which creates a tipping force) but will need to worry about the Bernoulli lifting force as the wind goes over top of the cover. .

 

[Ron]

Carlos...thanks for the sketch. Makes sense now.

I'm not sure where you're located, but hopefully your building code has a provision for domed structures. If so, that is the approach I would take, using the coefficients for a dome rising from the ground at or near the angles of the structure. ASCE 7 in the US has such a provision.

The actual loading might be slightly different, so be conservative in the application of your coefficients and your projected areas.