Wind Load Per Euro Code

[antiwheel]

Hi,
I have a question about wind load determination of stairtower based on Euro code.

Euro code 1-4, 7.11, Lattice structure.

is a 5 story, 3m(width)x3m(depth)x15(hight) with X bracing a lattice structure?

Thanks

 

[Ussuri]

If your structure is braced in all bays and the bracing system is fully triangulated across the full height of the structure, and the bracing is your only lateral load resisting system then yes.

However, the fact you have mentioned 'stairs' would make me suggest caution. The loading on lattice structures is predominately due to air flow around the members. You do not have any significant projected areas. The lattice is mostly 'air' and not solid on any elevation.

You stairs may actually include a significant projected area which will attract additional loading so assessing it as a pure lattice may end up being un-conservative.

 

[antiwheel]

Thanks!
I will not consider it a lattice structure.

 

[csd72]

antiwheel,

I would check both and take the worst case.

I have no idea what ussuri was on about, but lattice structures usually have a higher wind load per unit area than a solid structure - of course the solid structure has more area to contribute.

 

[Ussuri]

what I was angling at was the area of the stairs is probably much larger in relation to the area of the lattice work.

As I understand it the forces on lattice type structures are as a result of the flow past/around the elements and as such are typically frictional drag forces. While the loading may be higher, the area you are taking it over is less.

As opposed to a wind pressure taken over a larger area (form drag).

 

[csd72]

Sorry ussuri, I understand now, but I would take the stairs as the same wind load as the lattice, the members exposed to the wind will be similar.

 

[antiwheel]

thanks guys
I check both of them. and it's more conservative to be considered as a fully closed structure. it gives me a margin around 10% compared to consider the wind pressure individually.

anyone of you familiar with Greece code? what is the definition of wind speed in Greece code? do you have a wind map of Greece that can share?