Wind load for Small room inside a huge structure

[Alaazaki]

I have a a small room inside a huge structure (factory) but not connected to any part of the big structure I don't know if I should take in my consideration the effect of wind load or not because the big structure is already designed with wind load

 

[MotorCity]

If its not connected to the larger structure or located near an opening where it could be exposed to wind (like a roll up door), then you don't need to design it for wind. However, there is a minimum lateral load that you can apply, I don't have my code right now but I think its 5 or 10 psf.

 

[JAE]

ASCE 7-05 has a provision for interior partition wind loads of 5 psf. Other than that - use the seismic demand or, really, anything higher than that if you so choose.

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[racookpe1978]

If the small building is EVER going to be "funneled" wind by the large building doorways or truck accesses or railroad doors or by wind getting channeled by the walls and corners between two or more adjacent large buildings, then it actually may need more analysis than the simple stand-alone big building.

If not, the large building will shield the small building if it is inside the big building.

 

[haynewp]

We had this come up before where it was a PEMB going inside a much larger facility. The PEMB engineers refused to design the interior building for 5 psf because they felt the larger building could be removed at a later time, though there was no owner intention to ever do that. I think they somehow related it to the shielding provisions in ASCE 7 but I doubt that was ever considered as part of the intent of those provisions.

 

[Once20036]

I've been thinking about this one recently as well.
As JAE indicated, there's the code provision for 5 psf horizontal load on interior partitions.
When you look at the equations for MWFRS and C&C Wind loads, there's a component for interior pressure effects, GCPi.
This load is greater than 5psf (5.7psf for my recent calcs with GCPi = +/- 0.18) but ASCE 7-16 is going to add a category for partially enclosed buildings with GCPi = +/- 0.55 (17.5 psf).

How is it that we design our C&C for an internal pressure of 5.7 (soon to be 17.5), but our interior walls for an internal pressure of 5psf?

 

[MotorCity]

In my opinion, if the larger building is modified such that wind forces are now on the smaller building, the engineer modifying the larger building is also responsible for the effects on the smaller building. The original engineer of the smaller building cannot possibly be expected to account for all future renovations. If you modify it, you own it.

 

[Teguci]

From a code perspective, these are not two different buildings. It's one building on one lot (good luck with fire separation otherwise). They might have separate structures, but so do lots of things. As MotorCity said, anyone modifying "the" building is taking responsibility for what's left. As a sidenote, any modifications that happen to the larger structure due to this smaller structure are now the new designers (foundation issues come to mind).

 

[BAretired]

I would design the small building for more than 5 psf wind load because it is much easier to do it now than some time in the future. 20 psf wind load seems reasonable.

BA

 

[Stenbrook]

@ Once20036, ASCE 7 has had partially enclosed GCPi in there for a while now of +/-0.55.

The minimum interior pressure as I have always known it was 5 psf. It is stated that way in the code. But that is exactly what it is named, a minimum. It is up to the engineer to decide what an appropriate loading is for their conditions, but it must be at least 5 psf.

 

[BSVBD]

I've designed interior walls to resist the same pressure as exterior walls in PEMB's with multiple OH doors on each opposing sidewalls. - similar to racookpe's reply

I haven't dealt with "tunneling" before. Perhaps i under-designed them?

 

[BAretired]

BSVBD,

The partition between stalls of a carwash is a good example of that.

BA

 

[sponton]

The 5psf wind load pressure it's actually to be treated as a live load, I only mention this because it may be affected with the load combinations.

1607 LIVE LOADS
1607.13 Interior walls and partitions. Interior walls and partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength to resist the loads to which they are subjected but not less than a horizontal load of 5 psf (0.240 kN/m2).

 

[BSVBD]

I've been using 5 psf as a standard without looking it up.

I see:
5 psf in 1607.13 under LIVE LOADS in IBC 2009
5 psf in 1607.14 under LIVE LOADS in IBC 2012 & 2015
5 psf in 13.5.8.1.3 for seismic in ASCE 7-05.

I don't see this provision in ASCE 7-05 for wind. Can anyone pin-point it for me?

Thank you!

 

[AnimusVox]

If I were designing this smaller building inside the hangar, I would design the lateral force to the 5 psf minimum, although I would increase that if it was adjacent or was exposed to exterior wind loads. (Depending on how windy of an area you're talking about and alignment with the hangar doors)

I would consider designing the walls for a partially enclosed condition if the building meets the criteria to being classified as such.

 

[BAretired]

How much are you saving by designing to such a low wind load? That would be the first thing I would consider in such circumstances. In all probability, it costs virtually no more to design the smaller building to resist full wind load.

BA