Forces on Fences 2

[Logan82]

Hi,

My post concerns the forces on two types of fences:

Architectural Fences

What are the standards specifying the design forces to be applied on an architectural fence to block humans?

I did not find any, so I was thinking about using the forces for the guardrails according to the National Building Code of Canada. What do you think about this?

Chainlink fences

Are typical chainlink fences designed to act as a guardrail? Can you put them on top of a building to prevent humans from falling down?

 

[DoubleStud]

OSHA has a spec on how much load it needs to be able to resist.

https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.29

 

[Logan82]

If I am not mistaken, this OSHA link is for guardrails, but what about fences?

 

[WinelandV]

I think DoubleStud is saying, if you want the fence to act as a guardrail, then it needs to be designed for guardrail requirements.

As with most guarding, the hard part will likely be in how you attach the posts to the structure.

Please note that is a "v" (as in Violin) not a "y".

 

[JedClampett]

Are your architectural fences acting as a fall protection item? In other words, adjacent to a 30-inch drop? If that's the case, use the IBC (Chapter 16) or OSHA loadings.
As far as chain link, I doubt you could make the numbers work out, but it seems adequate for a guard.
[ul]
[li]On the one hand, they're much taller than guard.[/li]
[li]On the other, the post spans are longer.[/li]
[li]But maybe the fabric could resist some of the lateral forces in tension.[/li]
[/ul]
It depends who's reviewing this.

 

[Logan82]

Yes, the architectural fences are used as fall protection items, since they are adjacent to a 30 inch drop.

 

[Logan82]

The issue I see is that I have seen chain link fences on bridges instead of guardrails. But I have not seen any mention in the chain link standards that the chain link fences need to be designed to prevent fall protection. There is the CAN/CGSB-138 (available for free at

https://www.tpsgc-pwgsc.gc.ca/ongc-cgsb/publications/catalogue/index-eng.html)

that specifies some forces on chain link fences, but it does not specify that the chain link fences can be used for fall protection, and those forces are lower than what the National Building Code of Canada specifies for guardrails.

 

[milkshakelake]

You might be able to back-calculate the forces chain link fences can take from wind loads and see if it meets OSHA requirements of 200 plf or something:

https://chainlinkinfo.org/wp-content/uploads/2023/02/WLG-Final-2.12-23-ml.pdf

It's more to see the loads on the posts themselves. I personally wouldn't depend on the fabric for lateral loads, unless you have a source for that. But I have seen it done before on an engineered design. It's definitely possible.

You could just theoretically design the post for flexure per OSHA requirements and add intermediate rails (also designed this way) for the OSHA loads.

 

[CrabbyT]

As far as chainlink goes, it depends on the diameter and spacing of the fence posts.

Consider that if it can hold 2 MMA fighters, it's probably good enough for average pedestrian.

 

[xkcstructural]

Theres a good fence document that walks you thru design, or if your looking fjor code, ASCE has some guidance on signs, and posts and applying wind loads to those that could be useful or offer some guidance on how to approach the problem.