handrail loads

[exael]

Hi engineers,

the required load for handrail abour forum is 50 lb/ft or a 200 lb concentrated load, in what bibliograhy I can found information?, is life or dead load?

 

[bridgebuster]

it's live load. It's specified in ASCE 7, IBC, AASHTO, etc.

 

[Luceid]

The ASCE 7-16 reference is 4.5: LOADS ON HANDRAIL, GUARDRAIL, GRAB BAR, AND VEHICLE BARRIER SYSTEMS, AND ON FIXED LADDERS.

 

[exael]

On the stairs there are two handrails on both sides, it is enough to load on one of them horizontally, or is it necessary to load both handrails?

 

[rb1957]

i'd go with both, but you might be able to say that by inspection the LH one is more critical.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[exael]

What is the maximum deformation in the handrail, L/?

 

[driftLimiter]

All the handrails have to meet the requirements. Loading one side vs the other side is really irrelevant to the handrails and its connections. If there is some loading you are concerned about the in the elements supporting the handrails you might want to consider the loading on each of them simultaneously or perhaps just one side. Which ever causes the worst effect.

There is no strict limit to deflection on these but if you have a massively flexible guard rail its wont be perceived as being strong enough. Human comfort is needed for something like a guard rail.

 

[Aesur]

The loads are live loads and are applied in any direction, therefore it's not just horizontal, you need to also check as if it's a vertical load. Typically you check for the worst case of 50 plf and 200 lbs, this is why manytimes vertical supports are spaced at 4'-0" o.c. such that 50 plf loading is equivalent to the 200 lb point load. Deflection is a tough one for these, I'm not aware of anything other than the normal deflections for say a wall. There may be some OSHA requirements that it rebound to its original installed position. Make sure to review the codes as the loading is applied at a certain height. Many times I find that the controlling elements are the vertical supports and the connections.

 

[exael]

Ok, thanks. I am reviewing the load considerations because on sap2000 model, when to load the handrail with a horizontal load of 50plf the beam that supports the steps increases stress and deformation, and when to load both handrail this increases more.

 

[JStephen]

The codes don't specify a lot of detail on the loading.
I would assume that vertical handrail loads and vertical live loads on the stairway itself are not combined, but I'm not aware of anything that says that.
On whether both rails are loaded- I would think that would depend on how wide the stairway is, as to whether enough people could congregate to load both railings (or whether that's considered likely, even if possible.)
OSHA has limits on stairway deflection in some cases, but they are large, and for limiting deflection on cable-type guardrails. That may be in the "construction" standards rather than the General Industry standards. (Neither would normally apply to residences).
I was thinking there was a maximum 4" gap provision in those midrails for rails accessible to kids.

 

[JLNJ]

I would say by inspection that the fastening to the treads is critical.

As Aesur says, the load can be in any direction. It looks like inward toward the stair centerline will be the worst case for the fasteners in your photo.

 

[Luceid]

ChatGPT again?

 

[SWComposites]

Do people really use FEMs for handrail analysis??

I would be worried about that center post connection to the pointy end of the tread.

And would be worried about the left side straight railing that doesn’t seem to have a connection to the wall, and with the column base bolts not alined with the sideways moment.

 

[Stanley Shum]

Yes, response by ChatGPT.

 

[Luceid]

Please stop, thanks! Everyone is capable of searching chatGPT, that isn’t what this forum is for.

 

[dik]

JLNJ is correct... I'm pretty sure those fasteners to the wood don't work.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[gte447f]

That stair, the guardrail, and the OP all look like a middle school shop project. Start over and try again.