OSHA Handrail (top rail) 200lb exac

[Cassidy G]

OSHA Handrail (top rail) 200lb exact location.

Hi! Good day Engineers.

I am design a OSHA stairs with handrail. I'm confused about 200lb concentrated live load, downward or outward direction.


For example top rail length is 25ft. I am planning to distribute the 200lb over the total length of top rail. And it becomes 8lb/ft acting in the top rail total length.

Can anyone give me advice.

Thank you.

 

[EngineeringEric]

Don't distribute the concentrated load. it is a point load, keep it as a point load. I forget, doesn't both OSHAs also have a 50plf requirement? (sorry can't find my copy from home)

Basically, everything needs to be able to transfer 200# minimum. the post. the rail to post. the rail. and then the rail needs to be able to transfer it.

If there is a 50plf requirement then if your posts are at 4ft o.c. they need to resist 200# or 4ftx50plf = 200# but if posts are 12.5ft apart the middle post will need to resist 12.5ft x 50 plf!!! Oh and deflection limits are a thing with OSHA design.

Call up one of the structural firms you work with and run it by them, or better hire a structural engineer. We can always use the work

 

[Cassidy G]

I'm sorry, I confused.

No OSHA requires 200lb only.

The distance between posts are 3.28f (1m)

You mean, in every post I should apply 200lb at the top rail. For example the stairs has 9posts. 9 of 200lb should be applied at top rail and post?

 

[JLNJ]

What if the load is right at an end post? That one post must resist the entire load.

The code says that the load could be anywhere in any direction. Find the worst case and design for it. This is a basic and simple tenet of structural engineering.

 

[Cassidy G]

Hi, Sir.

I'm just confused about the exact location of 200lb concentrated live load.

I though it should be located at every top of post.

 

[jayrod12]

You need to check the post for the load being right at the top of post. And you need to check the rail as if the load was mid way between posts.

 

[Cassidy G]

And I need to check for vertical and horizontal load Sir?

 

[Cassidy G]

Dear Engineers,

For example, the length of posts are 3.28ft and it has midrail.

Should I seperate the design of post with 200lb at the top and 150lb at the middle. Or I should design the the post with those loads acting at the same time?

I think that was the worse case.

Thank you.

 

[BridgeSmith]

The 200 lbs is a single load that can occur at any point along the top rail. The rail must be able to resist that load when applied at any point, but if the post spacing is the same everywhere, the critical location will be at the midspan of the end spacing (between the 1st and 2nd posts). It can also occur at a post, and the post must be able to resist the 200 lbs and the moment it produces at the base.

If you're still not clear on this after my reply and the previous replies, you need to consult a structural engineer to design the railing.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[dik]

The 200lbs can be applied to the post and for the rail, I apply the 200lbs to mid span and use PL/6 to accommodate the end span... for interior spans the Mp = PL/8. I also use the plastic section modulus Z. I don't think any additional loading is concurrent.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[jayrod12]

I agree that the load need not be applied concurrently in both directions. The lateral load will always govern the design of the items from my experience.

 

[dik]

The actual number is about 5.8...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[IFRs]

BridgeSmith nailed it with: "The 200 lbs is a single load that can occur at any point along the top rail." This answers the OP's question directly. The load may be horizontal or vertical - you have to check both. It can be anywhere so you have to find the worst case.

 

[r13]

Cassidy,

You shall learn how to simplify a structure, and always look for the loading case that produces the most critical reactions in the simplified structure.

 

[dik]

Slightly improved... and Mp = P x L / 5.8

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[r13]

You just couldn't get out of the hall (hole) of plastic design ! Now the OP is confused again.

 

[Cassidy G]

Yes, I understand Engineers. Thank you.

If it has mid rails, it should resist the 150lb.

If I will design the post, should I design it with 200lb and 150lb acting at the same time?

 

[Cassidy G]

The codes says, the stair landing live load should be at least five times the normal load or min of 1000lb.

The code give an example of 300lb worker (tools included)

The structure I'm design has stairs outside and the landings are cantilever. The landings dimension are 4.6ft x 9.8ft.

I used 330lb, then the normal live is 7.32 psf. And it will becomes 36.6 psf.

It is alright? Because it is overhang landings with no support at the ends. The design is already alright with the live load.

But I'm thinking that it's 5*330lb or 5 persons. 4.6ft x 9.8ft landing is big space, I'm thinking what if 7 to 10 persons standing in the landings.

Any suggestions, recommendations are really appreciated.

Thank you.

 

[r13]

Did code mention you need to do load combination in handrail design? Follow the code.

 

[r13]

I sense you are designing industry structures. If so, follow industry guidelines for specific requirement.