industrial handrailing to steel beam fixing 1

[phuduhudu]

I am trying to do a detail for the fixing of handrail posts to steel beams. How would you determine how far down the web of the beam to put the stiffener plate for a side fixing to the beam? Also when fixing to the top flange of the beam and fixing to one side of the flange I would have thought I would need a bearing stiffener under the flange again. I am sure this is the kind of thing that guys with experience of installation just know but I don't!

 

[SlideRuleEra]

Unless the beams you are concerned with are really small, the potential loads on the handrail are trivial compared to beam capacity. Suggest that you locate the handrail mounting plate at the web's neutral axis. This has more to do with letting the welder have clear access for installation than structural capacity.

For the same reason, a true stiffener plate under a flange-mounted handrail post should not be needed.

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[graybeach]

I think it depends on the size of your beam. Loading on the handrail causes torsion in the beam If you beam is heavy, you may be able to attach to the top flange with no stiffeners on the beam. If the beam is light you may need stiffeners attached to the top and bottom flanges so the flanges can form a resisting couple. You may need to take further measures to prevent the railing from being too flexible.

 

[phuduhudu]

Thanks for the quick one Slide Rule. I did a quick yield line analysis and as you say the loads are trivial. If you have deep beams and you mount at mid height of the beam then you could have considerably longer handrail posts. Surely it is more economical to have the side mounting plate up to the flange.

Then while I am on handrails another one that I often disagree with contractors over is the fixing to concrete edges. Contractors always want to core drill the concrete but this risks coring the top reinf so I would prefer them to cast in a sleeve for the post. Any good ideas on this.

 

[SlideRuleEra]

phuduhudu - Access for installation is the principal concern. If it is practical for a welder to get to a web mounting plate that is "pushed up" under the top flange, then no problem. However, in industrial application there are often items such as piping, equipment, electrical conduits / cable trays that are located adjacent to walkways and platforms (with handrail) - be certain that these will not be in the way. This is true no matter how or where the handrail is attached.

On the concrete, I agree with you that cutting rebar is not a good idea. Many industrial facilities are designed with enough reserve capacity to make this a minimal problem. Suggest that you evaluate each job on a case-by-case basis. It may be less expensive to add a little more rebar than to put in a lot of sleeves.

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