huangyhg

horizontal load on handrail
the ibc states that a 50 plf be applied to the top rail of the guardrail. in a 3 span condition, i have seen it applied as a uniform load across the entire rail (3 spans) and i have seen it applied for just one span. anybody have a comment on this? i know that a minimum 200 lb concentrated load is applied anywhere along the rail not concurrently with the uniform load.
do it for the worst case.
i can't comment on the amount of load but i would assume it's similar to what we use in the uk. in terms of the design approach, applying the load to a single span will give a more conservative design moment compared to allowing for continiuty over the supports. in the latter case, the mid-span moment reduces and although you'll now get moments at the supports they would never be greater than the moment at the centre of a single span beam (if you have equal loading and equal spans). also in terms of constrcution it is not always practical to have one single rail and therefore the single span design takes account of this possibility.
your bigger question should be what country is the hand rail going to be used in? the worst case loading ranges widely in the world, it will also depend on it usage, will it be used as an anchor point or just a handrail. from what i have read on hand rail australia has one of the highest standers.
chris
"in this house, we obey the laws of thermodynamics." homer simpson
i would set up a spreadsheet or simple computer model with all your load cases input (panel load, top handrail load and one large concentrated point load), and make sure all your elements have capacity for these loads. in our office we try to limit our deflections to h/125 which allows us approximatley 10mm deflection and the top of the posts.
we had to retrofit and new handrail to an existing exit platform at a university and had a not-so-great detail where we bolted the handrail posts to the web of a channel section. the client asked us to come and and have a look at it because in there opinion it "flexed" a little. we went out and gave it a shake and i didn't think it was moving to far.
i can't upload the video, the size must be to large. i will just post a photo instead, the job is in australia.

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