Handrail Base Plate
Handrail Base Plate
(OP)
Question for ya!
I'm trying to figure out if the baseplate I have for a handrail I'm designing will be sufficient. For some reason my units aren't calculating right. I'm using 1.5" steel tubing at a height of 48". I've calculated my moment at the center of the rectangular base plate to be 21 kip-in. If i want to use a base plate with the dimensions 2.5" wide by 4" long and an anchor bolt on either side of the handrail post, how do i make sure this thing isn't going to fail? I know it is based on a shape factor (S=bd^2/6) but for some reason my units aren't coming out correctly. Thanks for the help!
I'm trying to figure out if the baseplate I have for a handrail I'm designing will be sufficient. For some reason my units aren't calculating right. I'm using 1.5" steel tubing at a height of 48". I've calculated my moment at the center of the rectangular base plate to be 21 kip-in. If i want to use a base plate with the dimensions 2.5" wide by 4" long and an anchor bolt on either side of the handrail post, how do i make sure this thing isn't going to fail? I know it is based on a shape factor (S=bd^2/6) but for some reason my units aren't coming out correctly. Thanks for the help!






RE: Handrail Base Plate
Assuming the vertical load is negligile, the anchor bolt tension times the moment arm to the centroid of compression under the base plate would need to equal the externally applied moment. The thickness of the base plate would need to be sized to resist the bending caused by the compression under the plate or the tension from the anchor bolt.
Incidently, S=bd^2/6 is the section modulus and not the shape factor.
Make sure that you clearly understand the theory before trying to solve this problem.
RE: Handrail Base Plate
I mistakenly typed shape factor instead of section modulus. It has been a long monday.
So, I have my moment arm to the centroid of compression as (2.5"/2 = 1.25"). Where do I go from there?
RE: Handrail Base Plate
Consider also if your installation requires all of that load to be supported by a single post- quite often, the assembly will be adequate to distribute load around some.
RE: Handrail Base Plate
The force (lbs) in your anchor will be approximately M (in-lbs) / (0.9* 1.25") to approximate the depth of the compression block in the concrete base.
RE: Handrail Base Plate
DaveAtkins