You might find this section on handrails specified for the International Space Station useful:
1.02 PERFORMANCE REQUIREMENTS:
- General: In engineering railings to withstand structural loads indicated, determine allowable design working stresses of railing materials based on the following:
- Steel: 72 percent of minimum yield strength.
- Structural Performance of Railings: Provide railings capable of withstanding the effects of gravity loads and the following loads and stresses within limits and under conditions indicated:
- Handrails:
- Uniform load of 50 lbf/ ft. applied in any direction.
- Concentrated load of 200 lbf applied in any direction.
- Uniform and concentrated loads need not be assumed to act concurrently.
- Top Rails of Guards:
- Uniform load of 50 lbf/ft. applied in any direction.
- Concentrated load of 200 lbf applied in any direction.
- Uniform and concentrated loads need not be assumed to act concurrently.
- Infill of Guards:
- Concentrated load of 50 lbf. applied horizontally on an area of 1 sq. ft..
- Uniform load of 25 lbf/sq. ft. applied horizontally.
- Infill load and other loads need not be assumed to act concurrently.
C. Thermal Movements: Provide exterior railings that allow for thermal movements resulting from the following maximum change (range) in ambient and surface temperatures by preventing buckling, opening of joints, overstressing of components, failure of connections, and other detrimental effects. Base engineering calculation on surface temperatures of materials due to both solar heat gain and nighttime-sky heat loss.
Keep in mind the requirements that the ADA Guidelines make for the handrail diameter (1 3/4" is typically used) and that there be no obstructions within 3" above the rail and within 3/4" of either side. Essentially, that requires that the brackets supporting the handrails extend from below the rails. Although the IBC allows the brackets to be spaced up to 6'-0" apart, 4"-0" pacing (or less) makes for easier attachments and deflection control.
------------------------------
Robert Crossno P.E., M.ASCE
Civil Engineer Supervisor
Albuquerque NM
------------------------------
Original Message:
Sent: 03-17-2018 08:11
From: Tadas Saudargas
Subject: handrail bracket calculations
Hi Chad,
Following are two documents that I've found helpful for handrail design. Even though you may not find answers specific to your application, they both discuss the design philosophy and hopefully provide some guidance to those who stumble into this discussion topic.
1) Pipe Railing Systems Manual (ANSI/NAAMM AMP 521-01)
2) Technical Note: Comparison of Design Specifications for Design of Pipe and Round HSS Pedestrian Guardrail Systems (by AISC).
Very curious to see other contributions to this topic.
Cheers,
Tadas
------------------------------
Tadas Saudargas P.E., M.ASCE
Ambitech Engineering Corporation
Downers Grove IL
Original Message:
Sent: 03-16-2018 10:15
From: Chad Morrison
Subject: handrail bracket calculations
Does anyone have sources available for useful approaches for handrail bracket design? I have 10 years experience in producing calculations for various bracket types and base materials and continue to encounter the obstacles that I have from the onset of my career. Without testing of the bracket (and becoming the "approved authority") calculations are needed to justify the anchorage. Historical performance of handrail installations indicate that under most cases they are safe. One cannot prevent abuse and some maintenance during the rail's lifetime should be expected.
Producing calculations for handrail brackets fastened to concrete is fairly straightforward. Calculations for fastening to hollow CMU and stud walls prove more problematic. Before I share my methods, I am interested in how others approach the problem. What anchors do you use in hollow CMU? What safety factor do you apply to them? Do you specify wood blocking or metal sheets within the stud wall to fasten to? What allowable bearing strength do you use for GWB?
Please feel free share any questions or comments you have on the topic, as it does cover much more ground than expected. Thanks!
------------------------------
Chad Morrison P.E., M.ASCE
Professional Engineer
Greenville RI
------------------------------