Fall Peotection

[JStructsteel]

For a 5000lb fall protection load, is that also lateral or just vertical?

For a person falling over the edge, what amount of eccentricity do you use for torsion on the beam?

Thanks

 

[Struct123ure]

1. 5000lb is the unfactored load.
2. That is in any direction in a 360 sphere, use engineering judgement to figure out the critical direction Shear, Bending, Axial Tension.
3. Eccentricity is whatever the height or length of the anchor. Where does the person attach to?

 

[JStructsteel]

Thanks.

It’s an eye on a small column on top of the beam. The any direction answers my eccentricity question, it seems 5k left/right will impart a torsion on my beam.

 

[Once20036]

Recently a fall protection load was added to IBC. Its listed as a 3600# 3100# live load, which works out to 5,000# factored load.

I generally don't consider these to be "any direction" but rather, any direction where a fall load could occur.
For a typical rooftop application, that likely means a horizontal load in any direction. For a typical platform/tank access, that probably means a load downward around 45 degrees. I`ve never applied this load upward.

 

[BulbTheBuilder]

I will refer you to 4.6.5 ASCE 7-16
**Live load = 3 100lbf for each attached lifeline in every direction that a fall arrest load may be applied

You can also refer to IBC 2018 1607.10.4
**Live load not less than 3 100lbf ... in every direction that a fall arrest load can be applied.

Other threads here for additional info

https://www.eng-tips.com/viewthread.cfm?qid=498204

https://www.eng-tips.com/viewthread.cfm?qid=481438

https://www.eng-tips.com/viewthread.cfm?qid=509041

 

[lexpatrie]

Can the typo in the post title please be fixed so others find it if they search for fall protection?

 

[Once20036]

Thanks Bulb - you`re correct that its 3100# and not 3600# as I originally typed. I edited my post.

I`m not sure that I follow your interpretation of the directionality.
Did you highlight "EVERY DIRECTION" to mean that you think a load applied straight up would be appropriate?
I consider the latter half of that sentence to indicate that isn't necessary, and a fall arrest load couldn't be applied upward.

 

[BulbTheBuilder]

You're welcome, Once20036.

Did you highlight "EVERY DIRECTION" to mean that you think a load applied straight up would be appropriate?

The "every direction" is included in the clause of the code. Just something I wanted to point out to OP, so the design isn't limited to one particular scenario in case there's a possibility for other scenarios. I always consider "straight" and "non-straight", say "biaxial" to capture different limit states.

 

[aatmunn]

You're welcome, Once20036.


The "every direction" is included in the clause of the code. Just something I wanted to point out to OP, so the design isn't limited to one particular scenario in case there's a possibility for other scenarios. I always consider "straight" and "non-straight", say "biaxial" to capture different limit states.

Thanks for clarifying that! It’s good to know we should be looking at all possible load directions.
In your experience, have you come across any common mistakes that designers make when addressing eccentric loads in fall protection?

 

[BulbTheBuilder]

Thanks for clarifying that! It’s good to know we should be looking at all possible load directions.
In your experience, have you come across any common mistakes that designers make when addressing eccentric loads in fall protection?

You're welcome.

I haven't reviewed lots of fall arrest designs by other engineers so I can't say much on common mistakes.

But in my experience, I provide anchor reinforcement in concrete for the connections even if concrete breakouts/pullout works without the reinforcement. Have a bunch of #4s in there for my sanity is worth more than the cost savings.

For steel, I just check the supporting beam per ANSI 360 J10 for local strength.