Eye-Bolt Through Channel Web 1

[wijgeng]

Hi,

I am not sure what the technical term is, but I am curious if anyone has experience with bolting an eye-bolt through the web of a channel.

We are trying to find a tie off point for someone which needs to be rated for 5,000 lbs. We have since decided on a different option, but one of the ideas discussed was to drill through the web of a channel and install an eye-bolt for a tie off. I'm curious what the structural checks would be in this situation? Web bearing due to the bolt? Any local bending or crippling?

Is practice common?

Thank you!

 

[dik]

I would think an application of an eyebolt through the bottom flange would offer greater resistance. Webs are generally thin and you could introduce torsion into the channel which they are poor at accommodating. The application of the vertical load through the shear centre of the channel if static would minimise torsion, but a dynamic load would likely load it differently.

Dik

 

[SwinnyGG]

Unless I am visualizing this in an odd way, using an eye bolt in the web also means loading the eye bolt in bending- this is a no-no.

Eye bolts should always be loaded axially, in anything other than a last-resort situation.

 

[jayrod12]

Around here, the code stipulates that the load must be applied in all directions to ensure the most critical loading sequences are checked.

We would not use an eye-bolt the way you describe. We have previously provided a piece of plate welded to the supporting steel with an opening for the tie-offs.

 

[bridgebuster]

I agree with dik; bolting through the flange would be better. However, if you're going to bolt through the web, I would suggest bolting a swivel plate - the kind used for lifting tilt-up panels - to the web.

 

[WARose]

[blue](wijgeng)[/blue]

I am not sure what the technical term is, but I am curious if anyone has experience with bolting an eye-bolt through the web of a channel.

...............

Is practice common?

I've seen something similar. Typically in a prefab metal building. (Except that it would be bracing for lateral loads, it would be going into wide flange columns, and it wasn't a eye-bolt at the end (just nuts).)

[blue](wijgeng)[/blue]

We are trying to find a tie off point for someone which needs to be rated for 5,000 lbs. We have since decided on a different option, but one of the ideas discussed was to drill through the web of a channel and install an eye-bolt for a tie off. I'm curious what the structural checks would be in this situation? Web bearing due to the bolt? Any local bending or crippling?

Definitely localized bending in the web (not to mention shear) would be very important checks. And with an eye-bolt.....if I didn't have a nut in front of it (in contact with the web)....I'd minimize the contact area by which the force was being applied. If not, you could initiate deformation in the web as it tried to pull through.

Also (as the others have said) you typically don't see an eye-bolt used for this (in bending). I'd just use nuts at the end of a threaded rod. (And into a flange would be better.)

 

[wijgeng]

Great information. I agree that it isn't an ideal loading situation and that is probably why I haven't seen this before. Thank you all for your insight.

 

[thaidavid40]

Double-check your OSHA design load requirements. For "engineered systems",OSHA only requires an ultimate load capacity of twice the maximum equivalent static force. For most self-retracting fall limiters ("yo-yo boxes") this load is limited by ANSI to no more than 900 pounds, That means that your anchorage point need be good for only an 1,800-pound ultimate load - not 5,000 pounds.
Dave

Thaidavid