Chain Link Falling Boulder Restraint Fence Design 2

[2be]

I am designing a fall restraint fence to capture loose boulders (that might be dislodged in a seismic event) from a rock wall 6m up a 30deg slope. I can design the posts based on energy principles and acceptable energy losses for the slope I'm working on. I do, however, need to design the proposed chain link fencing to span between the posts, the spacing of which will probably be determine by the link capacities. Where can I access fundamental fencing capacities? Thanks. Thor

 

[SlideRuleEra]

Chain Link Fence Manufacturers Institute
Check the "Product Manual".

http://www.SlideRuleEra.net

 

[2be]

Thanks

 

[DBronson]

2be:

You might chek out Maccaferri - they make chain link products expressly for you application:
Link

Regards,

DB

 

[LittleInch]

I think your problem is going to be how many boulders.

Most systems are only based on one and the the fence gets repaired.

Otherwise you end up with some sort of monster fence.

This looks interesting

https://www.sciencedirect.com/science/article/pii/S1674775518300143

http://www.concrib.com.au/rockcatching_barrier.php

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[phamENG]

It may be worthwhile to consider a range of boulder sizes. If the fencing can't take the worst case, then you could run steel cables down low like a security fence for vehicle exclusion. Design that to take the big ones, and the fence to take the smaller ones. Only problem there is that it may be tough to predict the height of impact without a really detailed cross section of the slope. Though, even then, the slope may change shape in a seismic event. In that case the rock catching barrier link from LittleInch looks pretty neat.

 

[STrctPono]

Anytime I've seen this done, the attenuator fence uses a wire mesh fabric like one that Geobrugg makes. I've never seen it out of chain link. Not saying chain link won't/can't work but the wire mesh made by companies like Geobrugg is specifically made for this type of stuff and I would imagine that they would have a lot of information to share with you. They aren't the only ones, just one company that we've dealt with before. Also, how are you anchoring your posts? Typically these are tied back to the hillside with some rock/soil anchors.

 

[bridgebuster]

These drawings may be of help, NYSDOT standard sheets for rock catchment systems.
Link

 

[EdStainless]

I helped a buddy with a failure analysis on one in PA once. The cables strung through them are what catches the boulders, the fence holds the cables in position and prevents large fragments from falling further.
Our analysis centered on the corrosion of a cable anchor.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy

 

[nackra]

A few years ago I worked on a project that installed 5 debris barriers:

https://www.geobrugg.com/en/Rockfall-protection-barriers-GBE-7953.html

 

[2be]

Excellent ideas. Thank you. Thor