Outlet pipe sizes in retaining walls
Outlet pipe sizes in retaining walls
(OP)
I have a 14' tall granite rubble wall that I've designed and on site there is a 60" outlet pipe they want to run through the wall. I'm not sure how that would work. I think that at the location of the pipe there is no soil so there is some help there but that's a pretty big hole, almost half the height of the entire wall. I'm thinking about placing reinforcing around the hole and also providing a concrete collar around the pipe. Are there any guidelines on max sizes for holes in walls like this?






RE: Outlet pipe sizes in retaining walls
No guidelines that I'm aware of - just engineering principles.
Your idea of a concrete collar to protect the pipe from shifts in the rubble wall and crushing pressures sounds appropriate.
Design the concrete donut to take vertical crushing force from the weight of the rubble above it.
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RE: Outlet pipe sizes in retaining walls
RE: Outlet pipe sizes in retaining walls
RE: Outlet pipe sizes in retaining walls
RE: Outlet pipe sizes in retaining walls
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RE: Outlet pipe sizes in retaining walls
I don't envy you this problem. Feels like you're heading for cowboy judgment territory. I'd recommend placing a call to somebody who manufactures related product like redi-rock. One would think that their engineering department has dealt with this before. When is picture
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Outlet pipe sizes in retaining walls
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RE: Outlet pipe sizes in retaining walls
JAE was definitely correct I said an impossible 60' in the original post :(
RE: Outlet pipe sizes in retaining walls
RE: Outlet pipe sizes in retaining walls
The pipe (small tunnel) is hopefully man enough for the over burden pressure but in terms of the wall it just replaces some of the stones.. If it was a hole that needed support then that's a different matter, but I'm having a little difficulty understanding the wall and its cross section.
Is this a 90 degree triangle wall or an equilateral triangle wall?
Could you use gabions behind the front surface to give you more stability?
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RE: Outlet pipe sizes in retaining walls
RE: Outlet pipe sizes in retaining walls
RE: Outlet pipe sizes in retaining walls
I think you need to consider a cutoff wall to handle underseepage and I am wondering how you intend to keep the rock on top of the pipe from sliding off. Given all that, perhaps a 14 foot high headwall with a cutoff wall and apron would be a better idea.
RE: Outlet pipe sizes in retaining walls
I can't see a pipe causing any really issues other than being a potential leak path and lack of friction for the rock mortar wall.
A few plates or bars welded on ( if it's metal) or rouging up the concrete it it's concrete to get a good key would seem like a good idea.
Can only assume this large pipe won't have any expansion or thrust / movement?? That could bring down your wall.
If it's a thin steel pipe then check the overload capacity, but if it's buried in soil coming into the wall it's almost certainly OK.
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Also: If you get a response it's polite to respond to it.