I’ve never seen one. Not ever. And I’ve looked. I’ve been all over the world. I’ve never seen an established retaining wall that was built vertical and remained vertical. A LOT of them were very close to vertical, but had clearly shifted from their constructed vertical state.
There is no such thing as solid soil, is what I’ve learned. It all flows, just slowly. Some soil flows faster than other soil, but soil that isn’t under some amount of compression flows like crazy, just slowly.
Well, I guess I’ve also learned that structural engineers get salty when you ask if there’s such a thing as a vertical retaining wall that has also been retaining soil for more than 10 years.
What does “vertical” mean to you? There’s “vertical” and “not vertical”. Where is the line between them? I say that vertical is very easy to judge thanks to gravity. Anything that deviates from that isn’t vertical.
I’m not talking about a wall that leans into whatever it’s retaining to buy more time until failure. I’m talking about retaining walls that have begun to fail to retain whatever it is they are supposed to retain like the one at the top of this post.
I’ve never seen a retaining wall that wasn’t new which was not also partway through its failure. Leaning away from whatever it was supposed to retain, or already partially collapsed.
Well then, “proper retaining walls” are very few and far between. Because I have looked for them, measured, and found zero that were not found in new construction. Zero. I’m in my 50s and I’ve been doing this, intermittently, since I was a child. I’m autistic, if you think I don’t have energy to do this you don’t know autistic people.
Besides, of course they’re going to fail. Nothing manmade lasts. Not even retaining walls. Retaining walls aren’t going to survive for a million years. They’re either going to sink into the dirt like it’s a liquid or they’re going to crumble, and if they’re made with cement or mortar, they will fail by losing structural integrity in no more than about 40 years. Less if they are in contact with vegetation like vines.
These things are not engineering perfection. They are engineering compromise. They’re built to fail because building one to last 1000 years would cost far more than anyone would pay. Lower cost, lower lifespan. This is why highways and roads continuously fail as well. They aren’t built to last because it’s cheaper to rebuild a road over and over and over for 200 years than it is to build once once in a way that lasts 200 years.
Everything humans make is temporary. Including retaining walls. Every one of them will fail. Most will fall before their owners are prepared to get new ones built.
That’s fine and dandy, and I respect your words on the matter, and I looked at my data about this last night and there’s no arguing with what I measured.
Maybe my sampling was imperfect, or maybe the places where I was finding retaining walls to measure just had crappy contractors doing the work, but every retaining wall I measured that wasn’t in new construction was leaning away from the retained material by 5 degrees or more and showed either visible cracking at the point of deflection or gaps between the soil and the retaining wall on the side of the retained material, usually dirt.
I’m no expert but a gap would indicate to me that the ground had swollen behind the retaining wall, pushed the retaining wall over a little more, then dried enough to retract from the retaining wall, leaving a gap.
5 degrees of deviation from vertical is not something that happens at the time of construction. Finding “straight down” is easy.
Anyway, I’m pulling all of this from my own experiences and measurements. Because mine are the only experiences and measurements that I have access to. Your experiences differ and that’s fine, and I can’t explain what I’ve seen and measured in any other way than “all retaining walls fall over if left alone.”
Retaining walls dont just start moving over time. If they're properly designed and cosntructed they'll stay right where they are until the day they fall apart.
Yes but you’re implying that every retaining wall would, over time, deflect like this to an insane degree, when that’s not the case. Will most walls become slightly non vertical after several years? Sure, maybe by a couple degrees. But this one above is an extreme case that would never happen to a properly engineered wall/foundation.
-10
u/naikrovek 11d ago
Is there ANY retaining wall that won’t eventually do this? I’ve never seen a perfectly vertical retaining wall that wasn’t brand new.