That time a whole wall bowed out on me near Denver

Last month I was working a retaining wall job in Lakewood, Colorado, and the second course started leaning bad after some rain. I had to rip out 20 feet of block and start over with better drainage behind it. Has anyone else run into trouble with clay soil pushing walls out like that?

2 comments

2 Comments

wesley_fox927d ago

I gotta push back on that "pregnant snake" description, man. I think you're being too hard on the clay soil. Honestly, the wall probably failed because of bad base prep or not enough geogrid, not the dirt itself. I've built plenty of walls in Denver on pure gumbo and they held up fine for years because I dug deep and used the right drainage from the start. @benlewis, maybe the real issue was your drain rock was too fine and it just clogged up, letting that bentonite do what bentonite does. People always blame the soil but they forget retaining walls are basically just big, dumb structures that need us to outsmart the physics. A little rain shouldn't wreck a wall if you plan for water from day one. So yeah, I get your frustration but I'm on clay's side here.

benlewis8d ago

Man I feel your pain. I had a similar disaster up in Fort Collins a couple years back where I put in a whole 30 foot section of wall, and after one good storm the thing looked like a pregnant snake trying to escape. Turned out I had about 3 feet of pure bentonite clay behind it that just turned to snot when it got wet. The wall bowed out so bad I could practically park my truck in the gap. Had to rip the whole thing down, dig a trench twice as deep as I wanted, and fill it with 3/4 crush just to get the water somewhere else. I swear half my life is just fighting Colorado clay and my own bad decisions.