Has anyone ever built using gabion retaining walls?  I was looking at using them for some retaining wall projects around my house.  I have the stones sitting that I can use to fill them to keep the costs down.

There is that engineer dude in Utah that had a thread in here, CRS can't remember his handle...

Boy, it's a good thing you remembered three letters....

Normally I can't remember that much, lol.

What's the question OP?  I've got about 200' of fence going in my back yard right now, it's a fence and not retaining any soil, but it's easy to retain soil with them too.

It took me four minutes to remember 3 letters

Where did you purchase the cage material?  Premade locally and then filled them yourself?  What would you recommend filling them with?  I have access to alot of mountain stone in my woods that I would be more than happy to put to use.  Is there a size of stone thats too big?  Do I need to put a footer in?  I have read that if the soil is packed hard I won't have to and could place them on the ground?  I plan on making a couple of walls 3 foot tall and about 30 to 50 foot long, would I need vertical support?  Do I need anything in the back for drainage?  What about landscape fabric to block dirt?  Or is it as easy as I am reading?  Build cages, fill them and back fill?

This gets a bit tricky for me.

If used wrong these are dangerous as retention structures, I’m a licensed PE but I don’t have nearly enough info to give you appropriate advice on your application.  So I don’t mind describing how I did mine, but you need to understand that mine is a fence that is not retaining anything and is not designed to retain anything, it’s just a really heavy fence.

I used 16’x5’ horse panels with 4”x2” spaces.  Combined with 6”+ river rock it works pretty well.  I used hog panels (far cheaper than the horse panels) and cut them up to make the top sides and centers of the baskets, we have a hog panel partition every 24” in the fence.  I used #9 sized hog rings to build the baskets and bought a large hog ring crimp on Amazon to install them.

The real trick is how and where you set them so they don’t settle, spread or relax and collapse.  The baskets seem pretty tough, but over time the rock fill will prove able to stretch the baskets out of shape.

Here’s a build thread-
Fence build

Because I didn't know what a Gabion wall was...

Attached File

I was going to describe how I build mine. I use them for erosion control in concentrated flow areas. SCW just described nearly exactly how I build them. I use cattle panels vs horse panels (larger holes but much cheaper, even cheaper than the hog panels). For my bottoms/sides I just cut a cattle panel down to the width I desire. The cutoff portion then becomes the bracing between the sides. It's not a full height piece, just a foot or so. It's only purpose is to keep the sides from bowing out. But if you desire pleasing aesthetics then you will need full-height braces and you'll need to place them more frequently. I don't care what mine look like, they're mostly underground anyways.

If using for erosion control or retention walls you have to have the heavy felt fabric too.

Wouldn't it be easier just to buy them premade?  I called a couple places and they didn't have them.  Are you guys worried about the panels rusting?  I only need to go 2 or 3 foot high and then I plan to back fill so they won't be holding alot of weight.  What can I assume the lifespan will be here in Pa?

Yes, it's definitely easier... until you price premade gabions, pass out from the shock, crack your head open on a rock, and spend weeks in the hospital.

I'm on a budget. Premade gabions are insanely expensive for some reason and usually you have to order them in so figure on buying a full skid of them plus freight. Between 2 local stores I found everything I needed except the heavy gauge hog rings.

Hog/horse/cattle panels are made of galvanized steel just like most gabions. I've been using the same cattle panels as a trellis for peas in my garden for 10 years now. I just noticed the bottoms starting to get rusty. They will probably last at least another 15-20 years...

Whats the dimensions of your gabion wall?  I am thinking of a 2 foot wide by 3 foot tall wall.  Did you use landscape fabric before you backfilled?  What size stone did you use?

The term "wall" isn't really applicable to my use so I will elaborate.

My property is almost all highly erodable land, with high slopes. At my field edges the concentrated flow areas were washing out and those washouts were creeping further and further up hill into the fields. At the field edge I dug a 4 foot deep, 3 foot wide, 16 foot long trench perpendicular to the water flow. I lined the trench and the outflow channel with fabric then built a 4x3x16 basket made of cattle panels. Then I filled the basket with rip-rap (6-12" limestone rock). As I filled the basket I alternately flipped the fabric up and back filled above the basket with dirt that I packed well to form what would be the collection bowl. Then I lined the collection bowl with fabric and layered 10-14" deep with rip-rap. The idea is to keep the grade above the basket low so the water runs slowly and doesn't erode the fields. Then, at the basket filled with rip-rap there is a quick 4 foot drop that gets the water back down into the original channel, but at the drop it is all protected by the rip-rap and fabric.

I've done 5 of these structures on my property now. I have 1 more to go but I ran out of time last year and it got wet on me. Because my property is so sensitive to erosion I can't do this work when it's wet or I will make a muddy mess that will never recover. My final one will be the largest yet with a significant concentrated flow through it (it drains around 80 acres). I haven't decided fully on how I want to do it but I may make a large U-shaped basket because of the location and the way the channel is growing. That will require 9 cattle panels @ $14 each to get me 48 linear feet of gabion structure...

The rock is by far the most expensive part of this. It's costing me around $12/ton delivered. I had 120 tons delivered for the 5 I did last year and I have around 15 tons left. I will probably need another 80 tons for the final spot.

I scouted around and found only Gabion walls, not retaining walls.  There's a difference.

Not really, it's just how you use them.  The calculations for using a gabion system for retaining a slope are the same as any gravity wall system like concrete blocks.\

It's the footer (the base) that seems to be different.  In my locale, the mandatory footer is proportionately really W I D E.  These Gabion walls don't seem to have a footer at all.

The physics is different. A thin wall wants to flip from soil pressure. A stepped gabon wall that's 3 feet thick does not have the same forces, and is porous so there is no hydraulic pressure.

How well do they handle earthquakes?  The soil is still only on one side and it will be wet soil slapping around during the quake.

I was told the engineers evaluate your plans for retaining walls assuming the wall was filled to the top with water (like a dam).

Gabion and rockery walls out-perform their engineered expectations, according to Cal-Trans.  They came up with a bunch of calcs to estimate the seismic loads then went to great lengths to describe that none of their expectations were met, walls do surprisingly well in seismic events.

That certainly gets weird.

Well, they are flexible, unlike cinderblock.

Yeah, that's certainly part of it.  I think the other big part of it is estimating loads.  For a typical structure you're looking at how heavy it is and how far above ground it is.  Getting that nailed down on a steep slope....  How would you estimate the weight?  the weight of all the ground retained?  Just the rockery wall?  What's the height?  What kind of response?

CalTrans did some calcs and then they went around and looked at damages to walls and tried to close the loop on their calcs, and never got very close.  The paper I read most recently (several years ago) pretty well bailed out of the idea of calcs and recommended construction methods they found were working well.

How big of rocks are you guys using?  I have some nice size natural stone in my wooded part of the property.