Gabion wall repair - toe reinforcement

[McStorm]

Does anyone have experience with repairing gabion walls that have rusted and failed at the bottom? We have many sites throughout the St. Louis area where the bottoms of the baskets have rusted and opened, even with the coated baskets, because the coating gets knicked during construction or by gravel flowing along the stream, then the road salt takes care of the rest. In some places, the rocks have washed out and now the upper baskets are "hanging", but have not failed. In these locations, we were hoping to repair the toes, but with something other than gabion wire, since it will likely fail again. One idea was to form a concrete toe with a flowable fill, but not sure if that would be permittable or if it would have enough compressive strength to hold the weight from above.

Any help is greatly appreciated!

 

[GoldDredger]

That is an interesting problem, I always wondered what would happen in that situation. Here in Dallas gabions are often used for walls of detention ponds. It seems to me once those wires start corroding the problems begin, and much sooner, than had it been concrete construction.

I don't know the solution, but I do know Maccaferri seem to be the preeminent manufacturer of gabion baskets. You might contact their experts to see what solutions are available.

I worked with a helpful representative from Maccaferri named Steve Hoff at 972-436-2974 on a gabion project I had. He could probably answer your question or put you in touch with someone.

Keep us posted on your solution, I would be curious to know what you do.

 

[McStorm]

Thanks GoldDredger!
We did talk with one Maccaferri rep who was not so helpful. According to him this "never happens", but maybe a different rep would help.
I appreciate the contact info and I'll keep you posted!

 

[GoldDredger]

Would be great to post a picture or two of the area in question, so we can all see how 'this never happens'

 

[dicksewerrat]

Maybe,drive interlocking sheets down and backfill with concrete?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[Prepakt1]

You could grout the area and turn the bottom rock into prepakt concrete.( you can get similar strenghts to normal concrete). The main problem is containing the grout. to do this you would use normal formwork. Steel; or wood or sheet piles. Where this is not possible. (Below water), you can use a fabric formwork to contain the grout. It all depends on what condition the gabions are in and access. For enviornmental reasons it may not be possible to grout.
If grouting is permitted, it may still require environmental monitoring to ensure the the water ph level does not exceed local requirments and kill fish in the area.


Intrusion Prepakt /marineconcrete.com

 

[McStorm]

Thank you all for the ideas! Here is a photo showing one problem site. I don't know why the upper baskets are still level, but I assume it is due to something anchoring it into the slope. I believe these were built in the 1980's, and there are complaints of failures in 1997, where they did come back and form a concrete toe, but the environmental regulations were not as stringent back then.

We were theorizing that we could isolate the area with sandbags or something less permeable and pump out the water until the grout cures. As you can see, there is not much base flow. The problem would be if there was an unanticipated rain event.

Is there anyone in the St. Louis area or Midwest US who does the prepakt concrete?

Any other thoughts besides grout/concrete?

Thanks again!

 

[Prepakt1]

You should be able to do this with fabric formwork .As long as the flow is not to great its probably possible to grout or use micro concrete without pumping out the water.
There is a few alternative ways to do this type of work.
I would advise doing a few area perhaps 18" wide to begin and form water stops and then grout the larger areas between. If the water flow is high then you have to slow it down by minimising void spaces to do this you can vibrate in pea gravel which will give the grout more ability to bind the mass together. In one project an underground river 80 ft down where we wanted to stop the flow/ We started with 6" rock dropped through drill shafts and then went to 2" rock and finally pea gravel.There is also some special chemical additives that expand and block voids.

Intrusion Prepakt /marineconcrete.com

 

[GabionGuy]

Be very careful how you approach the repair on the gabion wall. why were gabions selected in the first place? If drainage of the retained soils was a design condition, then filling a gabion with concrete will defeat the whole purpose.

We have successfully repaired gabion walls with similar problems using thin gabion unit as facing or formwork and placing grout or concrete in behind.

You should contact the Maccaferri technical office in Williamsport, MD for this type of problem. The area offices are usually sales people, not engineers.

 

[Prepakt1]

If drainage is a problem You would place drain or grout tubes through the gabion into the backing material. Then grout the gabions. You would then drill through the end of the tubes to ensure that the end of the tubes in the backing material are not blocked and provide good drainage

Intrusion Prepakt /marineconcrete.com