Katya Coad wrote:Yes, I think they are going to be fine. I didn't sledge them, but I did pack them fairly tightly and stomped on the sand as I lay it in, tucking it in around the edges too. I've since piled some heavy boulders on top to create a rock garden. Anyway, thanks for your feedback.
Hi Katya,
We had some worrying experience with earth rammed car tires for wall retention purposes. The dirt we tried to retain got very wet during heavy rain, and although all tires had carton in the bottom and a batter of around 2.5 inch per two courses (very steep), it blew out. Admitting it was too high (16 courses) and too long in the straight part (25 feet), the lesson was clear.
If you try to retain dirt below 6-7 feet, and that dirt is loose and it can get (very) wet, don't use small car tires with dirt and carton bottom. Use lorry or truck tires filled with gravel and double plastic bottom. And batter heavily, each course around 10 inch more inward than the previous.
If the ground you need to retain is stable and compacted, and you don't have a lot water issues (where no rain water will not collect behind the tires), I guess smaller tires and gravel with plastic will do too. Even a slightly steeper wall would hold.
Note, I assume that you used bigger tires at the first 3 layers or so. And that every tire is leveled and battered. (wall should be level).
This is not exact science, except that the code for tire walls has all to do with rammed earth or gravel, plastic/carton bottom in each tire, leveled and correctly battered walls. Also know that slightly bend walls are stronger.
I hope it all holds together and this helps you to decide to go with the current wall, or to redo it.
Kind regards,
Sijmen
