Hi William.
Now you probably know what my typical response is to using tires in the environment, so take it as stated. I haven't changed my mind with regards to tires and food production. However...
Used tires with the sidewalls cut off, then somehow connected to make a large mat would definitely work to retain fill in the case of a roadway or driveway, even if you basically made a used-tire honeycomb path that you recessed about the width of the adulterated tires and then filled with gravel and sand.
I think that if you filled some, or all, with inoculated woodchips, you might end up with a very practical short- to medium-term solution for paths and roadways that, because of encouraged fungal populations, end with a strain of mushrooms that thrive on the degrading rubber.
I think I would prefer this use to one where the tires are aboveground, personally. Also, glass bottles will probably shatter, wrecking all of your effort, should you try to knock off the necks with a hammer without scoring them, and perhaps even then. In the case of glass bottle tire fill, I would try having two courses of bottles per tire, such that the bottom course is necks-up and the top course fits necks-down into them.
I was thinking about using broken bottle glass as fill, and if you had a cement mixer and some coarse sand, you could break and tumble bottle glass as a translucent pebble fill for the spaces between, or even for a pourable translucent fill atop a bottom course of bottles.
Imagine a skylight made of a bottom course of bottles fit and chinked tightly into a tire, filled with a solution of water and, I don't know, vinegar or something else that would inhibit algal growth, and then filled with a tumbled glass fill. Imagine that tire-and-glass skylight installed into a WOFATI, sunken into the roof so that soil and grass cover over the tire entirely, so all you see is a pile of tumbled glass from the top.
I also wonder if such a tire-mat honeycomb could be used between two moisture barriers to form the dry-fill earth umbrella of the WOFATI. A honeycomb structure of wall-less tires might make a WOFATI much more structurally sound, especially in quake-prone areas. Plus, it would enable one to safely design holes down through the WOFATI for added ventilation and light. Care would still need to be taken when sealing around the holes in the moisture membranes, but I think it would be much more forgivable, structurally.
I also think that cutting off the sidewalls is a great idea if you're going to pack tires, and I don't think I've mentioned that yet, so kudos. I think a giant cookie cutter would be the best way, probably something easy enough to move with one person (rolling on its side) with a blade on the bottom that is positioned atop the tire to be cut. There would be a platform on top, where the operator would jump, and that would cut the sidewall.
Despite my reservations, I think the best place to use tires in this fashion
is woven together as a geotextile mat for high-traffic areas, and in earth building where cement-style forms won't work (and where there's a glut of tires). If you chop out the tire walls and ram earth in layers into successive courses of tires, the rammed material essentially forms into a monolithic piece within the tire honeycomb, acting as rubber-coated rebar. If this was sealed within a waterproof natural plaster that could be reapplied at need, I would feel quite happy with the result, I think, both structurally, and from a health standpoint.
I could even see this used for reinforced earthdams, though I would want to use something like pond liner overtop of an earth plaster coating to keep the compacted fill from washing away over time.
As there exist so many of these things, I think responsible reuse might be an important piece of the whole remediation puzzle. I think encapsulation is probably the safest option for use in the immediate term, but I think that, if used in non-sensitive areas as interfaces to the environment, and even encouraged to act as soil life bioreactors by the addition of woodchips,
compost extracts and fungal slurries, we may end up, over time, fostering the development of organisms evolved to clean up contamination because they have evolved to find it tasty.
And as I think about it, I wonder if, with the right mineral-based plaster and compatible lichens and mosses, some encapsulation strategy could be devised that would leave rammed-tire fences looking either stone-like or lichen-covered.
-CK
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein