I'm trying to work out a "rough and ready" calculation for the simple retaining wall below (about 1.00m high).
The structural engineer has designed a cantilever with a large heel, as usual, but on checking, it's hard to excavate under the retained bank to put a "heel" in. On the other hand, it already has a very large "toe" in the design, because there's a path going in front of the wall, so making the "toe" more substantial or adding a "key" beneath it to stop sliding would be much easier.
I'd like to get an idea about load calcs for replacing the usual "T" shaped cantilever with an "L" shaped cantilever as I've seen elsewhere, like this:
The physical dimensions we have so far (all in mm) are W1=200, H1 = 950-1050 varying along the length of the wall, W2 = 900, H2 = 300. The soil is London Clay (in London, UK), and the base is embedded below ground level which may be all that's needed to prevent sliding. I'm happy to do worst case assumptions and over-engineer for simplicity and durability, which would be fully saturated soil, active soil parameters, "worst case" clay, and poured foundation grade RC35 or similar concrete. Minor soil settlement isn't an issue, as it isn't being built on. The excavator can't quite reach to dig at the end of the toe, so if a key (if any) can be near the stem, that would be easier by far.
The current design is for a base slab about 800-900 front-to-back and 300 high, a uniform stem 200 wide, and 2 x A393 welded grid in each of the base and the stem with right-angle 10mm rebar connecting them, so I've taken those values and would keep the same reinforcement (they might be the best or not, I can't tell, but they seem reasonable?).
I'm hoping to find out what might be possible, and how to calculate any better options.
