We’ve moved the entire house structure back about a foot to get as close to the shoring wall as possible. Since the foundation is constructed literally against the shoring wall, and the shoring wall is not square or flat, we’re going to have to use extra shotcrete to fill the gaps. We are also changing the back garage walls (which are just the foundation wall) so that they are not square with the rest of the house. The left garage will be 9” deeper than the one on the right, and the wall will not be straight. Oh, well.
The wing walls are still going to be more than 2 feet away from the shoring wall. We talked about ways to form the wall on both sides, and link it to the soil nails in the shoring wall…and the cheapest solution seems to be simply filling the space with concrete. So the wing walls will be 3 feet thick.
Here is a drawing from the surveyor, showing the house location as designed, and the actual shoring wall. The grid on the left is the front driveway.
The left retaining wall is on the top, and the cross-hatched drawing is the actual shoring wall. It’s easy to see that the wing walls extend far wider than designed, because they were dug deeper into the hillside. The gap between the shoring wall and the actual wing wall at the front of the house is really visible. Also, the shoring wall was only supposed to be 4 inches thick, and it’s clearly 1 to 2 feet thick in nearly all areas. So far, we estimate that the errors in the shoring wall will cost us an additional $40,000, in materials, surveying, design time, and engineering time.