Work has proceeded over the last two weeks to finish the final 6 feet of shoring wall. The crew installed drain matting and wire mesh to support the wall material, while carefully removed the 4×4 shoring timbers and the fallen rock from the two cave-ins. Finally, they brought in the last loads of shotcrete and sprayed it into place.
Here is a closer look at some of the work. You can see the big cave-in on the right. The crew is wiring the sheets of mesh together, working from the left to the right. As they reached the cave-in, they dug out enough material to let them complete the mesh across the front. You can also see that there is 1 to 2 feet of space behind the drain mat and the mesh; they removed a lot more material than they should have when they excavated the final lift.
Of course, the space behind the wall needed to be filled in from the top. The best material for this is called “3/4 crush”, or crushed rock that is about 3/4” in size, which provides good drainage. This truck is delivering about 12 yards of rock, in preparation for filling the caved-in areas behind the wall — from the top.
Here is the final result. You can see the change in color at the edge between the last two lifts of the wall, and also where they sprayed shotcrete from different truck loads. As it turned out, they indeed had to use an enormous amount of concrete to fill in the over-excavated areas.
The shoring wall is finally done. They’ve removed more than 190 truck loads of dirt and rock from our land, and added dozens of mixers full of shotcrete and several truckloads of gravel. We now have a huge hole in the hillside, surrounded by concrete. It’s eerily quiet, and standing in the middle, where our house will be, I think this structure should be generating megawatts of power or something