We got to use an Alpine Rockwheel last Thursday.
I didn’t get a pic, the above is a stock photo from Alpine’s website.
ROCKWHEEL ROCK & CONCRETE GRINDERS | Rock Grinding and Drum Cutters
Ours has a steel body between the tines and the quik attach (the black frame between the grey and yellow above) that is 13’ long. There is 3” steel pipe running down the back that we pump grout through.
The idea is to solidify the soil from the surface down to bedrock, before we start installing the lagging wall. So we were not using it for it’s intended purpose. But, it was able to mix the soil and grout down to the bedrock.
The building on the left has historical status, and it also houses backup power and servers for the Federal Reserve Bank. To the right of the steel ‘H’ pile is where the new building is going.
Example of a lagging wall:
We are going 34’ deep down from ground level. Even with the piling being 45’ deep, you still get deflection one way or another. Hence, mixing grout into the soil. Tomorrow, they will drive anchor rods thru the grout soil into the bedrock. Then we can start excavating.
Normally we would not have to go to such extremes, but the layers are 10’ of contaminated soil, 12’ of limestone, then sandstone after that.
