This project involved foundation underpinning work providing foundation stabilization to 7 homes at the end of a cul de sac in San Diego, CA. Each house was underpinned with cast in place grade beams. The houses were then mechanically jacked level with lifts ranging from 3 to 8 inches using a system of hydraulic jacks and sacrificial screw jacks. A total of 55,000 lbs of rebar were installed. In addition approximately 740 cubic yards of concrete was poured, along with the injection of 65 cubic yards of pressure grout to fill in underneath the lifted slabs.
I’ve always wondered what they use to do underpinning. It makes sense that they would need some big hydraulic jacks to push screws into the ground! I can see why a job like this would be best done by professionals.