This was an Emergency Caltrans project located on Hwy 50 near Bridal Veil Falls. This project consisted of 60 EA soldier piles, 30 inch diameter up to 60 foot deep. In addition to the soldier piles, this project included the installation of 110 EA tiebacks, ranging from 73 to 118 feet in length to stabilize Hwy 50. The subsurface conditions at this location were comprised of cobbles, sandy silt and granite.
This subcontract performed for the US Army Corps of Engineers consists of a 100’ deep permeation grout curtain for a control structure.
The Calaveras Dam Replacement project is a replacement of the existing earthen dam undertaken by the San Francisco Public Utilities Commission, with the general contractor as Dragados-Flatiron-Sukut Joint Venture. Drill Tech was subcontracted to perform deep soil mixing to stabilize the disposal site, to excavate a 154-ft deep shaft, five starter tunnels (12’ dia. x 60’ each) from within the shaft, and multiple soil nail, rock bolt and tieback walls to stabilize the abutment excavations and spillway. The ground improvement was performed using 238ea CSM panels up to 78 feet deep that were all keyed five feet into rock. The shaft was excavated with drill and blast techniques, and the tunnels were driven with an Alpine AN50 roadheader. The total quantity of soil nails, rock bolts and tiebacks on the project exceeded 100,000 lineal feet.