Deep Foundations

Location: San Diego, CA

Project Partner: Flatiron-Skanska-Stacy and Witbeck, A Joint Venture

Challenge: Installation of large diameter piling to 260 feet below grade in a lagoon with a top of permanent steel casing 26 feet below grade.

Overview: Condon-Johnson was contracted to install the drilled shafts for a two phase bridge replacement in San Diego. The first phase widens the freeway, then the original freeway is demolished and rebuilt in the second phase. The project consists of 17 each 10 foot diameter pier piles to 245-260 feet below grade and 44 each 5 foot diameter abutment piles to 165 feet below grade.

Results: Condon-Johnson has successfully completed the first phase of abutment piling (22 each) and will soon complete the west side pier piles (4 each). Numerous installation techniques were utilized to construct piles of unprecedented size and depth. Installation techniques included vibrated casing with an APE 600, oscillator and casing with a Soilmec SR-145 with VRM 250KL drill setup for the 5 foot diameter piles and a Liebherr 895 with Buma C3000G crane setup for the 10 foot diameter piles, and slurry displacement drilling with an IMT AF300 for the CMP top cans and a Bauer BG46 to excavate the rock socket portion of the 10 foot diameter piles.