Ground Improvement

Location: Fallbrook, CA

Project Partner: Mesa General Engineering

Challenge: Shoring installation of a lift station for a new sub-division being constructed in Fallbrook. The lift station location was shown to be in an area susceptible to seismic settlement.

Overview: Condon-Johnson was contracted to design, construct and excavate a water-tight braced sheet piling shoring system for the lift station and wet well, as well as stone columns to mitigate liquefaction induced settlements.

Results: Condon-Johnson installed 30 foot long sheet piles along the perimeter of the lift station, 34 foot long sheet piles along the perimeter of the wet well, excavated the lift station 8.5 foot below grade and excavated the wet well to a depth of 24 feet, and placed a tied down seal slab in the wet well. Additionally, Condon-Johnson installed 116 ea. 36-inch diameter bottom feed stone columns installed to a depth of 55 feet below existing grade utilizing an 8 foot square pattern.