Soil Improvement to Support a Warehouse Building over Difficult Soils

A new warehouse building was planned for Home Depot in Camarillo, California. The geotechnical investigation at the site indicated the liquefaction hazard in loose sandy soil layers under the design earthquake and static settlement problems in soft clay layers under the building loads. The specialty geotechnical contractor designed and performed soil improvement at the site. Vibro stone columns were installed to mitigate the site liquefaction by providing densification, reinforcement, and drainage in the loose sand soil layers. Deep soil mixing columns were installed to support heavy building column loads. Liquefaction analyses were performed on the CPT records before and after the vibro stone column treatment. FLAC analysis on the soil mixing treatment was performed to optimize the mixing column penetration depth. Full size static load tests on soil mixing column groups proved that the FLAC analysis correctly simulated the site condition. This paper covers design methodology, production work, and quality control and testing, with supporting figures.