Properties of Soil in the San Fernando Hydraulic Fill Dams

Results are presented of extensive field and laboratory tests on soils from two old hydraulic fill dams that were damaged during the February 9, 1971 San Fernando earthquake. The data include standard penetration, absolute and relative compaction, relative density, static strength, and cyclic triaxial test results for both the hydraulic fill silty sand and the natural silty and gravelly sand alluvium. The relative densities of the hydraulics fills ranged from about 51%-58% and the relative compaction ranged from about 85%-92% of Modified AASHO maximum density. The relative density of the alluvium was about 65%-70%. Other properties were consistent with previously published data from other similar soils at similar densities.