Densification potential of unsaturated soils through cyclic loading and dynamic separation

This study investigates the effects of fine content and moisture levels on the behaviour of unsaturated silty sands under cyclic loading, with an emphasis on density changes and implications for maritime cargo transport. This study employs a combination of compaction methods and a shaking table test to investigate liquefaction, dynamic separation and densification under vertical cyclic loading. The effect of varying non-plastic fines content in the range of 10%–40% has been investigated. The wet shaking table tests resulted in fines migration and a layer of water forming on the soil surface, provided that the initial water content was sufficiently high. This simulates the process of dynamic separation, which has been identified as a possible cause of ship losses during maritime transport. The results also show that low initial degrees of saturation prevent this process from developing, at least in the small soil columns investigated. The study also provided evidence on the limitations of standard compaction procedures when fines contents exceed 10%.