Improvement of soft clays by dynamic compaction with PVDs

Dynamic compaction method has been proven to be an efficient method to improve both the strength and deformation properties of cohesionless and unsaturated cohesive soil deposits. However, when used alone, this method is not effective on thick saturated soft clays. A modified dynamic compaction method, which combined the dynamic compaction and Prefabricated Vertical Drains (PVD) systems, was applied to improve the 2 to 6 m thick uncompacted colluvial fills over 6 to 9 m of soft marine clay sediment. The design and operation methods are introduced in this paper. Both laboratory and in-situ test results suggest this is an efficient method to treat the highly saturated soft clay soils. © 2004 ASCE.