Abstract: Saturated sand or silt is densified at depth by applying a radially propagated lateral translation force within a region of the soil, while water is actively withdrawn from such region toward the point of application of such force. A densification device incorporating the foregoing principle has a mechanism which imparts to the region surrounding the device cyclic lateral displacements which act axi-symmetrically to the longitudinal axis of the device; and, a filtered cavity and pumping mechanism for withdrawing water from the region surrounding the device.

Abstract: A method of constructing an underwater fill in a manner which enables the formation of a dense fill pile having steep side slopes and having an improved capability to resist erosion. The method comprises withdrawing water from fill deposited at an underwater construction site as fresh fill is added to the underwater fill pile.Apparatus for performing the method comprises a perforated conduit, pumping means for pumping water and a closed conduit for water communication between the perforated conduit and the pumping means. Operation of the pumping means withdraws water from underwater fill surrounding the perforated conduit for passage through the conduits and discharge from the pumping means.