Abstract: Liquefiable soil is treated for earthquake liquefaction protection prior to erecting a building structure or work. A plurality of substantially vertical prefabricated drains are positioned at spaced intervals in the liquefiable soil and a reservoir is provided and adapted for draining off water which is expelled from the drains during an earthquake. The drains are generally comprised of an elongated plastic core material providing channels for channeling water off or therealong and this core is sometimes or selectively surrounded by a filter fabric as required to provide a composite drain.

Abstract: Apparatus for inserting prefabricated drain members downwardly into underlying earth which includes a vertically extending mast that supports an elongated earth penetrating mandrel. The mandrel is adapted to receive a prefabricated drain member for movement with the mandrel down into the earth to insert drain members. A drive is mounted on the mast for driving the mandrel into and out of the underlying earth and the drive includes a rotary drive gear that engages the mandrel and a motor for driving the gear. A vibrator is mounted on the upper end of the mandrel for imparting vibrations to assist in its penetration into the earth. A flexible torsion drive coupler couples the motor to the drive gear for driving the drive gear and for also isolating the motor and the mast from vibrations imparted to the mandrel by the vibrator.

Abstract: Apparatus for inserting an elongated flexible prefabricated vertical (PV) drain downwardly into the earth. The apparatus includes a vertical mast having a lower standard mast base and a lightweight extra long mast extension. A vehicle supports the mast from its mast base in order to raise and lower the mast to and from vertical and to otherwise manipulate and transport the mast in a conventional manner. A longitudinal chamber extends for the entire length of the mast and carries therein an earth penetrating tube for vertical movement. This earth penetrating tube also has a passage therethrough for receiving the elongated flexible PV drain for movement with this insertion tube down into the earth when driven therein. The mast extension includes a series of axially aligned extension tubes constructed of light weight material and removably connected together end to end, and a combination spar and guy mechanism is utilized for supporting this long mast extension from the relatively short mast base.

Abstract: Compacted granular or stone columns are constructed in soil to increase the load-bearing capacities of the native soil. An elongated hollow tubular member is penetrated down into the soil to a predetermined depth and then the granular material or stone for constructing the column is fed down through this member and out the lower end thereof where it is then driven outwardly in a radial direction by an impeller which is exposed, at least in part, at the lower end of the tubular member, as the hollow tubular member is either penetrating or being withdrawn from the soil at a predetermined rate to thereby forceably compact this granular or stone material in a substantially radial direction to construct a stone column. Sufficient forces may be applied by the impeller to the granular or stone material to fracture the surrounding soil.