Abstract: A method of lifting and stabilizing a concrete slab having an opening therein in which a plate is attached to the top surface of the slab, the plate having an opening coinciding with the opening in the slab, a hydraulic jack having a downwardly extending piston is removeably secured to the plate and a series of tubular shafts are forced downwardly through the opening in the plate and the slab to penetrate the earth beneath the slab and apply lifting force. When the slab has been lifted to the desired elevation, grout, such as a concrete slurry, can be injected below the slab so that the slab is stabilized in the selected elevational position. After the plate is removed the hole in the slab is filled.

Abstract: Apparatus for shoring a concrete slab, for example, comprising support members engageable with the bottom of the slab, a guide engageable with the support members having an internal screw thread, and piling having an external screw thread which mates with the internal screw thread of the guide. The piling is rotated about a generally vertical axis for threading it down through the guide into the ground below the slab and into engagement with load-bearing underground strata thereby to shore the slab. A method of this invention for shoring a slab is also disclosed.

Abstract: A method of installing a pile beneath the foundations of a building comprises forming a hole, preferably at a small angle to the vertical, through the foundation driving a first pile casing section through said hole into the ground beneath the foundation with a percussive machine located at or near floor or ground level of the building, applying to the end of the first pile casing section a further pile casing section and driving the composite pile casing into the ground by a percussive machine located no lower than the floor or ground level of the building, fitting a further percussive machine having a maximum external diameter no greater than the maximum external diameter of the foundation hole and driving said casing further into the ground with said further percussive machine following the casing into the ground, completing said further driving operation before said further percussive machine penetrates completely below floor or ground level, withdrawing said further percussive machine and thereafter inse

Abstract: A system for pier underpinning of settling foundations, wherein each pier comprises a column of pipe sections perpendicularly arranged downwardly aligned directly beneath the foundation footing, in the vicinity of its settling, the column extending into contact with the earth's bedrock, the column being fomed by a series of said pipe sections having sufficient internal diameter to accept a supply of concrete during the formation of a cap upon the upwardly disposed pipe section, a mechanical jack arranged immediate the underside of the footing and the top of the concrete cap and tightened therebetween, to support the footing thereon, and a supply of concrete forming a concrete support around the emplaced jack and upon the formed cap for forming a complete pier for adding support to the foundation and its footing; and a method of forming the pier, a hydraulic jack is used for driving the pipe sections into the ground, until bedrock is encountered, and then said hydraulic jack is removed for replacement by the m

Abstract: Roofs of underground excavations are supported by forming sheet-material elements into tubes whose diameter can be varied by changing the overlap between the longitudinal edges of the rolled-up sheet material, standing the tubes upright to bear against the roof and the floor of the excavation, and filling them with hardenable material in flowable condition which, after hardening, will form a roof-supporting column.