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.