Abstract: An improved grout impregnation method which uses an injection tube for contacting and mixing different kinds of materials supplied thereinto separately to prepare a grout and impregnates the grout into the earth through an injecting opening provided at a tip end of the tube.

Abstract: In a cooling zone of a continuous annealing line engineered to continuously process longitudinally travelling steel strip, the strip is first slowly cooled to a desired temperature at a rate of not higher than 20.degree. C./sec. by means of a jet stream of cooling gas ejected against the surface of the strip and subsequently quenched to a desired temperature at a rate of not lower than 70.degree. C./sec. Thinner strip is quenched by high-speed gas-jet cooling that is effected by ejecting a jet stream of cooling gas against its surface, while heavier strip is quenched by bringing it into contact with the perimeter of cooling rolls cooled by a coolant. Namely, quenching is achieved either by high-speed gas-jet cooling or roll cooling depending on the thickness of the strip being processed.

Abstract: A grout injection method and apparatus, characterized in that a grout comprised of two liquids and curable when the two liquids are combined are supplied, in a grout injection operation, to an injection pump, introduced through separate passages formed concentrically in the pipe, respectively, into an annular chamber formed within the pipe, and uniformly combined, contacted and mixed with each other in the annular mixing chamber before injection into the soil. The passages of the liquids communicating with the annular mixing chamber are blocked when the grout injection is not carried out.

Abstract: A method of injecting grout into soil using a combined injection and boring rod wherein the rod comprises a tip and at least one injection nozzle at the lowermost end thereof. A sleeve packer of an elastomeric material is embedded in a recess in the periphery of the rod along the length thereof. A plurality of passages extend in and along the rod, the passages being defined by at least two parallel inner tubes spaced within an outer tube, and further by the spacing between the outer tube and the inner tubes. The method includes the steps of inflating the sleeve packer by introducing fluid pressure into the recess through a hole in the outer tube communicating with one of the passages, feeding two liquids of curable grout through respective passages and mixing the two liquids within the rod at the tip of the rod, and then injecting the mixed grout into the soil from the injecting nozzle.