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.

Abstract: A novel method of injecting a back filling injection material employed in a shield-forming process is described herein. A screw type injection pump with a hopper connected to its intake port is utilized. This pump is rotated in a reverse direction to intake a back filling material into said hopper through a delivery hose connected to its delivery port. The upper limit pressure and a lower limit pressure for the injection pump are set for injection of the back filling material. The injection pump is next rotated in its normal direction to inject the back filling material to a desired location through the delivery hose, and then, after completion of the injection filling of the back filling material, the injection pump is rotated in a reversed direction again to intake water through the delivery hose, thereby washing of the hose and the injection pump can be effected.

Abstract: Shield tunneling machine and method which may minimize the variation in water- and earth-pressure at the tunneling face so as to hold the ground firm and to ensure the safe tunneling.