The propulsion tube which is propelled with the propulsion mannered null propulsion jack which

摘要

PURPOSE: To efficiently excavate and jack the hard ground by providing an inner pipe reciprocatable by a jacking cylinder in an auger, and providing a striking hammer edge applying an impact to the tip section of the inner pipe with an air cylinder. ;CONSTITUTION: A ground jacking device is lowered in a starting vertical shaft, it is fixed by base fixing jacks 17, 18, and the reaction force generated when a jacking pipe 1 having a tip shoe 2 is jacked in the hard ground 22 is applied to the ground 21 by a base fixing jack 17 via a steel sheet pile 19. A jacking pipe 1 provided with the tip shoe 2 at the tip, an auger 4 fitted with a rotary roller type edge 10 at the tip, and an inner pipe 12 fitted with a striking hammer edge 11 driven by an air cylinder 16 at the tip on the inside are set. The soft ground is excavated by the rotary roller type edge 10, the striking hammer edge 11 is retreated than the rotary roller type edge 10 for a layer of bounding stones not so large, and the striking hammer edge 11 is advanced than the rotary roller type edge 10 face for relatively large boulders for efficient excavations.;COPYRIGHT: (C)1996,JPO