| 摘要 |
PROBLEM TO BE SOLVED: To carry out smooth propulsion by preventing excavation residue by a cutter on the front of a shell frame in the excavation of a gallery or a drilled hole having an approximately square-shaped sectional form. SOLUTION: When operating rods for hydraulic jacks 133, 133 in left-right cutter driving devices 13, 13 conduct projecting-retreating operation, cutter arms 131, 131 are rocked in the horizontal direction centering around support shafts 132, 132, rod-shaped cutters 12, 12 installed at the outer end sections of the cutter arms 131, 131 are reciprocated and moved so as to draw arcuate surface-shaped loci at the front places of the front plate 111 of a shell frame 11, and a ground G in the whole region of the front of the front plate 111 is excavated. Accordingly, excavated materials generated are taken into a chamber 15 through soil-sand intake holes 111b and slits 111a bored to the front plate 111, mixed with a sludge preparation material supplied from a sludge feed pipe 16, and carried out onto the ground through a sludge withdrawal pipe 17. |
