ODD-FORM CROSS SECTION TUNNEL EXCAVATOR AND ODD-FORM CROSS SECTION TUNNEL EXCAVATING METHOD

• Main Authors: NAKANE TAKASHI, YOSHIDA YUZURU, OSAKA MAMORU, FUJITANI TOSHIMI
• Format: Patent
• Language: English
• Published: 13.01.2011
• Subjects: EARTH DRILLING; FIXED CONSTRUCTIONS; GALLERIES; LARGE UNDERGROUND CHAMBERS; MINING; SHAFTS; TUNNELS

PROBLEM TO BE SOLVED: To provide an odd-form cross section tunnel excavator and an excavation method which can control fluctuations in soil pressure associated with the coming-out and withdrawal of an extendable cutter by a simple constitution and which can reduce costs.SOLUTION: The extendable cutter 6 is provided at one end of a moving body 13, and a piston 29 is provided at the other end of the moving body 13, which is provided to a cutter frame 5 and which makes a reciprocating movement. A cylinder 30 provided to the cutter frame 5 stores the piston 29, and one end of the cylinder 30 is opened. When the odd-form cross section tunnel is excavated by moving the moving body 13 in a reciprocating state while rotating or rocking the cutter frame 5, the soil pressure which increases when the extendable cutter 6 is moved in the projected direction is absorbed by guiding the earth and sand into a soil-pressure absorption chamber 31 by the movement of the piston 29 to the depth side of the cylinder 30. The soil pressure which decreases when the extendable cutter 6 is moved in the withdrawal direction is supplemented by discharging the earth and sand from the soil-pressure absorption chamber 31 by the movement of the piston 29 to the opening side of the cylinder 30. Thus, fluctuations in soil pressure are controlled.