摘要 |
PURPOSE:To give flowability and cut-off efficiency to excavated earth in an earth pressure room and a screw conveyor with a simple equipment without using sediment making materials such as bentonite, etc., to make it possible to easily drive a tunnel and, at the same time, to enable the pressure-feed, treatment of discharged earth. CONSTITUTION:In a method to excavate earth by using a shield excavator 10 separately forming an earth pressure room 16 backward of a shield cutter 12, additive dissolving methyl cellulose in water is sent to a foaming apparatus 28 together with compressed air from a compressor 24 to form in the shape of a bubble. It is injected to the inside of the earth pressure room 16 to drive forward while mixing it with excavated earth. |