| 摘要 |
PURPOSE:To reduce the occurrence of trouble such as subsidence, depression, the collapse of a working face or the like, and also to extend the range of application of the method, and further to reduce labor by enabling the stable control of the working face to be securely carried out even under a high hydraulic pressure. CONSTITUTION:The earth pressure inside the chamber 4 of a shield excavator 1 is measured by an earth-pressure gage 5, and the deviation of the measured earth pressure from a target value is obtained, and the driving speed of a force feed pump 6 that has been connected to a screw conveyor 3 is controlled in accordance with the deviation while turning the screw conveyor 3 at a constant speed for regulating the amount of forcedly discharging earth per unit time, consequently the earth pressure on the working face can be controlled. The screw conveyor 3 also functions as a damper for reducing the pressure fluctuation due to the pumping of the force feed pump 6. |
