| 摘要 |
Method for thrusting a shield for use in tunneling includes the steps of causing a rotary head, provided at the front portion of a shield body, an eccentric motion so that earth, soil or sand covering the front of the shield is pressed away radially of the shield, and exerting a thrust on the shield body during the eccentric motion of said rotary head. Apparatus for carrying out the method includes a driven crank shaft or a driven eccentric straight shaft, a conical or frustoconical rotary head supported rotatably by the crank or eccentric straight shaft, conveyor for discharging mined material backwardly, and hydraulic jacks for imparting a thrust to the shield body. |
