| 摘要 |
<p>The method inserts a building component in or extracts it from the ground. A vibrator unit transmits to the component while it is thrust downwards or pulled upwards. At the same time, a second vibrator unit generates vibrations in the ground which are in anti-phase with those caused by the first vibrator. Vibration can be transmitted to the ground via a second component inserted or extracted at the same time, the components being close together.</p> |
