| 摘要 |
<p>PURPOSE:To obtain a wide range of ground information quickly at a face by selecting a detection signal with a frequency thereof coinciding with a frequency of current from detection signals of a voltage based on currents varied in frequency flowing from a plurality of points in a circumferential direction of a shield excavator. CONSTITUTION:A plurality of electrode trains 14a-14c are mounted on a front skin plate 14 of a shield excavator 10 and the electrode trains 14a-14c are arranged at an equal angular interval with respect to the center of a excavator 10 and the electrode train 4b is positioned at the top thereof 10. The electrode train 14a-14c each comprise an energizing electrode to feed a current to a mud 15 in the perimeter of the excavator 10 and a ground 17 and a detecting electrode to detect a voltage based on the current and are arranged on an insulating body 16 fixed on the skin plate 12 at an equal interval. With such an arrangement, currents varied in frequency flow to the mud 15 and a detection signal alone the same in frequency as the current among those obtained with the detecting electrode is selected to be inputted into a signal processor 22.</p> |
