| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect an underground buried article existing in front of a pipe jacking body accurately. SOLUTION: Transmitting and receiving antennas 16a, 16b are installed into a tapered front end section 9 with an inclined plane 10 in the drill head 5 of a pipe jacking body 2 propelling in soil 1, and a dielectric 15 consisting of a material having thickness increased towards the downstream side in the propulsive direction and having a dielectric constant higher than the dielectric constant of soil is arranged to the front section of these antennas. Electromagnetic waves from the transmitting antenna 16a are radiated into soil 1 in approximately parallel with the axis 11 of the drill head 5, and the reflected waves of an underground buried article 14 are received by the receiving antenna 16b or (16c).</p> |
