| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an underground probing apparatus, by which relative permittivity of natural ground being excavated at present can be found in an arbitrary excavating position, even if an object to be detected does not exist. SOLUTION: The underground probing apparatus is mounted on a tunnel excavator, which truns and drives a cutter head mounted at the front of a partition installed at the front part of a tunnel excavator body and which excavates an underground part, and it probes a foreign body, existing in the underground part in an excavating direction on the basis of reflected waves received by a front-probing antenna used to transmit and receive electromagnetic waves, with reference to the excavating direction. The underground probing apparatus is constituted to be provided with an antenna for a cutter chamber, which transmits and receives the electromagnetic waves, with reference to the inside of the chamber in the lower part of the chamber sandwiched between the cutter head and the partition and relative-permittivity computing means, by which the distance between a preliminarily given cutter head and the partition is compared with a measured distance between the cutter head, found on the basis of the electromagnetic waves received by the antenna for the chamber and the partition to find the relative permittivity and by which the relative permittivity used for a front-probing operation is corrected, on the basis of the found relative permittivity.</p> |
