| 摘要 |
<p>PURPOSE:To enable survey around a pipe line regardless of the state of reinforcement disposed at a buried pipe by setting plural survey areas along the periphery of the buried pipe, and using a survey instrument provided with an underground survey radar as well as with a drilling means at the tip. CONSTITUTION:A survey instrument 3 is inserted into a manhole 15a, and a drilling means 4 is corresponded to one of survey areas. Superhigh pressure water is generated by a pump 16 and jetted from the nozzle 4a of the drilling means 4 to start drilling. The survey instrument 3 is advanced along the longitudinal direction of a pipe 1 while rotating a survey means 5 and the drilling means 4 and also transmitting by transmitting antenna 9a of a radar simultaneously, and the echoes of radiated electromagnetic waves are received by an antenna 9b. This receive signal is transmitted to a control element 8 where the signal is processed, and the state of the underground, that is, the direction and distance of a pipe 18, is displayed on a display 8a to enable the survey. The existence and direction-distance of the pipes 17, 18 or other obstacles can be thereby detected by monitoring the display 8a.</p> |
