| 摘要 |
PURPOSE:To detect the tip position of the propulsion tube easily with high precision by receiving acoustic wave signals from transmitters in longitudinal holes bored in the ground surface successively by a receiver provided to the tip of the propulsion tube, and detecting the position of the receiver from the arrival time of the signals. CONSTITUTION:A mud shield type drilling machine 8 is connected to the tip part of the propulsion tube 1 which is propelled in the ground under a road 7 with a bottom pressing jack 6 in an originating pit 5. The receiver 2 is fixed to the upper part of the steel-made cylindrical main body 16 of the drilling machine 8. Three longitudinal holes 20A-20C are bored in the ground at one side part of the road 7 at intervals in the lengthwise direction of the road and three longitudinal holes 20D-20F are also bored in the ground at the other side. Transmitters 21A-21F are put in the respective longitudinal holes 20A-20F and water or mud 22 is injected, and the respective transmitters are connected to the transmission part of a transmitter 23 installed on the ground. Further, the receiver 2 is connected to a signal processor 24 through a cable 25 for reception. |
