| 摘要 |
<p>PURPOSE:To search the embedded place of a pipeline with high accuracy by preventing the movement of a marker (marking body) due to the charge of earth and soil at the time of back-filling, by constructing an embedding pipeline of a tubular body having the marker formed into a ring shape externally fitted thereto. CONSTITUTION:A marker 1 is constituted by hermetically sealing a searching signal responding means 2 in a case 101 formed into a ring shape and the inner diameter of the through-hole 102 thereof is set to a size almost equal to or slightly larger than the outer diameter of a tubular body 3 to which the marker 1 is externally fitted. The searching signal responding means is constituted, for example, of a quartz resonance circuit wherein a coil, a capacitor and a quartz vibrator are connected in parallel. Then, the tubular bodies 3 having a required number of the markers 1... externally fitted thereto are successively laid in the ditch formed in the ground (road) to be mutually connected by joints 4 and covered with earth and sand to construct an embedded pipeline. By this method, since the ring-shaped marker is externally fitted to the tubular body, the marker is not moved by the charging of earth and soil at the time of back- filling or the variation of soil after the back-filling.</p> |
