| 摘要 |
PURPOSE:To enable a landslide sensor to surely respond to an external force in any direction with a high sensitiveness by containing the sensor helically coiled around a core bar in a pipe together with the core bar. CONSTITUTION:Since, when a pipe 3 around a sensor 1 inserted into the ground is subjected to, for example, a large bending due to the generation of a landslide, the sensor 1 in the pipe 3 is also subjected to the large bending, an alarm unit is operated by connecting the lead wire 1a of the sensor 1 to a power supply and the alarm unit in advance. Since the sensor 1 is helically coiled around a core bar 2, even if the circumferential position of the pipe 3 is subjected to any change in inserting the sensor 1 into the ground, the alarm unit can be always surely operated. Further, since the sensor 1 is subjected to a compressive deformation sufficient to operate the alarm unit at least in a portion wherein the inner circumferential surface of the pipe 3 most closely approaches to the core bar 2, even when the core bar 2 and the sensor 1 are subjected to no or little bending deformation, a landslide can be detected with an excellent sensitiveness. |
