| 摘要 |
PURPOSE:To realize a high-precision, durable and easy-to-execute measuring method by adjusting to a constant level a water level detector provided to a water level measuring pipe which is coupled with a reference water tank and installed at a position where measurement is to be taken, and by detecting the extent of ground subsidence by pouring a prescribed amount of water into the reference water tank for the measurement. CONSTITUTION:A water level measuring pipe 9 installed at a position where measurement is to be taken is linked to the bottom surface of a reference water tank 1 through a communication pipe 13. For the start of the measurement, an overflow pipe 2 is set to an intermediate level, and the tips of water level detectors 10 of water level pipes 9 are aligned and fixed. A drain cock 4 is opened to drop water in the reference water tank 1 and all of water level measuring pipes 8 into a spare tank 3. For the investigation of the state of ground subsidence, the cock 4 is closed to set the overflow pipe 2 to the lowest level, and the water is charged into the reference water tank 1 through a circulating pump 6. The water level is raised gradually and when the water level detector reaches the water level, a signal is sent to a monitoring device 12 through a transmission line 11. Thus, a high-precision, durable and easy-to-execute measuring method is obtained. |
