UNDERGROUND DISPLACEMENT GAUGE AND UNDERGROUND DISPLACEMENT CALCULATION METHOD

摘要

To provide an underground displacement gauge and a natural ground displacement measurement method with which it is possible to measure a displacement in the horizontal and vertical directions occurring to a natural ground ahead of a pit face due to tunnel excavation at the same measurement point.SOLUTION: Provided is an underground displacement gauge for measuring an underground displacement and installed in a hole drilled in the underground, comprising: a plurality of long-sized members arranged in series; a plurality of joint members for connecting the adjacent long-sized members together; and two measurement units accommodated in the joint members and provided on plate surface with a strain causing plate in which a strain sensor is installed. The joint members include a pair of joint sleeves arranged in series and connected to the ends of the long-sized members and a hollow cylindrical substance arranged between the pair of joint sleeves and connected so as to be rotationally move in a direction in which the joint sleeves cross each other, with two of the measurement units installed inside of the hollow cylindrical substance in parallel across the pair of joint sleeves toward directions crossing the plate surface of the strain causing plate each other.SELECTED DRAWING: Figure 2