| 摘要 |
PROBLEM TO BE SOLVED: To easily and precisely measure a direction and a level of a stress acting on a ground in a periphery of a cavity. SOLUTION: This method and this instrument are shown hereinafter. In the ground stress measuring method, (1) a boring hole is drilled from a wall face to measure the ground stress in the periphery of the cavity, (2) then a laser type displacement sensor is inserted into the hole, (3) the displacement sensor is rotated thereafter to measure a cross-sectional shape of the hole, and (4) the ground stress in the periphery of the cavity is found based on a measured distortion amount of the cross-sectional shape of the hole. The ground stress measuring instrument is constituted of (1) the laser type displacement sensor having an outside diameter allowing insertion into the boring hole and for detecting the displacement of a hole wall, (2) a motor for rotating the sensor, (3) a support strut for fixing the sensor and the motor and inserted into the hole, (4) a foundation part for fixing the instrument including the strut in a measuring portion of the boring hole formed in the measured ground, and (5) a storage/computation part for storing and/or computing a measured result. COPYRIGHT: (C)2004,JPO
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