GROUND STRESS SENSOR AND EARTH PRESSURE DETECTION DEVICE

PROBLEM TO BE SOLVED: To provide a ground stress sensor that can sensitively detect slight change of earth pressure, is easy to handle in a measurement site, and can reduce measurement cost.SOLUTION: The ground stress sensor includes: a measurement body part 2 that can be inserted toward the underground from a ground surface G; a cantilever support part 3 that can be inserted toward the underground from the ground surface and whose one side is fixed to the measurement body part 2 and that is elastically deformable to the measurement body part 2 by external force P received from the underground side; a thin wall part 3b that is formed on the support end side of the measurement body part 2 in the cantilever support part 3 and formed so as to be thinner than the thickness of the free end side in the cantilever support part 3; and a strain gauge 5 that is fixed to the thin wall part 3b, and electrically detects strain of the thin wall part 3b, the strain arising when the cantilever support part 3 is elastically deformed by the external force P. 【課題】 土圧の僅かな変化を敏感に捉えることができ、しかも計測現場での取扱いが容易で、かつ計測コストを低減することが可能な地盤応力センサを提供する。【解決手段】 地表Ｇから地中に向けて挿入可能な計測本体部２と、地表Ｇから地中に向けて挿入可能で一方が計測本体部２に固定され地中側から受ける外力Ｐによって計測本体部２に対して弾性変形可能な片持支持部３と、片持支持部３における計測本体部２の支持端側に形成され片持支持部３における自由端側の厚みよりも薄く形成された薄肉部３ｂと、薄肉部３ｂに固定され外力Ｐによる片持支持部３が弾性変形する際の薄肉部３ｂのひずみを電気的に検出するひずみゲージ５とを備える。【選択図】 図１