RELATIONSHIP OF MEASURED VALUES OF STRESS RELIEF METHOD OF EMBEDDED STRAIN GAUGE AND INITIAL STRESS FIELD
CHEN Qu1，WU Dezheng2，XU Jiang3，MIZUTA Yoshiaki1，4
(1. 3D Geoscience，Inc.，Tokyo 107–0052，Japan；2. Tiandi Science and Technology Co.，Ltd.，Beijing 100013，China； 3. State Key Laboratory of Coal Mine Disaster Dynamics and Control，Chongqing University，Chongqing 400044，China； 4. Faculty of Engineering Yamaguchi University，Yamaguchi 755–8611，Japan)
Abstract：In the rock stress measurement with stress relief method of embedded strain gauge，both the size of core diameter and the packed thickness of elastic mortar affect the accuracy of measuring precision. In order to discuss the issue，the authors analyzed three cases of stress relief method of embedded strain gauge in secondary stress field，which are over-coring model，practical sensitivity test model and theoretical sensitivity test model. By the comparison of the exact solutions of three cases and calculation of two measurement systems，it could be found that the packing core diameter is not large enough，then measured values of ground stress of rock mass will be significantly underestimated compared with the actual stress field.
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2012, Vol. 31 
