Anelastic strain recovery in situ stress measurement method and its application prospect in underground mines

Abstract

Current stress state data are important in underground mine construction, analysis the of tunnel stability, the forecasting of coal and gas rock bursts in underground mines. At present, the hollow inclusion gauge is primarily used for in situ stress measurement in underground mines. However, the sensors of these gauges often fail to fully adhere to the borehole wall, which can reduce the reliability of the measurement results. In this study, the anelastic strain recovery (ASR) in situ stress measurement method based on oriented cores is introduced. The effectiveness of this technique is analyzed by comparing the test results with those obtained by the hydraulic fracturing method. In addition, the reliability of the ASR method is evaluated by repeatability testing. The ASR results indicate a horizontal minimum principal stress error of less than 10% compared with those obtained by the hydraulic fracturing method. The repeatability test results show good consistency in the in situ stress measurement results of two back-to-back test samples. The ASR method is a safe and highly efficient technique that is not limited by the depth and measurement environment. Therefore, it is expected to have broad application for underground mine in situ stress measurement.