Core Orientation Technology Based on Drilling Trajectory Projection and Its Application in In Situ Stress Measurement of the Deepest Shaft in China

Deep borehole cores are an important material basis for understanding deep stress conditions and rockburst risk; however, the complex environment of boreholes poses many challenges to traditional core orientation techniques, thus limiting application in fields such as situ measurement. A technical method restoring original spatial attitude nonoriented geological on ground was proposed based inherent “trajectory projection consistency” relationship between corresponding core. prototype machine reorientation developed. Using this machine, performed drilled from deepest shaft China. Subsequently, reoriented acoustic emission (AE) conducted identify within project area. Meanwhile, measurement accuracy verified by relief method. The results show that distributions, including azimuth trends principal stresses two methods, good agreement indicate historical maximum case mine has little abrupt variability with present day. research can be used design safe construction shaft.