Abstract: Hedong coal mine in Shanxi is among large ones in China and has a very complex geological structure.In-situ stress measurement for the mine depth was required for studying the stress variation.The in-situ stress measurement was made by stress relief method with improved CSIRO cells.New temperature correction technology was used in studying the effect of temperature on the measurement accuracy, the effect of resin elastic modulus and the strain gauge location were also considered, and the formula for correcting the confining pressure was deduced, improving the accuracy of in-situ stress measurement.The measurement results show that the maximum principal stress is nearly horizontal in NNW direction and of the magnitude of about 14 MPa.In the same plane, a kind of in-situ stress has some but not significant change in both magnitude and direction at different points, indicating a uniform in-situ stress field in the mining area.

Key words: In-suit measurement, CSIRO cells, Stress relief method, Rock, Elastic modulus