Abstract:

As the mining depth increases，the ground stress gradually increases，and rock burst phenomenon is likely to occur，which brings great damage to underground roadways and stope.Accurate ground stress magnitude and direction has good reference guidance value to underground engineering and can effectively avoid the occurrence of damage such as rock burst.In order to obtain the accurate ground stress distribution in the deep mining area of Xincheng gold mine，the stress relief method and acoustic emission method were used to measure the in-situ stress of the -830~-1 150 m deep mining area.The specific method of geostress measurement and the solution process of geostress measurement results were expounded.Subsequently，six measurement points of -830 m，-930 m and -1 030 m were measured using the stress relaxation method，and three measuring points in the three levels of -950 m，-1 050 m and -1 150 m were measured by AE method.Among them，the directional disturbance least squares multiple regression was used to improve the accuracy of the six stress components of the hole stress relief method，and the coordinates of the strain gauge were transformed into a space rectangular coordinate system by using the space coordinate transformation formula.The magnitude and direction of the ground stress were calculated by using the LUT-str three-dimensional geostress calculation program.The distribution law of the deep ground stress in the mining area under two different measurement modes was obtained，and the comparative analysis of the measurement results of the two methods were carried out.The results of the two measurement methods show that the horizontal principal stress and the vertical principal stress measured by the two measurement methods both increase linearly，the vertical principal stress is both close to the self-heavy stress of the overburden layer，and the deep stress of the Xincheng gold deposit is horizontal stress mainly，the maximum horizontal principal stress is NWW-SEE direction.The maximum horizontal principal stress measured by AE method is about 1.39 times of self-weight stress，and the stress relieving method is about 1.49 times.The maximum horizontal principal stress.vertical principal stress and horizontal minimum principal stress measured at -1 030 m level with errors of 12.1%，5.35%，and 13.46%，respectively，which have good consistency and provide good support for the exploitation and support design of deep mining areas.

Key words: stress relief method, acoustic emission method, deep mining area, in-situ stress, least square method, LUT-str