套孔应力解除法与声发射法在新城矿区深部地应力测量中的对比研究

Comparative Study of Stress Relief Method and Acoustic Emission Method in In-situ Stress Measurement in Deep Area of Xincheng Gold Mine

为得到新城金矿深部区域的准确地应力分布,分别采用应力解除法和声发射法对该矿区深部进行了地应力测试,得到了不同测量方式下深部地应力的分布规律。采用定向扰动最小二乘法多元回归来提高套孔应力解除法的6个应力分量的求解精度,并采用空间坐标变换公式和LUT-str三维地应力计算程序对地应力大小和方向进行了计算。使用应力解除法测量了-830^-1 030 m之间4个水平6个测点的地应力,使用声发射法测量了-950^-1 150 m之间3个水平3个测点的地应力,计算得到相应的地应力及其分布规律。2种方法测量结果对比表明:深部地应力以水平应力为主,最大水平主应力为NWW-SEE向,二者测得的最大水平主应力、垂直主应力和最小水平主应力具有较好的一致性。

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.