Analysis of mining stress concentration area based on deep coal body stress monitoring

At present, the coal body stress monitoring position is single and fixed, resulting in the lack of diversity of coal body stress monitoring data. In order to obtain the deep coal body stress data during mining and the range of deep coal body stress concentration area under the influence of mining, 7303 working face of Zhaolou Coal Mine is taken as the engineering test site. The deep stress data under the influence of mining are obtained by placing deep stress monitoring points in two parallel grooves on the working face. Meanwhile, the stress concentration range of deep coal stress during the process of mining influence is analyzed and studied through laboratory installation performance test of deep stress monitoring borehole stress meter, FLAC^3D numerical simulation, and comparative analysis of field passive CT inversion. The following conclusions are drawn: the value rule of deep stress monitoring compensation coefficient K is obtained. K is 1.02 when 20 m is monitored, 1.03 when 30 m is monitored, 1.05 when 50 m is monitored, and 1.07 when 70 m is monitored. The numerical simulation analysis shows that, based on the rock mechanics parameters of Zhaolou Coal Mine, under the influence of mining, the peak stress monitoring position of deep coal body is 20-30 m, and the peak stress reaches about 25 m, and the peak stress is about 23.6 MPa. With the increase of monitoring depth, the vertical stress gradually decreases. Based on the passive CT inversion data and the analysis of the in-situ measured deep stress monitoring data, it is concluded that the measuring point arranged in the 20 m deep stress monitoring range can better reflect the stress change of coal body under the influence of mining.