矿山巷道矿压数值模拟推演及监测技术研究.

In order to further master the tunneling technology ol mining small coal pillars along the gob and improve the resource recovery rate. According to the specific production geological conditions, this paper analyzes the distribution characteristics and inlluence ol small coal pillar support stress in small coal pillar roadway excavation, working lace advance and secondary mining by means ol ground pressure monitoring and numerical simulation. The results show that: 1)During roadway excavation, the pressure in the first 50 meters ol the roadway is large, especially the two sides of the roadway move closer, and the maximum distance ol the two sides is about 200 mm. 2) During the roadway excavation stage and the mining inlluence period, a 5 m coal pillar is lelt between the return air chute and the upper transportation chute, lorming a large stress concentrathe maximum vertical stress in the coal pillar is 21. 38 MPa. The vertical stress in the coal wall behind the Iront of the work is about 30 MPa, the stress concentration lactor is about 3, the inlluence range is about 84 m, and the maximum vertical stress ol the coal pillar is 41 MPa. 3) Allected by the secondary mining, the stress in the coal pillar is basically about 40 MPa, which changes little compared with the primary mining, while the peak stress appears in the triangle area in Iront ol the working lace, up to 57. 4 MPa, indicating that this area is the locus ol prevention and control during the mining ol the working face. The results of ground pressure monitoring and numerical simulation are relatively consistent, which further proved the reliability ol the research results. [ABSTRACT FROM AUTHOR]