Optimization and Research on Mining Process in Coal Mines under Complex Geological Conditions

Aiming at the problems of low mining efficiency, insufficient stoping rate and others under complex geological conditions in Guojiawa Coal Mine, based on the dynamic support theory (dynamically adjusting support parameters through time series monitoring of surrounding rock deformation) and multi-field coupling control method (stress field-seepage field-gas field collabrative regulation and control), a full chain optimization scheme is proposed. The dynamic support theory guides the 18° oblique intersection working face layout and the graded support system: anchor rods with 120 kN pre-tightening force are adopted in conventional areas, and 8.5 m yielding anchor cables are applied in fractured zones, a closed loop of "monitoring-evaluation-regulation and control" is formed; The multi-field coupling method drives the combination use of "U+L" type ventilation system and directional grouting technology, the time number of gas exceedances is reduced by 88.9%. The synergistic effect of key technologies is significant: the reduction of fault exposure length reduces coal pillar loss, and the stoping rate is improved to 84.3% combined with the three-dimensional extraction network (with a main hole spacing of 6.8 m); The intelligent group control of shearer-hydraulic support-scraper conveyor (cutting power 1250 kW+bracket resistance 4800 kN) promotes a 44% improvement in daily pushing progress to 6.2 m/d, the cost per ton of coal is decreased by 18.3%, and safe and efficient mining is achieved ultimately.