Study on strata behavior law of weak cohesive roof in deep buried fully mechanized top coal caving face

摘要

In view of the severe ground pressure behavior and spontaneous combustion risk of goaf in fully mechanized top coal caving face with deep buried weak cohesive roof and thick coal seam prone to spontaneous combustion, combined with theoretical analysis of mining overburden structure and field engineering practice, the structural characteristics of overburden rock and strata pressure behavior law are studied. The results show that: the deep buried thick coal seam fully mechanized top coal caving stope also has the phenomenon of surface step subsidence. Compared with the shallow coal seam, the surface subsidence is relatively slow, and the weak adhesion of the roof leads to the short periodic weighting step distance of the stope, and the average step distance is 9.9m. The measured peak value of advance abutment pressure is 7~10.5m in front of coal wall. According to the mine pressure control and fire prevention demand of goaf, the reasonable advancing speed is 4~5m/d.