Study On Ground Pressure Characteristics And Trough Supports In Comprehensive Mining Activity For Contiguous Coal Seams

This study is for the mechanized mining activity of the lower contiguous coal seam in Nanyangpo Coal Mine.The coal seam is characterized by gravel strata,disintegrable roofs,peeling walls,and instable tunnels.The thesis employed the methods of theoretical reasoning,quantitative mechanic analysis and in-situ monitoring experiments to examine the detrimental motion,ground pressure and coal face stability in lower seam caused by upper seam exploitation.The results reveal the mechanism of roof rock degradation and proposed the controlling measures against roof falling and wall peeling accident.According to the characteristics of trough stability in lower coal seam affected by the of upper coal seam exploitation,the mechanism for lower-seam unbalance was obtained,and the control methods and measures were put forward for the corresponding geological characteristics.The experimental results were verified and the effectiveness were tested for the measures for maintaining coal face stability and controlling trough area.The in-situ monitoring demonstrates that the optimized tunnel supporting scheme resulted in the effective control in rock deformation and the supporting force of the props was within the allowable range,indicating the safety of recovery mining roadways.Such application indicates the feasibility of the optimized tunnel supporting scheme and readiness for being used in mining field.