Evaluation Of Disaster Formation Conditions And Spatiotemporal Prevention And Control Mechanism For Composite Dynamic Disasters In Working Face

With the increasingly complex mining conditions of mine working faces,refined analysis and evaluation of working face disaster formation conditions,targeted preventive measures,and real-time monitoring and early warning have become normal demands.In order to improve the pre-disaster and disaster prevention capability of the working face,and to reduce the degree of potential hazard of compound dynamic hazards formed in the working face due to the influence of multiple disaster formation conditions,through the analysis and research in this thesis,the conditions for the occurrence of compound dynamic hazards at the working face are clearly grasped,and the hazard areas of different levels are integrated and divided to form a spatial grid.According to the actual situation of the working face,use the layered water injection scheme with strong practicability and good economic effect to control,and a variety of monitoring and early warning means are used to monitor in real time,eventually forming a spatio-temporal prevention and control mechanism to lay the foundation for the safe recovery of the working face.The index of bursting liability of coal and basic gas parameters are measured through the laboratory,and it is determined that the coal seam has a weak impact tendency and no outburst risk,focusing on considering the abnormal gas gushing area caused by geological structure in the process of encircling the working face;the working surface is analyzed and evaluated by impact pressure disaster formation conditions,4 medium risk areas are divided,the gas abnormal gushing disaster formation condition is evaluated,one medium risk area is divided,and the different levels of risk areas of the working surface are clarified by multifactor coupling method,and finally 6 different levels of danger areas are divided;the overlying rock movement during recovery is analyzed and studied through numerical simulations and the actual mining conditions of the adjacent workings,and a working face cycle pressure step of 20-30m was determined.Through the four types of indicators of the coal seam water injection judgment criterion,the 16#coal seam is determined to be a water-fillable coal seam,and the best coal seam water injection scheme is selected to calculate the single-hole water injection water consumption of Q=123m~3,and the recovery time of the advanced working surface of the water injection hole is10 days;the coal seam residual gas content q and the average value of water content increaseΔH are used to test the effect of water injection in the coal body,and the overall drill chip volume decreased by an average of 2kg·m-1 compared to before water injection.The PASAT-M portable microseismic detection instrument is used to scan the 5 key areas delineated,and the KJ551 microseismic monitoring system is installed at the working face to classify the working face power hazard level into 2 levels,using microseismic monitoring for real-time early warning and spatial early warning of drill chip volume to form a spatial and temporal prevention and control mechanism for compound power hazards at the working face.