Bearing characteristics and mine pressure behavior of wide coal pillars facing mining
In order to solve the problem of tight mining succession in single wing mining mines,there is often a situation of opposite excavation.During the excavation,determining the law of strata behaviors and the width of coal pillars is the key to roadway excavation and safe recovery.We took the 100303 transportation roadway of Tanyaoping Coal Mine as the engineering background,and used theoretical analysis,numerical simulation,on-site monitoring and other methods to study the reasonable width of the coal pillar and the law of strata behaviors during the excavation period.According to the theoretical calculations,under the dual influence of excavation disturbance and mining on the working face,it is ensured that the coal pillar does not completely undergo plastic failure and has an elastic core width of at least 30 m.According to the numerical simulations,when the heading face reaches 20-30 m in front of the meeting position,the surrounding rock deformation begins to increase,and the deformation of the coal pillar and mining sides both exceed 0.5 m;When the excavation reaches a certain distance behind the goaf,the surrounding rock deformation accelerates due to the combined influence of excavation disturbance and side abutment pressure in the goaf,resulting in severe deformation of the coal pillar wall,the maximum deformation is over 1 m.So,it's proposed when the excavation distance of the 100303 transportation roadway is 70 m from the 100302 fully mechanized mining face,the excavation should be stopped,and the support parameters should be optimized within the disturbance range to improve the bearing capacity of the coal pillar.On-site monitoring showed that,the deformation of the roof,floor,and two sides of the roadway was small and within a controllable range,the surrounding rock deformation was controlled.
excavation toward miningcoal pillar widthstrata behaviorsnumerical simulationsurrounding rock control
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