Comprehensive Treatment Research On Isolated Working Face Under Certain Conditions Of Close Distance Coal Seams And Little Coal Pillar

The problem of gas management is the nightmare and always perplex coal mine safety production, moreover the difficulty of isolated working face gas management became more hard because of its particularity; Along with the stopping mining of1201working face and1203working face, the1202isolated working face was forming step by step. Arm at the problem of upper corner and ventilation roadway’s gas concentration ultra-limit when1202isolated working face during the process of mining, and in order to solve the technology problem of working face safety production, the paper adopt some research ways like theory analysis、numerical simulation、engineering practice to analyze problem and solve problem systematically.According to theory analysis, the paper master the migration law and mathematic model of goaf gas, and built the foundation for numerical simulation; during the chapter of numerical simulation, the paper first time add two isolated working faces in3D-goaf physical model; Analyzing the simulation result and gas emission law, the paper get the result that during the process of mining, the goaf gas will inrush upper comer of working face largely, especially the gas come from near goaf close to ventilation roadway; So the key ways of solve the isolated working face upper comer gas concentration ultra-limit problem is interdict or reduce the gas inrush from self goaf and near goaf. Comparing the numerical simulation result of goaf gas concentration in different extraction scheme, the paper select the high-low position unite draining gas control technology. Analyzing and comparing measured value and simulation result of gas concentration: the average gas concentration measured value of transportation roadway high position fissure drill is9.87%, the simulation value is about10%. The average gas concentration measured value of transportation roadway and material roadway low position fissure drill separately is3.01%and2.91%, the simulation value is about from3%to5%; the average gas concentration measured value of upper corner and ventilation roadway separately is0.28%and0.19%, the simulation value separately is0.32%and0.25%. From the comparing result, the numerical simulation value is consistent with the engineering practice measured value, so the technology can guide coal mine production and the result shows the rationality of extraction scheme by simulation way. Adopting unite extraction measure later, the problem of gas ultra-limit in working face got solved, it guarantee working face safety mining, and provide reference for others mine gas control.