Research On Evolution Of The Multiple Field And Security Pillar In Condition Of The Closed Protective Seam Mining

The researching on Evolution laws of Multiple field and the Performance of security pillar in condition of the closed protection mining has challenged many researchs of the field of coal mine safety from the home and the abroad to devote them to it. As a base of studying the gas outburst preventing in condition protective layer mining, It Has an important theoretical significance and practical engineering value to research the mechanism of formation distribution and evolution of Gas field, displacement field,stress field, fracture field,plastic damage zone and the properties of strength,deformation,destruction and instability of the Security pillar between Protective layer and the Protected layer in condition of the protective layer mining For the people gain a better understanding of the protective layer of Outburst Mechanism,Plan and design protection layer, expand the scope of protection, optimize the protective effect and also take more effective measures for the prevention of gas outburst.Paper using Integrated the method of theoretical analysis, laboratory experiments, numerical calculation, computer simulation and field testing of parameters, taking the Pingdingshan Coal Industry Group Co., Ltd. as the research object, study the laws of the evolution of the Multiple field and the characteristics of the security pillar in conditions of the close protective layer mining. The conclusion Made more consistent with each other.On Theoretical analysis:using the konwledge of mining rock mechanics, mining theory,mechanics of coal permeability and gas geological theories, paper Analysised the rules of the evolution of the overburden stress field, fracture field and gas seepage in the process of protective layer mining and their influence on the destruction of a balanced systemof coal and gas.On physical simulation studies:Study the Movement andfailure process of rock and the Evolution laws of the "three-zone horizontal and vertical three-zone" in conditions of the close protective layer mining using the advanced level of mining engineering physical plane strain model, range finder, high-speed cameras, strain gauge and intelligent digital sampler. On Numerical simulation studies:Analysis of the full relief height with the overlying rock face of advancing,coal and rock fracturing pressure distribution range and bearing characteristicmining in the process of the protective layer using the Simulation software of the FLAC3D,UDEC,RFPA,SURFER ect.On Pillar of security studies:Considing the particularity of close Protection layer mining,the thesis studied the security with the method of numerical simulation study During the Close protection layer mining,Reached the minimum safety thickness of rock column during Tunneling, And carried out the danger of the dynamic partition,on this basis, Proposed protective layer of gas control measures during mining.On Field Application studies:Based on the above-mentioned study, Combined Minmetals mining, geological conditions of Pingdingshan Coal Group Co.Ltd.studied the mining process of the JI-15 protective layer above mining by the numerical simulation, Conducted a three-dimensional visual display, it is shown that the numercial results, Laboratory observations, the actual field test results about the closed protection mining can be a good fit.