Mining Failure Law Of Ultra-Wide Working Face Floor In Zhuzhuang Coalmine And Application Of Prevention And Control Water Engineering

Zhuzhuang Coalmine is located in Huaibei City,Anhui Province,which the hydrogeological conditions of the coal 6 floor have undergone major changes after the advanced treatment of the limestone aquifer of the Taiyuan Formation through surface area treatment.On the basis of the above hydrogeological work,this thesis takes the III635 working face where next to the III601 ultra-wide working face of Zhuzhuang Coalmine as an example.The hydrogeological structure and parameters of the working face floor was obtained through on-site exploration,the mining failure law of coal 6floor was obtained through literature research,empirical formula prediction,on-site measurement and numerical simulation.The research results of the working face was applied to carry out the analysis of the mining law of the III601 ultra-wide working face floor.The main results of the thesis are as follows.(1)The hydrogeological structure characteristics and parameters of the floor of the ultra-wide working face were obtained through the design of special hydrogeological exploration holes.The structural characteristics and combination relationships of rock strata from coal 6 floor to 3 ash layers were obtained by drilling and sampling.A representative 15.64 m core was selected,and the density,elastic modulus,cohesion,tensile resistance,compressive resistance and other petrophysical and mechanical parameters of each rock layer of the floor were calculated by means of uniaxial compressive(shear,tensile)test.And the uniaxial compressive strength of the saturated coal 6 slate layer was generally between 30～60MPa,which had high mechanical strength and was divided into medium and hard rock layers.(2)The mining failure process and law of ultra-wide working face floor were comprehensively studied and revealed.The ground-measured pressurized water test scheme of the failure depth of the III635 working face floor was designed,and the maximum failure depth of the floor during the mining process of the working face was18.4m.At the same time,based on the structure and parameters of the III635 working face slate layer,the numerical model was adjusted through numerical simulation and combined with the actual geological parameters of the III601 ultra-wide working face to simulate the mining failure process of the floor,which design mining width were235,248,270 and 300 m respectively.The results showed that the maximum failure depths of the coal seam floor were 21.32 m,22.84 m,24.58 m and 28.65 m respectively.The statistical analysis of the failure depth data of similar working face floor,empirical formula and numerical simulation analysis results,the influence law of working face width were combined to obtaine the advance distance on the failure depth of the floor.(3)The application of water inrush risk evaluation and optimization of working face size of ultra-wide working face floor was carried out.Applying the research results,the water inrush coefficient method and the Slesalev formula method were used to analyze and evaluate the water inrush risk of the working face floor under different design width conditions.And the safety of the floor with pressure mining was comprehensively evaluated by combining the evaluation of the anti-destructive ability of the working face floor and the prediction of water inflow.Applying the above results,the theoretical safety surface width of the ultra-wide working face size design of Zhuzhuang Coalmine and the entire Huaibei mining area after the treatment of the floor area is 300 m,which can be used as the basis and reference for the size design of the working face in the mining area.The theoretical safety surface width of the mining failure law and the size design of the working face after the ultra-wide working face floor of Zhuzhuang Coalmine passes the treatment of the ground area were obtained through the thesis research,which have certain theoretical and practical guiding value for the design of the working face size of mines with similar mining conditions and the development of floor water prevention and control.The thesis has 53 pictures,33 tables,and 100 references.