Study On Laws Of Deformation And Failure Of Overlying Strata With Backfilling Mining Method For Xima Mine

Deformation and failure characteristics of overlying strata controlled by filling method are different from the characteristics controlled by caving method.It has important and directive significance for mining water prevention,gas migration law,protective seam mining,gas extraction and surface movement deformation control to master the characteristics.Anciently,the study of strata deformation and failure rules mainly focused on caving method under the condition that most mining height is higher than 1.0m.Therefore,this paper focus on the deformation and failure characteristics when the equivalent mining height less than or equal to 1.0m in the process of filling mining.An analysis method about deformation and failure characteristics of overlying strata in the process of filling mining is established based on the plates and shells theory,"shell-crack analysis method about deformation and failure characteristics of overlying strata",and I develop software called deformation and failure characteristics analytic system of overlying strata in the process of filling mining on the basis of the analysis method.Shell-crack reveals the formation condition of fault zone and caving zone in the process of filling mining.What’s more,this method could analysis the disappear condition of fault zone and caving zone and the development height of fault zone and caving zone when the equivalent mining heights are different.Applying Transfer Rock and Beam hypothesis to analysis distribution regularities of advanced support pressure before fracture and after fracture and get a result that the main factors influencing the advance support pressure is the equivalent mining height,suspended span,and the height of overlying strata destruction.As the research background in geological and mining conditions of 1327 working face,applying shell-crack analytical method and numerical simulation method to analysis the deformation and failure characteristics of overlying strata in working face when the equivalent mining heights are different.All the result of two kinds of methods shows that there are critical effect in the formation fault zone and caving zone.Put theoretical analysis and numerical simulation together,we could draw a conclusion that the destruction scope limits of overlying rock of 1327 working face is 12.80 m,the scope of the first roof weighting pace is 19.2 m～20.2 m,the periodic roof weighting pace is 16.5 m.Designing monitoring scheme which to monitor roof-to-floor convergence,stress of working face,roadway advanced support pressure and broken height of overlying strata of 1327 working face in the process of filling mining.The results of the monitoring is analyzed by appropriate mathematical methods,and then contrasting the result of actual measurement to the results of theoretical calculation and numerical simulation.It shows that the comparison results are highly anastomosed.The result proves the foregoing law about deformation and failure characteristics of overlying strata,and it proves the analytical method fore-established has a higher precision.It meets the requirement of field application.