Study On The Stability Control Of Thick Coal Seam Roadway Cutting Top Unloading And Anchoring In Conjunction With Surrounding Rock

When there is a hard thick roof above the stope in advance can make under the influence of bearing stress along the empty roadway surrounding rock under high stress environment,and roof rotary in thick coal seam mining subsidence space is larger,the disturbance cycle and turbulence intensity along the empty roadway is larger,under high stress and strong disturbance along the roadway deformation damage is severe,empty roadway support hard to stability.This paper in order to hua jinlu jeannine downie coal mining thick coal seam roadway along the engineering background,aiming at the large mining height are broken,double side goaf,high stress,damage degree is high and difficult to maintain the characteristics of the thick coal seam roadway surrounding rock along the empty structure stress evolution,reveal the deformation of roadway instability mechanism,from the Angle of coal seam mining rock mass structure coordination proposed cutting roof pressure relief and anchoring the stability of surrounding rock control technology together.In view of the large structure of roof surrounding rock,the stress concentration degree of roadway is alleviated by the technique of cutting the top and relieving the pressure.In view of the small structure of roadway surrounding rock,reasonable anchoring support method and parameters are selected to increase the support strength,so as to mobilize the bearing capacity of roadway surrounding rock.The main conclusions are as follows:(1)Jeannine downie coal 2 # coal seam surrounding rock structural mechanics model is set up,and analyzing the characteristic of the goaf side of roof movement basic roof key block of roadway surrounding rock loading,using the theoretical formula and the mechanical model of roof pre-splitting unloading mechanism are analyzed,and found that the lateral stope above the longer the length of cantilever,sinking the turning Angle,the greater the roadway surrounding rock of the greater the load,so cut the cantilever beam decrease its length is the key pressure relief.(2)By means of discrete element numerical simulation,the whole process of thick coal seam mining is simulated,and the law of coordinated development of mining face mining stress and structure evolution of surrounding rock is obtained.(3)Using state of numerical simulation software of goaf roof top pressure relief and the parameters of the roadway anchor simulation analysis,comparative analysis of different cut top height(4 m,8 m,14 m and 18 m)different cut top Angle(0 °,15 °,30 °,45 °)and the degree of the goaf roof caving under different support way,roadway deformation of surrounding rock stress level,extent of damage,so as to determine the reasonable unloading-anchoring parameters.(4)According to numerical simulation of the optimal cutting roof pressure relief and anchorage parameters of physical simulation experiments and studies to determine the appropriate ratio of similar material parameters,using digital photographic brick,pressure box,respectively,monitoring system and the strain and cutting top unloading experiment model of overlying strata movement rule and in the process of stress evolution rule,analyzes the goaf pre-splitting along goaf of coal pillar and roof of roadway under the pressure and the effect of anchoring synergy along goaf roadway stability control mechanism.