Study On Timing Characteristics And Stability Control Of Roadway Influences By Mining In High Stress Area

With the geological conditions of coal seam mining becoming more and more complex,the influence of mining on roadway pressure is more and more obvious.Especially in areas where faults and joints are developed,it is characterized by high stress and rock breakage.Therefore,it is of great significance to strengthen the research in areas with high stress.Deformation of surrounding rock in roadway during the period of service in order to solve such serious technical problems,not easy to control,based on the double willow coal mine 3316 face high stress zone mining roadway as the background,studies the high stress area extraction roadway surrounding rock stress and deformation,aging characteristics affected by mining and on the basis of optimized support scheme,good result is got in the engineering application and monitoring,and realized the mining affecting roadway surrounding rock stability control,and obtain the following main research conclusions:(1)The drainage roadway 3316 has a large buried depth and is obviously affected by the tectonic stress of nearby faults.The roadway is in a high stress environment as a whole.The test results of mechanical parameters of roadway rock samples show that the mechanical strength of roof and floor strata is low and the structure is broken.It can be seen that the soft surrounding rock and the weak bearing capacity of the roadway are the fundamental reasons for the distortion of the roadway roof,the serious swelling and falling of the side and the overall instability of the surrounding rock.(2)The influence mechanism of working face stoping on 3316 mining roadway and the change process of roadway under the influence of stope stress in the process of working face advancing are analyzed by using the ore pressure control theory.FLAC^3D modeling was used to analyze the aging characteristics of the influence of mining in the roadway.The results show that the evolution of mining stress in the coal pillar has obvious stage characteristics,that is,the peak value of mining stress is the highest at the working face 80m above the roadway measuring station,and the stress concentration coefficient is up to 2.96.(3)The field monitoring results of anchor bolt(cable)show that,in the process of mining,from 50 m before the station arrives to 20 m beyond the station,the roadway support structure is less affected by mining;During the period from 20 m beyond the station to 80 m beyond the station,the roadway support structure was obviously affected by mining.After 80 m beyond the station,the mining influence gradually leveled off.After mining,the load of anchor bolt(cable)increases greatly compared with that before mining,and the reinforcement coefficient of mining influence reaches 2.1?5.8.(4)The actual measurement and analysis show that the strength of coal pillar wall and solid coal wall affected by mining in 3316 mining roadway is different and has asymmetry,and the average coefficient of mining influence enhancement under the working load of coal pillar wall anchor(cable)is 27.3%higher than that of solid coal wall.(5)The comparison of in situ detection of roof surrounding rock shows that the increase of mining induced stress leads to the increase of secondary fractures and the expansion of fracture range in the shallow surrounding rock,especially within the range of 0?2.4 m.The crack expansion reduces the cohesion of roof strata.(6)according to the mining influence mechanism of extraction from lane and destruction features,by improving the support strength bolts and cables on the original support scheme,the corresponding optimization,scheme of roadway roof subsidence compared with the original support scheme was reduced by 86.2%,the two sides closer quantity is reduced by 89.1%,better control surrounding rock stability.