Study On Pressure Behaviors Law And Surrounding Rock Control Mechanism Of Mining Roadway In Gently-inclined And Thin Coal Seam

In general,the mining roadway impacted by the mining under coal mine,referred to as "mining roadway".For mining roadway,there are some serious problem,such as serious damage to the surrounding rock,strata appears violent,difficult to control the surrounding rock,etc.In view of the above problems,this paper uses numerical calculation and on-site monitoring method to study the deformation,failure law and surrounding rock control technology of mining roadway.The main research contents and conclusions are as follows:(1)Get the overview of coal seam geological occurrence characteristics and working face through field research;The mechanical properties of the coal seam and the top and bottom of the obtained through laboratory tests to check the numerical test parameters by trial approximation method.(2)The calculation model of the 3D stope is constructed,and the regularity of the mining pressure in the coal mining process is analyzed by numerical simulation.The stress distribution and evolution law of the surrounding rock are analyzed under the step excavation condition,and the change rule of the bearing pressure in the side of the stope and the working face is obtained.The stress distribution of the bottom of the stope during the mining process is analyzed The results show that the stress distribution of the floor caused by the mining can reach about 6.7 times the height of the mining area,the bottom plate failure showed a "spoon-shaped" asymmetric failure.(3)Based on the elastic-plastic analysis of surrounding rock of roadway,it is concluded that the deformation of roadway surrounding rock is mainly determined by the original stress,the cohesion and internal friction angle of rock,the resistance of roadway support and the radius of tunnel excavation.Among them,the radius of the plastic zone of the surrounding rock is directly proportional to the radius of the roadway and the original rock stress,and is inversely proportional to the cohesion and internal friction angle and the roadway support resistance.(4)Based on the numerical analysis of double lane excavation,it is concluded that the spatial location of double lane has a significant influence on the deformation and failure of surrounding rock.With the increase of the horizontal and vertical errors,the interaction between the roadway decreases rapidly.The adjacent roadway has obvious influence on the dynamic load has been heading,with the increase of spatial distance,the top floor and two sides of relative volume significantly decreased;with the excavation distance approaching,adjacent roadway surrounding rock plastic zone is China Unicom;adjacent road vertical load of rock pillar in double lane side under the rock present shear failure form.The main reason for the increase of the deformation of surrounding rock is the superposition of the abutment pressure in the surrounding rock.(5)Through the numerical simulation of the tunnel support design under different stress concentration factors,it is concluded that the high stress concentration factor has significant influence on the deformation and failure of the surrounding rock.In the anchor density under different shaped roadway in high stress area mainly appeared in the roof at the top and two for help at the foot.Two for high strength support can effectively limit the large deformation of surrounding rock,but also easy to form a high stress concentration,not only in the two to help the formation of high strength of the stress concentration caused by the bottom edge at the foot of the larger shear stress concentration,resulting in destruction of heave.(6)Starting from the actual production,combined with field survey and mine pressure monitoring,comparative analysis of the roadway in coal seam excavation effect before and after the selection of truss cable reinforced timbering,mining roadway surrounding rock control effect is good.