Study On The Response Characteristics And Reinforcement Of Roadway Surrounding Rock Under Dynamic Loading

The coal mine goaf roadway is located in an asymmetric stress field,and its dynamic loading environment also has regional characteristics.However,the current design of goaf roadway support does not consider the regional differences in its dynamic and static loading environment,which does not match the deformation and stress of the surrounding rock of the goaf roadway.In response to this issue,this article adopts methods such as numerical simulation,monitoring statistics,moment tensor analysis,and laboratory experiments to study the dynamic load response of tunnel surrounding rock.The stress and deformation characteristics of tunnel surrounding rock under dynamic load are analyzed,and the dynamic load mechanism and distribution characteristics of high-energy mining earthquakes around the tunnel are studied.A high resistance and large deformation anchor rod was proposed based on the demand for anchor rod support performance in dynamic loading tunnels,and its performance was tested and theoretically analyzed.Finally,taking the roadway support design of a specific working face on site as the object,the roadway support design was compared and optimized,and the support effect of the designed high resistance and large deformation anchor rod was verified.The main conclusions of the thesis are as follows:(1)The response characteristics of tunnel surrounding rock under different dynamic and static load conditions were simulated and studied,mainly including: the farther the dynamic load is from the tunnel,the smaller the disturbance to the tunnel;The response of the surrounding rock of the tunnel to the dynamic load impact angle has symmetry;The dynamic load response of the coal pillar wall is always greater than that of the solid coal wall,and the dynamic load response of the top plate is also always greater than that of the bottom plate;As the size of the coal pillar increases,the danger of the tunnel shows a trend of first increasing and then decreasing,and the response of the surrounding rock of the tunnel is most obvious when the coal pillar is between 10 m and 20 m.(2)The moment tensor inversion method was used to study the focal mechanism of high-energy mining earthquakes in the goaf and solid coal roadway during the mining period of W1103 working face.The main type of seismic source fracture within the 100 m plane around the goaf and solid coal roadway is tension fracture,and the occurrence of the fracture surface is as follows: the strike of the main fracture surface of the left roof of the goaf is 158.19°,with an inclination angle of 31.49°;The strike of the main fracture surface of the roof on the right side of the goaf is 150.39°,with an inclination angle of 18.58°;The occurrence trend of the main fracture surface on the left roof of the solid coal roadway is 143.39°,with an inclination angle of 34.50 °;The occurrence trend of the main fracture surface on the right roof of the solid coal roadway is 216.16°,with an inclination angle of 20.17°.(3)Analyzed the distribution characteristics of mine tremors within a 100 m plane range of empty tunnels and solid coal tunnels facing W1103 work.Among them,the horizontal and vertical distances between the roof earthquake on the left side of the goaf and the goaf are 29 m and 103 m respectively,and the average energy of the seismic source is 4.07E+04J;The horizontal and vertical distances between the mining earthquake on the right roof and the goaf are 45 m and 74 m respectively,with an average energy of 1.02E+05J from the seismic source.The horizontal and vertical distances between the left roof of the solid coal roadway and the solid coal roadway are 48 m and38m,respectively,with an average energy of 7.78E+04J for the seismic source;The horizontal and vertical distances between the right roof mine earthquake and the solid coal roadway are 41 m and 16 m,respectively,with an average energy of 9.46E+04J at the source.(4)A new type of high resistance and large deformation energy absorbing anchor rod was proposed,and the working performance of a special energy absorbing structure was experimentally studied.The factors affecting the working resistance of the energy absorbing structure were analyzed.Based on preliminary experimental results and theoretical analysis,the working performance of high resistance and large deformation energy absorbing anchor rods was obtained.(5)In response to the problem of mismatch between the original support scheme of W1103 goaf and the deformation and stress of surrounding rock,two support optimization schemes were proposed.A comparative analysis was conducted on each scheme from the aspects of tunnel surrounding rock response and anchor rod working state,and a suitable support scheme was determined.(6)The simulation verified the control effect of high resistance and large deformation energy absorbing bolts on the surrounding rock of the tunnel,and studied the working performance of high resistance and large deformation energy absorbing bolts under different dynamic loads.Under the action of high-energy mining earthquakes,compared to ordinary anchor rods,high resistance and large deformation anchor rods have a strong energy absorption effect,which can protect the safety of the support system.The thesis has 91 drawings,39 tables,and 75 references.