Study On The Combined Support Technology Of Cable And Grouting For Roadway Driving Along Goaf In Xutuan Coal Mine

Coal consumption and production have been the top priorities of China's economic development since the beginning of this century.However,with the continuous exploitation of shallow coal resources in China for many years,the shallow coal mine resources have nearly dried up,and in order to improve the resource extraction rate,However,the support problem of driving along the goaf has not been solved.This paper takes the geological and technical conditions of the 3₂39 wind roadway in Xutuan Coal Mine as the research object,knows the difficulty point of roadway support,analyzes and deals with the factors that have a greater impact on the roadway deformation in time,and analyze the law of rock stress change,roadway surrounding rock support mode and change through theoretical analysis and numerical simulation.The defects of the form mechanism are studied.The working mechanism of anchor cable injection is studied.According to the results of the analysis of the action mechanism,a joint support scheme of deep anchor cables along the empty roadway is designed,and the theoretical calculation is simulated and verified by numerical simulation means.Finally,the rationality of the optimized scheme is verified through the research method of engineering practice.Through these means,the deformation instability characteristics and new support technology of 3₂39 wind tunnel support of Xutuan Coal Mine are studied in multiple aspects.The main research of this paper is as follows:(1)Analyze the deformation and failure mechanism of the coal pillars of the roadway driving along the goaf,and improve the original support methods of the roadway surrounding rock.After systematic research on the stability of the surrounding rock of the roadway driving along the goaf,the mechanical model of the surrounding rock of the roadway driving along the goaf is established,the characteristics of the stress field in the deep coal body from the edge of the goaf area are studied,and the supporting pressure distribution characteristics of the small coal pillars are described.The calculation formula of surrounding rock deformation and broken zone width is derived.In addition,it also makes a more accurate prediction of the evolution law of mining pressure along the goaf,and accurately analyzes the evolution law of mining pressure along the goaf of the stope,which provides a strong guarantee for the design of roadway support.Finally,by analyzing the control mechanism of anchor cable injection,combined with the maintenance characteristics of the roadway such as high stress,broken surrounding rock and large deformation,the anchor cable injection reinforcement support plan is determined,and the optimization of the roadway support design is realized.(2)The mechanism of anchor-cable grouting reinforcement was analyzed,and it was decided to use delayed grouting reinforcement to further optimize the supporting plan.Grouting can effectively improve the performance of rock and soil,but it is necessary to grasp the timing of grouting and choose reasonable grouting parameters.In the early stage of roadway excavation impact,“protection”and“giving”should be the main priority,that is,no strong support means are used.After the surrounding rock is fully deformed,the joints and cracks of the surrounding rock strata are fully developed.At this time,anchor-cable grouting support is performed.To achieve a better grouting effect,and the anchor cable will form a bearing structure with the surrounding rock and form a greater support resistance to the internal surrounding rock.(3)Study the surrounding rock stress and displacement deformation of the roadway along the goaf in inclined coal seams during the disturbance period of excavation,the stable period of excavation influence,and the stable period of stoping influence.Heading 5 m ahead is strongly affected by the excavation disturbance,15 m ahead is still affected by the excavation disturbance,but the impact slows down.Beyond25 m ahead is a stable area of excavation disturbance,which is basically not affected by mining;5 m,15 m frontward The vertical stress distribution of 25 m and 35 m is similar.The stress concentration occurs on the left and right sides of the roadway,but the small coal pillar on the right side of the roadway is close to the goaf,and the range and peak value of stress concentration are much higher than that of the roadway.Left Gang.(4)Determine the reinforcement support program with appropriate spacing between rows and find that the anchor cable reinforcement support program is far superior to the original support program in terms of plastic zone,vertical stress,horizontal stress and roadway deformation.In terms of plastic zone,the anchor-cable injection and reinforcement support program can significantly improve the plastic zone distribution of surrounding rock;in terms of vertical stress and horizontal stress,after anchor-cable injection and reinforcement support,the stress concentration range and peak value of the surrounding rock of the roadway are significantly reduced In terms of roadway deformation,the deformation of the lower roof of the anchor-cable reinforcement support is reduced by 56.7%compared with the original support,the deformation of the floor is reduced by 25%,and the deformation of the two sides is reduced by 45%.(5)Combining with the geological conditions of Xutuan Coal Mine,apply the optimized reinforcement support plan to engineering practice.Under this support scheme,design the coal tunnel control technology scheme and construction technology,and monitor the deformation of the 3₂39 air tunnel,which is basically consistent with the simulation results.After a small amount of deformation,it still meets the requirements of ventilation pedestrians,achieving the mine's expected goals and further verifying the anchor cable Note the feasibility of strengthening the support plan.The paper has 43 pictures,8 tables,and 60 references.