Layout And Support Technology Of Roadway In Coal Pillar Working Face Of Yonghong Coal Mine

Our country encourages the safe recovery of residual coal such as protective coal pillars and corner coal in qualified roadways.The protective coal pillar of the main roadway is affected by multiple mining activities.The mine pressure behavior when the coal pillar is recovered is different from the conventional situation.There are three problems : reasonable layout of the mining roadway,control of the surrounding rock of the roadway and passing through the empty roadway.In this thesis,the coal pillar of the main roadway in the fifth mining area of Yonghong Coal Mine is taken as the actual engineering background.The research methods of indoor experiment,theoretical analysis,numerical calculation and field test are comprehensively used to study the stress distribution law in the coal pillar of the main roadway in the fifth mining area,the layout of the mining roadway,the support technology of the surrounding rock and the empty roadway.The main achievements are as follows :(1)Reasonable layout of mining roadway in coal pillar working face of main roadway.Based on the principle of recovering more coal resources and controlling the deformation of roadway surrounding rock,the width of plastic zone of coal pillar edge in main roadway,the stress distribution in edge coal body and the deformation of surrounding rock during roadway excavation and mining are studied.(2)Surrounding rock control technology of normal section roadway.Based on the stress and deformation characteristics of surrounding rock during roadway excavation and mining,the ’ partition and segmentation ’ surrounding rock control technology of mining roadway is proposed.Theoretical analysis shows that the stability of roof support is the most important factor affecting the quality of roadway support.The mechanism of shed-cable cooperative support in normal section is obtained by numerical simulation,that is,(1)the stability of shallow surrounding rock of roadway roof in large deformation section is mainly controlled by shed support,and the stability of shallow surrounding rock of roadway roof in small deformation section is mainly controlled by the bearing capacity of surrounding rock itself.(2)The anchor cable mainly plays a leading role in the shed-cable cooperative support system in the large deformation section,and the I-steel shed mainly plays a leading role in the shed-cable cooperative support system in the small deformation section.Based on the theoretical calculation and numerical simulation results,the surrounding rock support scheme of 800 mm shed spacing,1000 mm anchor cable support row spacing,’ 3-2-3 ’roof anchor cable arrangement and local short anchor cable reinforcement support of shed leg is determined.(3)Surrounding rock control technology of roadway in empty roadway section.The mechanical model of the disturbance of the empty roadway to the heading face is established.Based on the elastic-plastic theory,the limit disturbance horizontal distances of the empty roadway and the mining roadway in the lower and upper layers are 6.85 m and 6.73 m respectively.Numerical simulation is used to analyze the stress and deformation characteristics of surrounding rock of all kinds of empty roadways in mining roadway excavation,and the timely support opportunity and strengthening support object of all kinds of empty roadways in mining roadway excavation are obtained,and the support scheme of surrounding rock of empty roadway in mining roadway excavation is put forward.(4)Industrial test.The industrial test was carried out in the coal pillar working face of the main roadway in Yonghong Coal Mine.The mine pressure data showed that the roof subsidence during the roadway excavation was less than 80 mm,the two-side convergence was less than 150 mm,the maximum force of the anchor cable was 70 k N,and the maximum force of the bolt was 37 k N.It shows that the reasonable layout of roadway and the control technology of ’ partition and segmentation ’ roadway surrounding rock can meet the requirements of deformation stability and safety support of surrounding rock of mining roadway.There are 107 Figures,19 Tables and 71 References in the dissertation.