| In recent years,with the increase in coal mining intensity,the relationship between mining and succession has been generally tense,and mines often have roadways that face the mining face(hereinafter referred to as "welding roadways").This kind of roadway needs to experience the dynamic pressure of the whole process of lateral roof breakage,rotation and stability of the goaf adjacent to the working face.The deformation and damage of the surrounding rock of the roadway are serious,especially the large-section full coal roadway,the mine pressure is more intense.Maintenance is extremely difficult,which seriously restricts the safe and efficient mining of coal mines in China.This paper takes the 15201 return wind channel of Mabao Coal Mine as the research object,and comprehensively adopts methods such as on-site investigation,laboratory rock mechanics parameter test,on-site roof peep,roadway surrounding rock loose circle test,numerical simulation and on-site industrial test.The layout and support technology of the mining roadway in the large section of Bao Coal Mine,the work carried out and the conclusions reached are:(1)The study analyzed the geomechanical characteristics of the surrounding rock of the large section roadway,and grasped the rock mechanical parameters of No.15 coal seam roof and floor.The research found that the overall strength of the roadway roof and floor is low and the direct roof and floor are mudstones that are easily met with water;After mining layout,the roadway pressure characteristics are as follows: severe roof deformation,broken ribs,obvious bottom drum,deep roadway loosening ring depth,coal pillar side loosing depth reaches 1.60 m in the mining area,and mining flank loosening depth Reached 1.18 m.(2)The numerical simulation analysis of the reasonable coal pillar width and the surrounding rock deformation and failure of the roadway is carried out.The research shows that the surrounding rock deformation of the roadway is asymmetric,and the deformation of the coal pillar and roof is relatively serious.As the width of the coal pillar increases,the peak stress of the coal pillar and the deformation of the surrounding rock gradually decrease.And determine the reasonable width of the coal pillar is 30 m.(3)According to the deformation characteristics of the roadway with large section,the high-strength,high-pretension,and asymmetric coupling support technology are proposed: the reinforced support of the pillar anchor cable + the reinforced support of the roof anchor cable network.Through numerical simulation calculations,the supporting parameters of the roadway under the large section under the 30 m coal pillar were determined;and it is concluded that the pressure of the surrounding rock of the tunneling roadway in the range of 30 m in front of the 15203 mining work and 40 m behind the working face is large.During this period,the deformation of the surrounding rock of the tunnel is quite intense.(4)The regularity of the measured rock pressure in industrial tests is as follows: the deformation of the surrounding rock of 15201 return wind along the channel undergoes four stages: excavation influence,excavation influence stability,mining influence and mining influence stability.The range of the mining influence stage is that it starts to affect when it is about 35 m in front of the working face near 15203,and it stabilizes to about 140 m behind the working face.The influence is significant from the working face 0 m to about 38.5 m behind the working face.Up to 34 mm/ d.(5)The results of on-site application show that the tunnels with wide pillars and high-strength,high preload,asymmetric coupling combined support technology can effectively control the deformation of the surrounding rock of the mining roadway in the Mabao Coal Mine with large cross section maintenance problems.Through the research and field practice of this subject,it provides a theoretical basis and technical approach for the control of surrounding rock in the large-section face mining roadway. |
PDF Full Text Request