Research On The Stability Control Of Surrounding Rocks Of The Encounter Mining Roadway Of Mabao Mine

In recent years,with the continuous development of underground coal resources,the problem of alternate mining and excavation has become more prominent,which has led to the widespread application of the method of driving the roadway.Due to the superimposition of the influence of the adjacent working face and the disturbance of the roadway excavation,it is very easy to cause the roadway has a large amount of deformation,especially for large mining height working faces and large cross-section all-coal roadways,which are more difficult to maintain.Based on the engineering background of the roadway excavation of 15201 in the second mining area of Xindadi Mine of Yangmei Coal Mine,the method of combining indoor test,theoretical analysis,numerical simulation and on-site monitoring is used to analyze the behavior and failure characteristics of roadway rock pressure during 15201 return air tunnel driving and 15203 working face stoping.In-depth study of the deformation mechanism and control technology of the roadway in front of mining,And carried out the actual engineering application on the spot.(1)Through field sampling of the roof and floor of the coal seam,the RQD value of the basic roof and surrounding rock of the 15201 working face return airway is obtained.Based on the determination of the physical and mechanical parameters of coal,the 15 th coal and its roof and floor are obtained.Mechanical parameters such as tensile strength,compressive strength and elastic modulus provide parameter support for the stability study of the surrounding rock of the roadway.(2)Through the use of rock pressure monitoring,surrounding rock loose circle test and roof drilling peep on the 15201 return airway,the rock pressure characteristics and failure characteristics of the roadway surrounding rock are obtained.The deformation rate of the stable stage of mining influence is generally0.5?0.75mm/d,the depth of the loose circle near the 15201 return air trough meeting with the 15203 working face is relatively large,and the surrounding rock of the 15201 return air trough is of general unstable type IV.(3)During the excavation process of the 15201 oncoming mining roadway,the stress concentration stage of the adjacent working face has the greatest impact on the surrounding rock deformation of the oncoming mining roadway.As the distance between the 15201 return airway and 15203 working face is gradually reduced,the stress concentration mainly occurs inside the coal pillar body,the stress peak mainly occurs at 20?25m inside the side of the 15201 return wind along the coal pillar.For the areas affected by mining,a combined bolt + metal mesh + reinforced ladder beam+ anchor cable reinforcement support method is proposed.(4)Through the numerical simulation analysis of the surrounding rock deformation of the 15201 return air passage,the maximum deformation position appears at the position where the 15201 return air passage meets the 15203 working face.After the support measures are taken.After taking support measures,the deformation of the roof and floor of the roadway surrounding rock has decreased significantly,and the surrounding rock of the roadway can maintain good stability.During the on-site industrial test,MCS-400 bolt dynamometer and LBY-3surrounding rock displacement monitor were used to monitor the roadway bolt stress and roof separation.The results show that the stress change of the surrounding rock of the 15201 mining roadway is relatively stable,and the amount of roof separation is small,which can effectively control the stability of the surrounding rock of the mining roadway of Yangmei Xindadi Mine.This paper has 51 maps,16 tables and 77 references.