Study On The Engineering Application And Supporting Technology For Soft Rock Roadway In Deep Mine

The mine is composed of ventilation,coal transportation,gangue discharge and other systems.The various production systems are complexly interlaced,so roadway intersections widely exist in the production system.Crossroads are prone to form crossover points with large empty roof area,complex stress environment and multiple excavation disturbances.And with the deep mining of coal,the surrounding rock of the deep roadway suffers from "three highs and one disturbance",which makes the deformation of the surrounding rock large and the extent and extent of damage worsened.In order to solve the problem of roadway instability caused by the large deformation of the crossing roadway,this paper is based on the engineering background of the 2121(3)rail along the feed roadway in the East 1st mining area of Pansan Coal Mine.Through indoor rock mechanics tests,theoretical analysis,numerical simulation and on-site.The actual measurement and other means are used to optimize the parameters of the support scheme of the deep well crossing roadway.Finally,the support effect is fed back based on on-site monitoring,in order to provide a technical reference for the design of the surrounding rock support of the deep crossing roadway.Using laboratory rock mechanics test and in-situ stress monitoring,it is obtained that the compressive strength of surrounding rock of 2121(3)track feeding roadway is 42.35MPa,and surrounding rock lithology is weak.The maximum principal stress of Dongyi mining area is 29.3 MPa,and the direction Angle of principal stress is 190.64°,which belongs to the stratum with high in-situ stress level.Through theoretical analysis,the vertical stress distribution and stress concentration coefficient in the trigonometric area of the bifurcation roadway are studied,and the main forms and causes of the surrounding rock instability in the bifurcation roadway are analyzed.The combined support technology of "bolt+anchor cable+deep grouting" is put forward to effectively control the deformation of surrounding rock at the crossing point of roadway.Based on the numerical analysis,the support scheme of the intersecting roadway in Dongyi mining area of Pansan Mine is optimized.By comparing the deformation control effect of the intersecting area and the axial force of bolt and cable,the optimization scheme of the combined support parameters of "bolt+cable+deep grouting" is put forward.The influence of different bifurcation angles on roadway deformation is studied,and the results show that under the same support scheme,with the decrease of roadway bifurcation Angle,the deformation value of surrounding rock roadway increases.According to the deformation distribution law of the support structure in the crossover roadway,it is proposed that the support in the overlapping area of the crossover roadway should be paid attention to in the construction process of the crossover roadway,so as to ensure the control effect of the support structure on the roadway deformation.According to the field engineering application,the on-site monitoring scheme of disturbance effect analysis of roadway construction is formulated,and the crossing point of 2121(3)track feeding roadway in Dongyi mining area of Pansan Coal Mine is monitored and analyzed.Through the actual monitoring of the project,it is verified that the application effect of Scheme 7 in the actual project is significantly superior,and the numerical simulation results are basically consistent with the measured results.Figure[47]table[7]reference[86]...