Research On Failure Mechanism And Repair Technology Of Surrounding Rock Of Soft Rock Uphill In Fault Tectonic Area Of Zhuxianzhuang Coal Mine

With the development of national industry,coal mining will inevitably develop into complex stress environments such as "deepening","softening",and "breaking up".The deep soft rock roadway located between the forward and reverse faults in the fault structure shows The non-linear long-term large deformation caused by the combination of multiple deformation mechanisms can cause long-term large deformation,rheological creep,asymmetric damage,and complete failure of the support body.Such phenomena are also increasing day by day,and the matching degree of the current support form with the asymmetric and unbalanced deformation and failure of the roadway is very low.This paper uses on-site surveys,numerical simulations and industrial experiments to study the supporting mechanism and technology of soft and broken surrounding rock in deep wells.The main results are as follows:(1)The general situation of the mining area is explained,and it is concluded that the lithology of the roof and floor of the main coal seam is mostly engineering soft rock such as mudstone,and the main distribution range of the weak layer includes rocks in the weathering zone,fault fracture zone and mudstone.Based on the analysis of ?5track uphill roadway layer selection that blindly leads to asymmetric large deformation failure and the lack of passive support of the original frame shed leading to the serious disrepair of the support failure roadway,the long-term large deformation and failure characteristics of the surrounding rock of the roadway and maintenance aspects are clarified.With various difficulties,it is preliminarily drawn that the study of the stability control technology of the loose and broken surrounding rock can effectively control the long-term large deformation and failure of the roadway surrounding rock.(2)The loose circle test was carried out on the five stages of the ?5 track uphill.The results show that the loose circle is larger at the bottom of the roadway and the bottom left corner,and the damage mechanism to the roadway,including the cause of the direct deformation of the surrounding rock,the macro stress environment and the long-term The deformation bearing characteristics are analyzed.Combined with the test results of the loose zone(greater than 3m),the intuitive reason for the uphill deformation and failure of the II5 track is clarified,and the numerical model of the surrounding rock rheology reveals the root cause of the uphill deformation and failure of the II5 track.It is pointed out that when the II5 track goes uphill without support,the roadway presents a stage of attenuation-stabilization creep-accelerating creep,and it is determined that only active support methods such as grouting to improve the mechanical properties of the surrounding rock are the fundamental means to solve this type of problem.(3)Numerical calculation shows the failure process of the original frame support.Aiming at the difficulty of U-shaped steel passive support to adapt to the long-term deformation of soft rock and the action of high deep ground stress,it is proposed to build a shallow bearing layer of surrounding rock based on bolts/anchor cables.Shallow hole low pressure sealing and deep hole high pressure relief grouting improve the mechanical properties of surrounding rock,give play to the three surrounding rock control principles of the integration of bolting and injection and the coupling strengthening characteristics of supporting members and surrounding rock,and based on numerical simulation,the anchor is obtained.The parameters of the distance between rods and cables and the grouting range are obtained based on the evolution characteristics of the plastic zone and the test results of the loose circle.(4)Based on the engineering background of the soft and broken roadway in the deep shaft of Zhuxianzhuang Coal Mine ? 5 track,the repaired roadway "primary full-face short-anchor high-strength support + secondary deep and shallow hole grouting reinforcement support" and the newly excavated roadway "primary concession" were designed.Pressure support + secondary deep high-pressure splitting and grouting reinforcement support" roadway repair mode;formulate the mine pressure observation plan of ? 5 track uphill roadway,determine the layout of online observation points,monitoring content and monitoring purpose.The paper has 70 pictures,12 tables,and 73 references.