:Study On Deformation And Failure Mechanism And Control Technology Of Surrounding Rock In Roadway Near Fault

In the construction and production of mines,the excavated roadways will encounter areas with poor geological conditions such as fault structural belts.In view of the complex and changeable surrounding rock and serious deformation of surrounding rock in the roadway adjacent to the fault,this paper adopted the methods of on-site investigation,laboratory experiment,numerical simulation,similarity simulation and theoretical analysis to study the deformation and failure characteristics of the surrounding rock in the roadway adjacent to the fault,revealing the fault.The deformation and failure mechanism of the surrounding rock of the roadway in the adjacent area,further optimize the original support scheme,and finally form a supporting technology suitable for the surrounding rock of the roadway in the adjacent area of the fault.At the same time,the developed support technology could also be applied to other mines with similar geological conditions.By surveying the surrounding rock environment of the roadway in the adj acent area of the fault,testing the support performance of the original roadway surrounding rock,and analyzing the causes of roadway deformation and destruction,Summarizing the influencing factors of the deformation and failure of the surrounding rock of the roadway,it was obtained that the lithology,stress environment and geological structure of the surrounding rock were the main factors leading to the deformation and failure of the roadway.The stress field,displacement field and plastic zone evolution law of the surrounding rock of the roadway in the adjacent area of the fault were analyzed through numerical simulation,and the stress,displacement and plastic zone change of the surrounding rock of the fault over-return wind shun trough were clarified:There was an obvious stress concentration area at the top plate of the surrounding rock of the roadway,and the maximum main stress of the roof plate was 10 MPa,which was about 1.4 times the stress of the original rock;the vertical displacement of the top bottom plate of the roadway was obviously greater than the horizontal displacement of the two gangs;The depth of destruction of the plastic area at the corner of the roadway was large,and the entire fault zone was completely in a state of plastic destruction.Through physical similarity simulation experiments,grasp the failure characteristics of the surrounding rock of the roadway,It was concluded that the initial pressure step distance of the overburden was 35 m,the average cycle of the pressure step was 11.4 m,and the influence range of the advanced support pressure was 20 to 30m,so the advanced support range should not be less than 20 m.In view of the instability of the surrounding rock of the roadway caused by the 201 return wind downtrough fault,the HoekBrown criterion was introduced.From the perspective of the mechanical mechanism of the roadway crossing fault,a mechanical analysis model was established to analyze the deformation instability criterion of the surrounding rock of the roadway in the adjacent area of the fault.Finally,the critical value of the roadway surrounding rock failure instability in the adjacent area of the fault was determined to be 2.4～4.8m.On the basis of mastering the deformation and failure mechanism of the surrounding rock in the roadway adjacent to the fault,the "weak structure support" system was finally proposed:on the basis of anchor rod+steel mesh+anchor cable beam support,anchor cable reinforcement support was carried out,and the joint support system of hydraulic monomer pillar was cooperated.The support parameter was applied to the actual mining on site,and the relevant onsite construction process was formulated,which ultimately ensures that the support equipment could be safely and efficiently applied to the site.