Mechanism and Simulation Study of Underground Tunnel Surrounding Rock Instability Under Advanced Support Pressure
[Purposes]This paper aims to study the evolution law of advance abutment pressure and the instability mechanism of surrounding rock in the coal face.[Methods]Taking coal mining face as an ex-ample,the elastic-plastic mechanics theory was used to analyze the characteristics of the pressure change of the lead support during the advancing process of the coal mining face,and the key layer theory under the action of the lead support pressure was discussed,which played a key role in the whole insta-bility process,and 3DEC simulation is used to study the failure characteristics of roadway surrounding rock under the influence of advance abutment pressure.[Findings]The results show that the surround-ing rock of the roadway presents asymmetric deformation,especially the asymmetric deformation of the two sides.With the mining process,the surrounding rock of the roadway is affected by the disturbance of superimposed stress,and the difference of the influence of the lead abutment pressure on the roof and the two sides of the roadway is mainly due to the high hardness of the roof rock as well as the relatively soft and broken coal body compared with the rock bed and the cracks in the side of the roadway have been produced ahead of time,which can release part of the roof pressure.[Conclusions]The results are of great significance to improve the stability and reliability of the system,enhance our understanding of the mechanism of instability failure,and provide important guidance for the prevention and management of instability.
support pressureinstability mechanismnumerical analysiskey stratum theory
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