Study On Deformation And Instability Mechanism Of Deep Soft Rock Roadway

Deep mine exploitation is the development trend of China's coal resources development.In order to solve the problems of deep well soft rock roadway support failure,severe deformation and poor safety and stability,this paper takes 020202 track roadway in Qingyun Coal Mine as the research object,and combines the existing "bolt(sand)+ metal mesh" combined with the mining roadway.The support method is used to analyze the deformation of deep soft rock mining roadway with large deformation,severe deformation of the watch components and large deformation range.The field deformation,laboratory research,theoretical analysis and numerical simulation method are used to study the deformation of deep soft rock roadway.The mechanism of instability.The main research conclusions are:(1)Through the field measured data of 020202 track level in Qingyun Coal Mine,the deformation of different sections of the roadway is analyzed.The displacement of each part of the roadway is: bottom plate > left gang> right gang> top plate.Based on the limit equilibrium theory,the formula of the radius and surrounding displacement of the plastic zone of the roadway is derived.From the qualitative and quantitative perspectives,the effects of buried depth,rock mass strength,support resistance and mining stress factors on the displacement of mining roadway are analyzed.(2)Using the numerical simulation software to establish the working face mining roadway model,the variation characteristics of the plastic zone,displacement and stress of the roadway surrounding rock with the mining effect are analyzed,which shows that the mining support pressure generated during the advancement of the working face is related to the surrounding rock of the mining roadway.Deformation and failure play a leading role,and the mining stress concentration factor is determined.It is clarified that the large deformation of the surrounding rock of the roadway is the malignant expansion of the plastic zone of the surrounding rock.(3)The plastic zone radius and surrounding displacement under three lithological conditions of mudstone,coal and sandy mudstone were obtained,and the deformation relationship of surrounding rock strength-support-plastic zone-surrounding rock was established.(4)The core of the control to prevent the malignant expansion of the plastic zone boundary is to improve the strength of the rock mass in the plastic zone of the surrounding rock and improve the stress environment of the plastic zone.It is recommended that the 020202 track leveling adopt the joint control scheme of “surrounding rock grouting + support parameter optimization”.The surrounding rock control effect is remarkable.