Numerical Simulation Study On Support Of Deep High Stress Soft Rock Roadway In Chiyu Mine

After excavation and mining in deep soft rock roadway with high stress,under the coupling action of vertical stress and horizontal stress,stress redistribution will occur,and deformation and failure are difficult to control.It is of great significance to study the mechanism of surrounding rock breakage and design support scheme in the environment of high stress soft rock roadway for ensuring the stability of surrounding rock in deep complex geological environment.Taking Chiyu Mine as an engineering research background,this paper makes a thorough study on it by means of theoretical analysis,numerical simulation and on-site monitoring.Firstly,the mechanism of deformation and fragmentation of surrounding rock of deep roadway with high stress is studied by theoretical analysis.The determination of in-situ stress and the criterion leading to instability and displacement of roadway are carried out.It is concluded that the surrounding rock is a typical tectonic stress field,and the failure type of surrounding rock belongs to the Strength-Stress control type.The displacement and deformation are taken as the criterion of instability of high stress soft rock roadway according to the original design.According to the scheme and the situation of surrounding rock fragmentation in site,the supporting scheme is designed for the deep soft rock roadway with high stress of half trapezoidal section and straight wall arch section.The different supporting schemes are numerically simulated by numerical simulation software.The characteristics of surrounding rock deformation,stress and plastic zone of each supporting scheme are analyzed,and the stress and displacement of surrounding rock of roadway with different supporting schemes are searched.Change law and support effect analysis of anchorage parameters are carried out.Through comparative analysis,it is found that under the condition that the radial stress,tangential stress and displacement deformation of roadway surrounding rock are basically unchanged,when the bolt reaches the effective length,it is more reasonable to adopt short and dense support with long and sparse ratio.Considering comprehensively,0.7 x 0.7 x 2.0m bolt is selected for roof and two sides,and three 1.4 x 1.4 x 6.3m bolt cables are laid for roof and roof.A 2.0m bolt is installed on the inner side of the two pitch angles of the floor as the supporting design.Finally,through the field monitoring research means,the monitoring data analysis shows that the displacement and deformation of the roadway are small,and there are no roof subsidence,sheet side,floor heave and other phenomena.The design of the supporting scheme effectively solves the engineering problems.Fig.45 table 8 references 77...