| In this paper,the air-return roadway of the 7607 working face of Wuyang Coal Mine is used as the geological engineering background,and by using the research methods of theoretical analysis,numerical simulation and industrial test,the influencing factors of the deformation and instability of the coal seam roadway are analyzed and anchoring mechanism of bolt in cataclastic rock mass and control measures of the stability of surrounding rock are systematically studied.The conclusions of the study are as follows: high surrounding rock stress,the weak lithology,fault structure and unreasonable support parameters are the main influencing factors of deformation and instability of the roadway.With the increase of bolt prestress value,the shear stress strength of joint increases and cataclastic area of surrounding rock mass decreases correspondingly.The stress-strain curve obtained by simulation shows that with the increase of bolt density and prestress value,the stress strength and elastic modulus of joint samples also show a positive correlation.With the increase of bolt length,the plastic zone and surface deformation of the roadway gradually decreased,and when the length of bolt is more than 2.4m,the decreasing trend become slower.For the characteristics and influencing factors of discontinuous large deformation of air-return roadway in 7607 working face,combined with the actual engineering conditions,the roadway is controlled by the combined support system of "resin extended anchoring bolt + anchor cable".The proposed five kinds of simulation programs are analyzed and compared to determine the optimal supporting program;and site monitoring data shows that the roof to floor convergence reduces 62% and two sides convergence reduces 70.1% on the average compared to the original support program.This shows that with the use of design support program,the surrounding rock stability is improved,and the deformation is controlled and good support effect is obtained. |
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