Theoretical Research On Zonal Deformation And Failure Of Surrounding Rock Of Deep Roadway

Zonal deformation and failure phenomenon is one of the engineering response characteristics of surrounding rock of deep roadway,and is a scientific problem that needs to be urgently studied and solved in deep rock mass mechanics.Zonal deformation and failure phenomenon of surrounding rock of deep roadway refers to the quasiperiodical distribution of deformation or failure zones of surrounding rock under the action of deep in-situ stress.In this paper,through indoor and field experiments,it is found that the main reason for the zonal deformation and failure of roadway surrounding rock is the heterogeneous distribution of strain caused by the meso/micro defects in coal and rock;the one-dimensional strain gradient model and non-Euclidean model for coal and rock under uniaxial compression are established,and the essential characteristics of heterogeneous distribution of strain are revealed,which provides the basis for the study of zonal deformation and failure of surrounding rock of roadway;the strain gradient elasticity model for circular surrounding rock of roadway,strain gradient elasticity model for surrounding rock of circular roadway under seepage action and non-Euclidean model for surrounding rock of circular roadway under seepage action are established,revealing the mechanism of zonal deformation and failure,and the judgment basis of zonal deformation and failure are obtained,which provides theoretical support for surrounding rock control of deep roadway.(1)Based on the field test of the amount of drilling cuttings in the ventilation roadway of 83003 working face in Laohutai coal mine at Fushun,the distribution regulation of the amount of drilling cuttings is studied.The formula of the relationship between the amount of cuttings and the stress of surrounding rock near the borehole is obtained.Through the analysis of the calculated quasiperiodical distribution of stress of surrounding rock near the borehole,it is proved that there exists quasiperiodical stress concentration phenomenon in surrounding rock of roadway.(2)Through the digital speckle test under the condition of uniaxial compression,it is found that the meso/micro defects and their gradient distribution in coal and rock mass are the essential cause of the zonal deformation and failure of surrounding rock of roadway.The value of internal size scale of coal specimens is obtained.(3)Based on the study of T-M strain gradient theory,the influence of strain gradient on deformation and failure of coal and rock mass is analyzed.One dimensional SGE model for coal and rock mass is established.The analytical solutions of displacement,strain and stress of one-dimensional SGE model under various conditions are obtained.Through numerical analysis,the influence of various parameters on one-dimensional SGE model is studied.In the one-dimensional SGE model,the mechanism of one-dimensional zonal deformation and failure of coal and rock mass is revealed,and the judgment basis of one-dimensional zonal deformation and failure of coal and rock mass is obtained.The rationality and validity of one-dimensional SGE model are verified by comparison with experiments.(4)Based on the study of non-Euclidean theory,the influence of incompatability variable on deformation and failure of coal and rock mass is analyzed.One-dimensional non-Euclidean model for coal and rock mass is established.The analytical solutions of displacement,strain and stress of one-dimensional non-Euclidean model are obtained.Through numerical analysis,the influence of various parameters on one-dimensional non-Euclidean model is studied.In the one-dimensional non-Euclidean model,the mechanism of one-dimensional zonal deformation and failure of coal and rock mass is revealed,and the judgment basis of one-dimensional zonal deformation and failure of coal and rock mass is obtained.The rationality and validity of one-dimensional non-Euclidean model are verified by comparison with experiments.The quasiperiodical stress of one-dimensional SGE model fluctuates at equal intervals;the stress of one-dimensional non-Euclidean model fluctuates at non-equal intervals.(5)The SGE model of zonal deformation and failure in surrounding rock of circular roadway and SGE model of zonal deformation and failure in surrounding rock of circular roadway under the action of seepage are established.The analytical solutions of displacement,strain and stress of these two models are obtained under various conditions.Through numerical analysis,the influence of various parameters on these two models is studied.In these two models,the mechanism of zonal deformation and failure of surrounding rock of deep roadway is revealed,and the judgment basis of zonal deformation and failure of surrounding rock of deep roadway is obtained.The rationality and validity of SGE model for zonal deformation and failure of surrounding rock of circular roadway are verified by comparison with experiments.(6)By applying non-Euclidean model,zonal deformation and failure of surrounding rock of roadway is studied.Non-Euclidean model for zonal deformation and failure of surrounding rock of circular roadway under the action of seepage is established.The stress analytical solutions of non-Euclidean model for zonal deformation and failure of surrounding rock of circular roadway under the action of seepage are obtained.Through numerical analysis,the influence of various parameters on these two models is studied.In these two models,the mechanism of zonal deformation and failure of surrounding rock of roadway is revealed.The rationality and validity of non-Euclidean model for zonal deformation and failure of surrounding rock of circular roadway and non-Euclidean model for zonal deformation and failure of surrounding rock of circular roadway under the action of seepage are verified by comparison with experiments.The SGE model belongs to the first-order SGE theory,and the non-Euclidean model belongs to the second-order SGE damage theory.