Study On Stability Effect And Control Technology Of Roadway Surrounding Rock Near Fault

This thesis takes the deep level near fault roadway of Dongpang Mine as the background.The mechanical mechanism of fault formation is analyzed by means of theoretical analysis,numerical simulation and industrial test.The expression formulas of vertical principal stress,horizontal principal stress and shear stress after fault formation are deduced by establishing mechanical model.The deformation law of roof and floor of roadway near fault and the plastic zone range of protective coal pillar between fault and roadway are studied.The influence of geometric factors of strata on in-situ stress field near faults is studied.The stress distribution and deformation failure of roadway under protective coal pillars with different width faults are studied by numerical simulation software.The following conclusions are drawn:(1)The maximum principal stress,the horizontal principal stress perpendicular to the strike of the fault and the shear stress on the fault plane increase after the formation of the normal fault,and the value of the horizontal principal stress perpendicular to the strike of the fault is 1.81-5.47 times as much as that before the formation of the fault.(2)The stress concentration factor of roof at shoulder angle of near-fault roadway is the largest.On cross-section of roadway,the closer the distance between roadway floor and fault,the larger the floor heave,the width of plastic zone in protective pillar is positively correlated with the height of roadway,and negatively correlated with the support strength of coal pillar and the distance between roadway and fault.(3)Geometric factors of faults have great influence on the distribution of in-situ stress near faults.The higher the height of fault development and the thicker the fracture zone,the greater the stress concentration factor near the fault and the wider the range of in-situ stress rising area.On the contrary,the greater the dip angle,the smaller the stress concentration factor and the smaller the influence range.(4)Aiming at the characteristics of asymmetric deformation and failure of deep horizontal near-fault roadway,the supporting principles of high-strength anchor cable pre-tightening force active support,near-fault side and floor strengthening support and roadway side and bottom angle control and concession coupling support are adopted to effectively control the asymmetric deformation and failure of surrounding rock of nearfault roadway and prevent the floor shear slip caused by horizontal tectonic stress of fault.(5)Combining with engineering geological conditions,the reasonable protection pillar width of near-fault roadway is determined to be 20 m.In view of the uneven spatial distribution of geometric elements of faults,different supporting measures are adopted for different sections of roadways by means of subsection support.