Study on ore-body mining effect under rock mass deformation and secondary stress

In order to understand the influence of the mining effect of the surrounding rock under deformation and secondary stress,this paper selected the -410 m section to study the ore body effect of caving mining by combining field test and numerical simulation.The results show that the surrounding rock stress changes in shock,there is a stress reduction area near the upper and lower wall surrounding rock of the orebody,the foote is larger than the hanging wall,the maximum principal stress of the roof reaches 0.44 MPa,and local stress concentration.In addition,the stress concentration parts showed similar horizontal scattered distribution phenomenon.At the same time,the mining boundary presents the state of crack development.The horizontal ore body has a slight subsidence trend,and the fault fracture zone is easy to appear near the boundary of the horizontal roadway and the roof crack in the middle section.The deformation in the vertical direction is obvious,and the inclined part is elliptical distribution.The maximum subsidence displacement is 8.00 mm,and the maximum upward deformation is 3.03 mm.The stress extrusion phenomenon is easy to occur near the intersection line.The study has certain guiding significance to grasp the deformation law of rock mass and mine safety information in time and accurately so as to carry out mining safely,effectively and reasonably.