岩体变形及二次应力下矿体开采效应研究

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

为了解围岩在变形及二次应力下矿体开采效应的影响,本文选取-410 m中段采用现场试验与数值模拟相结合的方法对崩落法采矿进行矿体效应研究。结果表明:围岩应力发生震荡变化,在矿体上下盘围岩附近存在应力明显降低区域,下盘大于上盘,顶板最大主应力达0.44 MPa,局部呈现应力集中,且应力集中部位呈现类似水平零散分布的现象。同时开采边界呈现裂隙发育的状态。水平矿体有轻微下沉趋势,且在该中段的水平巷道边界和顶板裂隙附近易出现断层破碎带。竖直方向变形明显,且倾斜部位呈椭圆分布,最大下沉位移值达8.00 mm,最大上升方向变形值为3.03 mm,交界线附近易受到应力挤压现象。该研究对及时准确地掌握岩体变形规律和矿山安全信息使矿山安全有效合理地进行开采具有一定的指导意义。

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.