The Simulation Analysis Based On FLAC For The Ground Deformation Of Mined-Out Area And Filling Effect

In underground mining production, due to a large area of mined underground, the roof of the rock lose their support, under its own weight, will bend, tension crack, falling, resulting in surface subsidence and collapse, a serious threat to the safety of mine, so carry out the research area of mining is necessary to empty.FLAC^3D software using the finite difference numerical simulation was carried out, mainly to complete the following tasks:(1) Through access to a large number of documents, the system summarizes the theory of subsidence history and the status quo.(2) Subsidence caused by underground mining of the basic characteristics of a brief introduction and summary. Including the form of overlying strata movement, three belts, failure modes and collapse of surface mined areas surrounding the scope and stress in the introduction and summary.(3) FLAC^3D software application simulation analysis of various factors on the surface deformation of mined influence reached the following conclusions:①The impact of mining depth: With the increase of mining depth, the surface deformation (vertical and horizontal) subsequently decrease.②Mining thickness: With the increase in mined thickness, surface deformation (vertical and horizontal direction) along with increasing.③Mining width: With the increased exploitation of the width of the surface deformation (vertical and horizontal direction) along with increasing shift; sink basin, the width of the range of mining increases with growing.④Overburden properties: With the increase of rock hardness, surface deformation (vertical and horizontal) was significantly reduced; in complex formations, the soft surface and lower hard stratum structure deformation (vertical and horizontal direction) than on the hard ground under the structure of the surface deformation of soft values (vertical and horizontal) small.⑤Topography: Gob areas of high terrain on both sides of the surface deformation than the low-lying areas of the surface deformation is larger.⑥Loose layer of impact: With the increase in loose thickness, in the other conditions being equal, the surface deformation was gradually increasing trend.(4) Projects filling effect on the simulation analysis, we can see gob after filling the surface deformation is small, so the filling of mined areas can effectively control the problem of mining collapse.