Study On Movement Rule And Stability Analysis Of Counter-tilt Slope Under Combined Surface And Underground Mining

Combined surface and underground mining is a kind of valid way to maximize the recovery mineral resources. However, influenced by the two kinds of mining, the problems on the deformation rules and the stability of the slope under this condition become more complex and outstanding. How to evaluate the stability of the slopes under such condition, master the deformation, failure and displacement characters of the rock mass and set up the effective control methods has became the technical and security issues demanding prompt solution for the mining engineering. In this thesis, based on the top slope of Pingzhuang Western Surface Mine, the rock movement rule of the slope under combined surface and underground mining is studied with the combination of field research, theoretical analysis, similarity simulation test, numerical simulation, monitoring of surface displacement and hypothesis testing, then such conclusions and results are gained as follows:The affecting factors of slope stability in the surface mines are summarized, the deformation mechanisms of the slope under combined surface and underground mining are set forth, the effects of the underground mining on the slope of surface mines are analyzed, the failure types of the slope under combined surface and underground mining are put forward and the computing method for the stability of slopes under the influence of underground mining. The engineering geology characteristics of the top slope of Pingzhuang Western Surface Mine are analyzed systematically, the effects of the geological factor on it are discussed and the potential landslide mode of the slope is determined. With the similarity simulation test, the deformation and failure characteristics of the strata over the undergroud mining area and the subsidence characteristics of the land surface at different times are revealed and the influence of undergroud mining on the slope of surface mines is analyzed. The stability of counter-tilt slope under simple surface mining and it under combined surface and underground mining is analyzed respectively, the deformation, failure, displacement and stress distribution characteristics of the slope are expounded and the reason of the decrease stability the slope under combined surface and underground mining is analyzed. By analysis of the displacement-time characteristics in the process of the slope deformation, the basis to judge the slope stability is put forward. By reorganization analysis of the monitoring data of surface displacement, the main affecting factors of the slope deformation, such two deformed regions in the counter-tilt slope under combined surface and underground mining are put forward as the rising region and the subsidence region, the range influenced by the underground mining is selected and the present stability and relatively instable area of the slope. Based on the principles of hypothesis testing, the distribution characteristics of displacement velocity and acceleration at different times of the slope deformation are analyzed by the distribution configuration testing, then a new method that can dynamicly draw the impending landslide moment is brought up, which can promote the reliability of the early warning of landslides.