Study On Three-dimensional Stability And Its Control Of Dip Bedded Soft Rock Slope In Surface Coal Mine

Stability and its control of dip bedded soft rock slope in surface mines is one of the urgent technical problems in surface mining field. In shis thesis, with the southern slope of 1st mining area in Baiyinhua 1st Surface Mine as the engineering background, the deformation failure mechanism, three dimensional stability calculation method, three dimensional effect and control of stability, etc. of dip bedded soft rock slope are studied with the combination of field research, theoretical analysis, Limit Equilibrium Theory, continuum-based discrete element numerical simulation.Starting from the angle controlling the exposed length and time of slope and effectively improving the stability, the control mining technology that applies cross exploitation, inner dump tracking and burying slope is put forward. Based on the realization about the geological structure characteristics of slope and the spatial geometric form of potential sliding mass, the simplify mechanical model for the spatial sliding mass of the dip bedded soft rock slope is established, then based on the limit equilibrium theory, a new calculation method for the three-dimentional stability of the dip bedded soft rock slope is derived by geometric and mechanical analysis. Using the method and numerical simulation, the stability change rules of the dip bedded soft rock slope are compared and analyzed under different excavation position and spatial form conditions, then the tolerable exposed length of the layer and the slope angle of the southern slope of 1st mining area in Baiyinhua 1st Surface Mine are obtained, finally, the spatial form and parmers of the slope are determined under the condition of the control mining technology that applies cross exploitation, inner dump tracking and burying slope. By comparing and analyzing the distribution and evolution of the displacement and stress for different excavation and clean position, the superimposed effect of multiple weak layers on the slope deformaion and stability and the impact of cutting and unloading on the slope stability are revealed. By applicability analysis of all kinds of monitoring system, the slope monitoring project is set, then the graded warning mode with the displacement acceleration based on the realization about the displacement evolution of the typical landslides.