The Rock Slope Stability Assessment And Dynamic Analysis At Cape Lambert Open-pit

The depletion of shallow-face mineral resources and price rise of mineral products have made it possible to exploit low grade ore which originally was not worth exploitation. As a result, the scale and depth of open pits are being continuously expanded, from whose collapse accidents are continuously increasing. How to ensure both mining safety and economic benefits is an urgent issue for current slope design and treatment. With Cape Lambert Open-pit Iron Mine as a research object, this thesis analyses slopes in the respects of the slope stability evaluation, optimization of slope angle and slope stability analysis, and completes the following tasks.-(1) Reviews the major methods for slope rock mass quality rating, and distinguishes the slope stability assessment from rock mass quality rating. Analyzes and categorizes the factors which influence slope stabilization, after which this thesis sets up another slope stabilization assessment method based on considering geological conditions, natural environment and engineering design, etc.(2) Optimizes the slope gradient for slopes that have been evaluated and found optimizable. In view of the fact that the research target requires both slope stability analysis and gradient optimization, numerical simulation method is adopted to calculate the potential dip angles of the sliding face, then the limit equilibrium method is used to calculate safety factors respect to different slope gradients, and finally the optimized slope angle that meets the safety threshold value is selected.(3) Analyse the stabilization under seismic conditions for slopes which have potential failure conditions, thus make clear the stress distribution in the potential sliding faces under static and dynamic loads. During calculate dynamic safety factors under earthquake load, the "disturbance" effect of stress transmission is put forward. On basis of this, the calculation for sliding mass acceleration time history is researched, and quasi-static method is referred to calculate the safety factor time-history.