Design of open pit coal mine slopes: An integrated approach

Many of the coal deposits of Western Canada exhibit intensely folded and/or faulted strata. Geological evaluation of such deposits is often difficult and uncertain, and interpretations are subject to significant modifications throughout the exploration, development and mining phases. Design and excavation of open pit slopes under such conditions can present a variety of operational and slope stability problems. Slope design approaches and excavation procedures which are flexible and capable of adapting to changing conditions are essential for rational slope development This paper examines the problems associated with open pit coal mine slope design in complex geologic environments. A systematic approach to slope design which incorporates engineering geology assessments, slope stability analyses, economic evaluations and mining operational constraints is presented:, Slope design concepts which utilize a variety of slope development techniques, Including benching and artificial support are developed. The design process continues throughout the mining phase in an iterative cycle whereby slope designs are prepared and implemented, remedial measures are applied, existing slopes are documented and evaluated, and slope design concepts and subsequent slope designs are updated and modified as necessary.