Operating risk: Planning for flexible mining systems.

摘要

This research contributes to understanding the interaction between ground-related problems and mining systems as a basis for the development of flexible mining systems. It has demonstrated that ground-related problems impose a significant operating risk factor that requires particular attention in proactive mine planning and design. A new philosophy for quantifying the impact of ground-related problems and assessing the links between mine planning and geomechanics was established. The various types of potential problems were classified based on review of case studies and the surveillance of ground failures in several underground hard rock mines of the Sudbury Basin. It was demonstrated that, despite serious efforts in the design of underground mines, ground-related problems still cannot be totally avoided.; A time-dependent internal risk model was established to quantify the impact of ground-related problems in mine production systems. Subjective probabilities provide the input for a reliability analysis, which derives the required input parameters for production simulation. Reliability analyses that are currently used to calculate the reliability of mine equipment were applied for the case of mine subsystems with ground-related problems. A cost impact model that is dependent on the parameters determined in a reliability analysis was introduced.; Flexibility needs in mine planning and design, with respect to ground-related problems, were analyzed through conventional discounted cash flow analysis, real options analysis, production simulation, and Monte-Carlo simulation. Approaches that are currently applied in investment science and decision making were evaluated in terms of their applicability to evaluate such flexibility needs in mining systems. A methodology that includes the applicability of project valuation analyses to assess flexible mining systems with respect to potential ground-related problems, along with a flexibility index, were introduced. Their applicability is demonstrated through test case studies. Contingency planning and flexibility assessment by such means can be integrated into future mine production systems to account for the potential risk of ground-related problems for more proactive mine planning and design.