Quantification of fault uncertainty and risk assessment in longwall coal mining: stochastic simulation,back analysis,longwall design and reserve risk assessment

Abstract

A method for fault uncertainty and risk assessment based on the concept of stochastic simulation is presented herein. The method is applied and back-analysed using the data from mined out longwall panels at North Goonyella Mine (Queensland, Australia). The results from the case study and its back-analysis show that one, fault risk can be quantified and two, this quantified fault risk can be integrated into longwall design and assist decision making. A third observation is that basing fault risk assessment on known faults alone underestimates fault risk and as a result, its quantification through simulation has a major positive economic impact. A fourth and final observation is that fault risk quantification supports the evaluation of mineable coal reserves: a risk comparison of mined out coal seams with other areas allows for the comparison of different levels of quantified risk for a comparable longwall design. The study shows the contribution of the quantified risk approach to reducing coal mining investment risks due to faults, as well as facilitating more informed decisions.