Application of fuzzy comprehensive assessment and rock engineering system to assess cavability in block caving mining and establishment of its regionalized model

The assessment of rock mass cavability is a key research topic when mines intend to adopt block caving mining during the feasibility stages. However, cavability assessment is a multi-index and non-linear complex process in system engineering, and uncertainty exists in the assessment process. In this situation, it is important for cavability assessments to minimize the subjectivity of human judgements and consider the factors that influence cavability and their interrelationships. In this study, we introduce a new approach that combines fuzzy comprehensive assessment (FCA) with rock engineering system (RES). First, the FCA was applied to establish an assessment model based on a conversion function, membership function, and fuzzy assessment matrix. Second, the RES was used to determine the weights of influential factors by applying an interaction matrix. Third, rock mass cavability was analysed based on the assessment model and the factor weights. The results of the cavability assessment were for a partial rock mass due to the discontinuity of the cavability assessment index value in space. Therefore, geostatistics and block models were adopted to establish a regionalized model of rock mass cavability, and the spatial distribution of cavability was obtained. Based on the Luoboling copper-molybdenum mine as a case study, FCA and the RES were applied, and a regionalized model of cavability was established. The results can provide a basis for studies of block caving mining and mine design.