Study on the evaluation of workface wall stability based on cloud model

To address the uncertainty and fuzziness during conventional workface rib spalling prediction, a rating system of workface wall stability considering subjective experience factor, mechanical performance of coal mass, workface production condition, and support/surrounding rock coupling was constructed, fuzzy factors such as the number of cracks, crack distribution, and feedback of wall/roof tapping were analyzed systematically and quantitatively based on the long-term inspection experience of coal mine safety inspectors, and rating criteria of workface wall stability were established; the AHP-CRTIC-Game Theory integrated weighting method was used to determine the optimized overall weight. Additionally, the normal cloud model was used to determine the workface wall stability level. The application of this model in the Workface 25,221 of a mine in Xinjiang, China revealed that the workface wall stability was at Level III, suggesting an unstable condition, which was consistent with the on-site observations. This verified the scientificity and validity of the proposed model. This study not only provides a new approach of analyzing workface wall stability but also offers theoretical references and technical support for coal mine safety management and wall stability.