Goaf has become one of the most significant sources of hazard affecting the safety of metal and nonmetal mines. Evaluation of goaf stability is of paramount importance for mine safety production. First, 13 indices such as rock mass structure, geological structure, and goaf volume are selected based on engineering experience and literature review to assess the stability of goaf. These indices are classified according to the characteristics of each factor, and a stability evaluation system for underground mine goaf is constructed. Second, the analytic hierarchy process method based on group decision theory is utilized to calculate the subjective weight of each index. Additionally, the CRITIC method is used to calculate the objective weight of each index. Finally, game theory is used to combine the subjective and objective weights, thereby improving the accuracy of the index weight. The stability grade of the goaf is calculated using the normal cloud model. The FLAC3D numerical simulation is used to analyze the stability of the goaf and verify the accuracy of the model. The abovementioned model is utilized for assessing the stability of the goaf in the Duimenshan mine section. The results indicate that 90% of the goaf area is in a stable or relatively stable condition, while the remaining 10% is unstable. The evaluation outcomes were compared with FLAC3D numerical simulations, highlighting a scientific and reliable method with an accuracy rate of 90%.

To effectively mitigate the hazards posed by the blast waves of rock mass caving on closed walls during the mining process, a stability prediction method based on a random forest (RF) algorithm is proposed, which is designed to automatically identify key parameters. A machine learning model is developed using the algorithm, and its performance is evaluated through accuracy, precision, recall, and F1-score metrics. The probabilistic model of the objective function is constructed using the grid search hyperparameter optimization method, allowing for the selection of the most favorable hyperparameters for evaluation. The initial prediction accuracy of the RF algorithm model is 94.6%, indicating a strong predictive capability. Further adjustments to the base classifier, maximum depth, minimum number of leaves, and minimum number of samples enhance the model’s performance, resulting in an improved prediction accuracy of 95.9%. Finally, the optimized model is applied to predict the stability of the closed walls in the actual project, and the results are consistent with the on-site situation. This demonstrates that the random forest-based stability prediction model effectively forecasts the stability of closed walls in the actual project.

The accurate prediction of roof stress in mined-out areas is crucial for ensuring mine safety. However, existing study methods often overlook the increasingly available image data and fail to balance the model predictive capability with interpretability. To address these issues, this study innovatively integrates 3D laser scanning image features into the prediction of roof stress in mined-out areas. Image features are extracted using pre-trained deep-learning models and combined with traditional geological parameters to construct multiple machine-learning models for prediction. The experimental results demonstrate that models incorporating image features significantly outperform traditional models that rely solely on geological parameters in terms of prediction accuracy, interpretability, and complexity, revealing the critical role of image features in stress prediction. Furthermore, the use of SHapley Additive exPlanations (SHAP) to interpret the random forest model uncovers new domain knowledge, such as the relationship between spatial patterns and stress concentration. This study theoretically validates the effectiveness of image data and effectively balances the predictive capability and interpretability of the model, facilitating knowledge discovery in the field. On a practical level, it also provides guidance for mine safety management.

The double‐layer goafs are commonly found in mines that use the open stope mining method. The mechanical characteristics of the isolated roof in the double‐layer goaf column directly affect the safety of the double‐layer goaf and its surrounding goafs and have a greater impact on the safety of mine production. Taking the Bainiuchang Silver Mine as the engineering background, a mechanical model of the ends‐fixed beam of the double‐layer goaf isolation roof with the upper and lower goafs overlapping completely is established. Then, the stress and displacement components of the isolated roof are deduced by using the Airy stress function, which introduces the boundary condition of a fixed end that both considered the restriction of ∂ v / ∂ x and ∂ u / ∂ y on the rotation of the rigid body. The results of three‐dimensional surface and contour show that the maximum stress and displacement of the isolated roof are distributed in different regions of the roof, and the corresponding stress characteristics include shear, compression, and tension. Considering that the thickness of the isolation roof and the overlying load have a great influence on the stress and displacement of the roof, use the controlled variable method to study the influence of both on the maximum stress and displacement of the isolation roof. The results show that the smaller the thickness of the isolated roof depended on the stoping progress of the lower middle, the larger the increase of the stress and displacement components except the maximum vertical stress component. The maximum horizontal stress and the maximum vertical displacement increase greatly when the overburden of the isolated roof depends on the stoping progress of the upper middle. Therefore, in the actual engineering, the thickness of the safety pillars should be reasonably arranged, and at the same time, the stress concentration and vertical displacement changes at both ends of the isolation roof should be paid particular attention.