Evaluation of Grouting Reinforcement Effectiveness in Coal Seam Floors Using the Monte Carlo Analytical Hierarchy Process: A Case Study of the Rongkang Coal Mine.

Pregrouting reinforcement of the coal seam floor is an effective measure for preventing floor water hazards. However, how to objectively evaluate the grouting effectiveness using data from drilling and grouting construction processes remains an urgent issue that needs to be addressed. Based on the coal seam floor grouting project at the Rongkang Coal Mine in Shanxi Province, this study developed a comprehensive evaluation index system for assessing the effectiveness of coal seam floor grouting, consisting of six evaluation indicators. This study employs the Monte Carlo Analytic Hierarchy Process (MAHP) to calculate the weights of the evaluation indicators. By incorporation of probability distributions and stochastic simulations, this method enhances the traditional Analytic Hierarchy Process (AHP), improving the objectivity and scientific rigor of the indicator weighting process. A comprehensive evaluation model for coal seam floor grouting effectiveness was developed using GIS and MAHP. This model enables the generation of thematic maps illustrating the spatial distribution of grouting reinforcement effectiveness. Based on borehole water inflow measurements obtained after grouting at the 10102 working face of the Rongkang Coal Mine, zoning criteria were established to classify the grouting effectiveness map into three zones: poor, qualified, and good. The evaluation model developed in this study was applied to assess the effectiveness of floor grouting reinforcement at workfaces 10102, 10103, and 10106, and the evaluation results were compared with actual grouting outcomes from field measurements. The comparative analysis showed a high degree of consistency between the model predictions and the actual field conditions, validating the reliability of the model. The proposed model can serve as a scientific reference for evaluating the effectiveness of coal seam floor grouting reinforcement in mines under similar geological conditions.