Evaluation Model of Hard Limestone Reformation and Strength Weakening Based on Acidic Effect

The typical thick-hard limestone roof with high failure pressure and easy fracture closure under in situ stress is extremely prone to induce disasters, which seriously threatens the safe production of coal mines. modification carbonate minerals by acidic effects can effectively realize weakening control hard strata. In this study, a multi-factor orthogonal experiment was designed for acidification reactions, evaluation model reformation strength based on effect established accordingly. results showed that there an order influence various factors reaction parameters indices acidified limestone, improvement rock properties level difference acid concentration significantly better than type time. Through numerical analysis, considering given. reliability passed credibility test experimental verification, reflect response characteristics limestone. simulated annealing (SA) algorithm introduced derive optimal system suitable weakening. Combined model, mechanism strata analyzed. not only rapid generation expansion micro-cracks at mineral-containing crystal defects, but also make cracks remain relatively open due differential interaction mineral components, conducive bearing capacity reduction structural damage mass. research provide theoretical guidance underground