Drop Hammer Impact Test on Concrete Well Walls After Combined Action of Compressive Load and Sulfate Erosion

The long-term safety of concrete shaft walls in deep mines faces severe challenges from the coupled effects of stress, chemical erosion, and dynamic disturbances. This study conducted coupled loading and sulfate erosion tests on concrete and investigated its dynamic response using drop-weight impact tests. The failure modes, impact force time-history curves, and strain time-history curves of concrete under different erosion ages and load levels were analyzed. The SEM observations revealed the microstructure of the concrete. Results indicate that increasing drop height exacerbates specimen failure and elevates peak impact force and strain, while simultaneously shortening the impact duration. Compared to SL20, SL40 exhibited lower peak impact force and higher peak strain under long-term combined loading and sulfate erosion. This reveals that larger loads accelerate internal damage within concrete under erosive conditions. This study provides theoretical and experimental bases for the long-term safety and impact resistance of well wall concrete.