Long-term mechanical behavior and characteristics of cemented tailings backfill through impact loading

摘要

Cemented tailings backfill (CTB) structures are important components of underground mine stopes. It is important to investigate the characteristics and dynamic behavior of CTB materials because they are susceptible to disturbance by dynamic loading, such as excavation and blasting. In this study, the authors present the results of a series of Split-Hopkinson pressure bar (SHPB) single and cyclic impact loading tests on CTB specimens to investigate the long-term dynamic mechanical properties of CTB. The stress-strain relationship, dynamic strength, and dynamic failure characteristics of CTB specimens are analyzed and discussed to provide valuable conclusions that will improve our knowledge of CTB long-term mechanical behavior and characteristics. For instance, the dynamic peak stress under cyclic impact loading is approximately twice that under single impact loading, and the CTB specimens are less prone to fracture when cyclically loaded. These findings and conclusions can provide a new set of references for the stability analysis of CTB materials and help guide mine designers in reducing the amount of binding agents and the associated mining cost.