(1. 北京科技大学土木与资源工程学院，北京 100083；
2. 金属矿山高效开采与安全教育部重点实验室，北京 100083)
摘 要: 为了研究不同养护龄期的分级尾砂胶结充填体在中等应变率动态冲击加载下的动力学特性，采用分离式霍普金森杆(SHPB)试验技术对16组48个充填体试样进行单次冲击实验。结果表明：充填体动态抗压强度和动态抗压强度提高因子随平均应变率的增大呈线性增长规律，而随养护龄期的延长，应变率敏感性呈减小趋势，动态抗压强度增幅则与冲击速度呈负相关；充填体的韧性指数随平均应变率的增加呈指数函数增长，且养护早期应变率敏感性更高、增幅更显著；充填体的吸收能、单位体积应变能(比能量吸收)与应变率、养护龄期均具有显著正相关性，且养护早期的能量值应变率敏感性更高、增幅更明显；动态冲击加载下，破坏形态主要为轴向拉伸破坏，且平均应变率越大、养护龄期越短，破坏越显著。
关键字: 充填体；应变率；养护龄期；动态强度；单位体积吸收能；破坏形态
（1. School of Civil and Resource Engineering, University of Science
and Technology Beijing, Beijing 100083, China;
2. Key Laboratory of High-Efficient Mining and
Safety of Metal Mines, Ministry of Education, Beijing 100083, China）
Abstract:In order to study the dynamic characteristics of graded tailings cemented backfill with different curing ages under medium strain rate dynamic impact loading, the split Hopkinson bar (SHPB) test technology was used to conduct single impact test on 48 backfill samples of 16 groups. The results show that the dynamic compressive strength and dynamic compressive strength improvement factor of backfill increase linearly with the increase of average strain rate. As the curing age increases, the strain rate sensitivity shows a decreasing trend, and the dynamic compressive strength increase is negatively correlated with the impact speed. The toughness index of backfill increases exponentially with the increase of average strain rate, and the strain rate sensitivity of early curing period increases. The absorption energy and strain energy per unit volume (specific energy absorption) of backfill have significant positive correlation with strain rate and curing age, and the sensitivity of energy value strain rate in early curing period is higher and the increase is more obvious. Under dynamic impact loading, the failure mode is mainly axial tensile failure, and the higher the average strain rate and the shorter the curing age, the more significant the damage.
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