动载下石灰岩能耗指标影响因素研究*

为研究石灰岩在动载破坏过程中的能量耗散，基于Φ50 mm的霍普金森压杆系统，对石灰岩开展三轴动静加载冲击试验，深入分析入射能、反射能、透射能、耗散能、能耗率与轴压、围压、应变率（冲击气压）之间的关系，并借助灰色关联理论分析石灰岩围压、应变率、纵波波速与能耗特征的关联。研究结果表明:入射能和耗散能均与应变率呈正向增长趋势，且耗散能应变率相关性更强；能耗率与围压呈反向增长趋势，低围压条件有利于石灰岩的破碎；能耗程度与冲击气压、围压、纵波波速的关联度分别为0.729 9，0.705 4，0.581 5，围压和冲击气压的灰色关联度大于0.6，因此围压和冲击气压对石灰岩能量耗散特征有显著影响。研究结果对于喀斯特地貌石灰岩爆破施工具有重要的参考价值。

Study on influencing factors of energy consumption index of limestone under dynamic load

In order to study the energy dissipation of limestone in the process of dynamic load failure,the triaxial dynamic and static loading impact tests of limestone were carried out by using the Φ50 mm Hopkinson pressure bar system.The relationship between the incident energy,reflection energy,transmission energy,dissipation energy,energy consumption rate and the axial pressure,confining pressure and strain rate (impact gas pressure) was analyzed,and the grey correlation theory was used to analyze the correlation between confining pressure,strain rate ,longitudinal wave velocity and energy consumption characteristics of limestone.The results showed that both the incident energy and dissipation energy had a positive growth trend with strain rate,and the correlation between dissipation energy and strain rate was stronger.The energy consumption rate increased inversely with the confining pressure,and the low confining pressure was beneficial to the limestone crushing.The correlation degree of energy consumption with impact gas pressure,confining pressure and longitudinal wave velocity was 0.729 9,0.705 4 and 0.581 5,respectively,and the grey correlation degree between confining pressure and impact gas pressure was greater than 0.6.So the confining pressure and impact gas pressure had significant influence on the energy dissipation characteristics of limestone.The research results have important reference value for limestone blasting construction in karst landform.