【摘要】 针对保留围岩在爆炸荷载下的稳定性问题，基于SHPB、二波分析和分形理论等，对不同应变率加载下云南某矿区结晶灰岩的应力-应变曲线、破碎形态、分型维数及能量耗散特性开展相关研究。试验结果表明：应变率为49.64 s^-1时，岩石试件破坏模式主要为轴向劈裂破坏；应变率为87.05 s^-1时的破坏模式为劈裂-剪切组合破坏；在动态抗压强度方面，随着应变率的增加岩石的动态抗压强度与之呈明显的线性正相关关系，与静态抗压强度相比，动态强度增长因子由1.19增长至2.86;随着应变率增加，分形维数表现出逐渐增大的规律，应变率在30.37～138.18 s^-1时，D_f值从1.96增加至2.23,但随着应变率的增加D_f最终趋于某一阈值；耗能密度随入射能量呈指数增长。研究结果提供了不同应变率冲击荷载下结晶灰岩的动态破碎和耗能规律，为此类矿区安全高效的爆破施工及类似工程设计提供依据。更多还原

【Abstract】 Aiming at the stability of retained surrounding rock under blasting load, based on SHPB, two-wave analysis and fractal theory, the stress-strain curve, fragmentation morphology, classification dimension and energy dissipation characteristics of crystalline limestone in a mining area of Yunnan under different strain rate loading were studied. The test results show that the failure mode of rock specimens is mainly axial splitting failure when the strain rate is 49.64 s^-1, and the failure mode is splitting-shear combination failure when the strain rate is 87.05 s^-1. In terms of dynamic compressive strength, with the increase of strain rate, the dynamic compressive strength of rock has a significant linear positive correlation with it. Compared with the static compressive strength, the strength factor increases from 1.19 to 2.86; with the increase of strain rate, the fractal dimension showed a gradual increase. When the strain rate was 30.37～138.18 s^-1, the D_f value increased from 1.96 to 2.23, but with the increase of strain rate, D_f finally tended to a certain threshold. The energy density increases exponentially with the incident energy. The research results provide the dynamic crushing and energy dissipation law of crystalline limestone under different strain rate impact loads, and provide a basis for safe and efficient blasting construction and similar engineering design in such mining areas.更多还原