【摘要】 地下洞室爆破开挖在动应力和地应力的共同作用下，将导致更为复杂的岩体破坏形式。本文基于二维动力损伤本构模型对不同静力条件下岩体动态破坏机制进行研究，探讨了不同围压和垂直应力系数K₀作用下动应力的加载速率和峰值对岩体动态变形破坏的影响。研究结果表明：数值模拟获得了爆破荷载作用下径向裂纹的萌生、扩展以及裂纹分叉、贯通的全过程，数值模拟的结果与相关物理试验结果保持一致；模拟了在不同动应力加载速率、加载峰值、垂直应力系数K₀和围压作用下岩石动态破坏全过程，结合应力场、声发射、破坏图像与受力机理，分析了不同加载条件下裂纹的产生机理；非均匀性对裂纹扩展影响很大，相对于非均质性更强的岩石试样，主裂缝裂纹扩展路径呈现出很明显的拐折、不连续的特点，破裂过程呈现弥散性，反映了试样内部应力分布复杂。更多还原

【Abstract】 When underground cavities are subjected to explosive stress waves, a uniquely damaged zone may appear due to the combined effect of dynamic loading and static pre-load stress. In this study, a rate-dependent two-dimensional rock dynamic constitutive model was established to investigate the dynamic fractures of rocks under different static stress conditions. The effects of the loading rate and peak amplitude of the blasting wave under different confining pressures and the vertical compressive coefficient（K₀） were considered. The numerical simulated results reproduced the initiation and further propagation of primary radial crack fractures, which were in agreement with the experimental results. The dynamic loading rate, peak amplitude, static vertical compressive coefficient（K₀） and confining pressure affected the evolution of fractures around the borehole. The heterogeneity parameter（m） plays an important role in the evolution of fractures around the borehole. The crack propagation path became more discontinuous and rougher in a smaller-heterogeneity parameter case.更多还原