Abstract：
During the excavation of underground projects, the rock masses left as the bearing support system are also subjected to dynamic loads from the excavation activities ahead. These rock masses have been damaged and fractured during the initial exposure (dynamic loads) and are subjected to static loads in the subsequent process as the support system. In this study, granite rock samples and specimens with different angles were produced, preloaded with different confining pressure, and under a combination of dynamic and static loading tests using a modified dynamic and static loading system: split Hopkinson pressure bar (SHPB). The peak strain and dynamic modulus of elasticity are weakened by the inclination angle in a similar way to the strength, with the specimens showing an evolutionary pattern from tensile strain to shear damage. The change in the inclination angle of flaws would weaken the dynamic and combined strengths, and a larger inclination flaw results in a significant decrease in its strength. Fractal analysis revealed that the fractural dimension was closely related to the fissure angle and showed a good linear correlation with the strain rate. This study will provide an important security assurance for deep mining.
摘要：
在地下工程开挖过程中,作为轴承支撑系统留下的岩体也受到来自前方开挖活动的动态载荷。这些岩体在初始暴露（动态载荷）期间已被破坏和破裂，并在后续过程中作为支撑系统承受静态载荷。在这项研究中,制作了不同角度的花岗岩岩石样品和标本，预装不同围压，在动态和静态加载测试的组合下，使用改进的动态和静态加载系统：分离式霍普金森压杆（SHPB）。峰值应变和动态弹性模量以类似于强度的方式被倾角削弱，标本显示出从拉伸应变到剪切损伤的演化模式。缺陷倾角的变化会削弱动态和综合强度，和较大的倾斜缺陷导致其强度显著降低。分形分析表明，裂隙维数与裂隙角密切相关，与应变率呈良好的线性关系。该研究将为深部开采提供重要的安全保障。
