In order to obtain the relationship between fractal dimension and energy dissipation of rock-like materials under initial stress state, a variable cross-section split Hopkinson pressure bar (SHPB) test system with active confining pressure loading device was used to carry out impact compression and splitting tests on cemented sand specimens. The impact test results show that (1) the prediction value on the fragmentation degree of cemented sand specimens by using the fractal model is basically consistent with the screening results of actual test, which verifies the applicability of the fractal calculation model given in this study; (2) the more the fracture energy dissipated in the crushing process of cemented sand specimens, the more serious the fragmentation degree is, and accordingly the larger the fractal dimension is, that is, the fracture energy is positively correlated with the fractal dimension; (3) there is an exponential relationship between the fractal dimension and energy dissipation of cemented sand specimens under initial stress, which is so different from that under no initial stress. The experimental results in this study can be used to modify the fractal damage model for rock blasting considering the initial stress.

中文翻译：

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初始应力下岩石碎裂度的分形维数与能量耗散的关系

为了获得岩石材料在初始应力状态下的分形维数与能量耗散之间的关系，采用带有主动约束压力加载装置的变截面裂口霍普金森压力杆（SHPB）测试系统进行冲击压缩和压缩。水泥砂样的劈裂试验。冲击试验结果表明：（1）使用分形模型预测的胶结砂土碎裂程度预测值与实际试验的筛选结果基本吻合，验证了本研究给出的分形计算模型的适用性；（2）在胶结砂土试样的破碎过程中，断裂能耗散的越多，破碎程度越严重，因此分形维数越大，即 断裂能与分形维数呈正相关。（3）初始应力下水泥砂样的分形维数与能量耗散之间存在指数关系，与没有初始应力下的分形维数和能量耗散之间存在指数关系。考虑到初始应力，本研究中的实验结果可用于修改岩石爆破的分形破坏模型。