Experimental and numerical investigations of dynamic failure process in rock under blast loading
Experimental and numerical investigations of dynamic failure process in rock under blast loading
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DOI：
10.1016/j.tust.2018.08.047
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发表时间：
2019-01-01
影响因子：
6.9
通讯作者：
Yang, Jun
中科院分区：
文献类型：
--
作者：
He, Chenglong;Yang, Jun
为研究不耦合装药条件下相邻炮孔间的动态破坏过程，对花岗岩样品进行了单孔和双孔爆破加载试验。采用高速摄像机(HS)和数字图像相关(DIC)方法获取应变场和裂纹扩展过程。实验结果表明，在单孔加载下，损伤沿中心孔呈对称分布，冲击波随离孔距离的增加而迅速衰减。在双孔加载下，损伤和塑性应变在二次加载下积累。二次加载使应力波叠加，两孔间形成径向裂纹。同时，在垂直方向上发现了双峰应变-时间曲线，表明没有形成弹性变形所产生的损伤。计算结果表明，两种载荷作用下的动力响应与试验结果吻合较好。解耦系数(K)为1时，井眼压力较大，然后随K的增大而线性减小。当K=2或5时，水平裂纹贯穿试件，垂直裂纹随着K的增加而线性减少。
For study the dynamic failure processes between adjacent boreholes with decoupling charge, the single-hole and double-hole blast loading experiments are set up with granitic samples. High-speed cameras (HS) and digital image correlation (DIC) methods are adopted to obtain strain field and crack development process. According to experimental results, the distribution of damage is symmetric around center hole under single-hole loading, shock wave falls off rapidly with increasing distance from the bore hole. Under double-hole loading, the damage and plastic strain are accumulated under second loading. The second loading makes the superposition of stress waves and the radial cracks formed between two holes. Meanwhile, the bimodal strain-time curve is found along vertical direction, and indicates the no damage is generated by elastic deformation is formed. According to the numerical results, the dynamic responses under two loads are agreed well with experimental results. The borehole pressure is much high when decoupling factors (K) is 1, and then linearly decreased with K increase. The horizontal cracks run through specimen as K = 2 similar to 5, and the vertical cracks linearly decrease with K increases.