Ding Xiaohua, Yang Yuqing, Zhou Wei, An Wen, Li Jinyu, Ebelia Manda
School of Mines, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China.
School of Mines and Mineral Sciences, Copperbelt University, 21692, Kitwe, Zambia.
Sci Rep. 2022 Oct 12;12(1):17120. doi: 10.1038/s41598-022-22109-z.
The process of blasting stress wave propagation and crack propagation is directly affected by the physical properties of the rock mass and internal joints in the rock. In soft and hard rock layers, the blasting process is more complicated since the blasting stress wave needs to penetrate two kinds of rocks with different physical properties and the interface between soft rock and hard rock. In this study, the modal transformation of stress waves at the interface of layered composite rock was analyzed, and the process was reproduced by finite element analysis. Furthermore, the development law of cracks was explored. The research results demonstrated that in the single blasting-hole model, a triangular crack area caused by reflected stress waves appeared at the rock interface of rock medium I near the blast hole. In rock medium II, the tensile crack generated by the interface wave appeared on the side away from the blast hole. Besides, the development of the tensile crack was associated with the incident mode of the blast stress wave and the incident angle. In the deep hole blasting model, the incidence of the detonation wave front from hard rock to soft rock promoted the fragmentation of the hard rock.
爆破应力波传播和裂纹扩展过程直接受岩体物理性质及岩石内部节理的影响。在软硬岩层中，爆破过程更为复杂，因为爆破应力波需要穿透两种物理性质不同的岩石以及软岩与硬岩之间的界面。本研究分析了层状复合岩石界面处应力波的模态转换，并通过有限元分析对该过程进行了再现。此外，还探究了裂纹的发展规律。研究结果表明，在单炮孔模型中，靠近炮孔的岩石介质I的岩石界面处出现了由反射应力波引起的三角形裂纹区域。在岩石介质II中，界面波产生的拉伸裂纹出现在远离炮孔的一侧。此外，拉伸裂纹的发展与爆破应力波的入射方式和入射角有关。在深孔爆破模型中，爆轰波阵面从硬岩向软岩的入射促进了硬岩的破碎。
