Blasting has been used extensively in deep underground excavation. In this paper, a numerical simulation LS-DYNA was carried out to investigate the influence of in situ stress and empty hole on rock fracture development. Based on the simulation process and existing laboratory data, the micromechanical properties of the Riedel-Hiermaier-Thoma (RHT) model were calibrated. By then, this model was used to study the effects of in situ stress and empty hole on the degree of damage and fracture development in the rock. Simulation results revealed that the difference between horizontal and vertical principal stresses can influence the degree of damage as well as the fracture initiation and development, which in turn leads to the fracture development towards a high-stress concentration area. Numerical simulation also showed that the total area of fracture development gradually decreases with the increasing in situ stress magnitudes. Under the same stress conditions, empty hole can facilitate the fracture development at 90°, while preventing the subsequent fracture development at 60° and 120°. This would result in further fracture propagation at 90°, such that the control of fracture direction can be achievable.

中文翻译：

---

空洞和原位应力对爆破岩石损伤影响的研究

爆破已广泛用于深层地下挖掘中。本文通过数值模拟LS-DYNA来研究原位应力和空洞对岩石裂缝发展的影响。基于仿真过程和现有实验室数据，对Riedel-Hiermaier-Thoma（RHT）模型的微机械性能进行了校准。届时，该模型将用于研究原位应力和空洞对岩石破坏程度和裂缝发展的影响。仿真结果表明，水平和垂直主应力之间的差异会影响破坏程度以及裂缝的发生和发展，进而导致裂缝向高应力集中区发展。数值模拟还表明，随着现场应力大小的增加，裂缝发展的总面积逐渐减小。在相同的应力条件下，空孔可促进90°裂缝的发展，同时防止随后在60°和120°裂缝的发展。这将导致裂缝进一步在90°传播，从而可以实现裂缝方向的控制。