Abstract Unloading can cause many geotechnical disasters, e.g., the rock burst. The underlying mechanism of rock failure is the propagation and coalescence of cracks. To get insight into rock unloading failure, the discretized virtual internal bond (DVIB) model in conjunction with element partition method (EPM) is used to simulate the dynamic fracturing process under unloading conditions. At first, the samples with the single flaw are simulated under unloading conditions. It is found that the fracturing pattern exhibits the tensile-shear transition with the initial stress level increasing. When the flaw inclination is closer to 45 degree or the flaw is longer, shear cracks are more likely to occur. Then, the unloading failure process of rock with multiple flaws are simulated. It is found that the inclination of the parallel flaws has remarkable influence on the unloading failure of rock. When the inclination angle is about 45 degree, the rock is easier to fail. For the rock with multiple randomized flaws, the amount of flaws has slight influence on acoustic emission counts. However, the configuration of randomized flaws can significantly affect the fracture process and failure patterns. These findings can improve understanding of rock burst and provide valuable references for the prediction of unloading failure of rock.

中文翻译：

---

突然卸荷条件下裂隙岩动态压裂过程数值研究

摘要 卸荷会引起许多岩土灾害，如岩爆。岩石破坏的潜在机制是裂缝的扩展和合并。为了深入了解岩石卸载失败，离散虚拟内键（DVIB）模型结合单元划分方法（EPM）用于模拟卸载条件下的动态压裂过程。首先，在卸载条件下模拟具有单个缺陷的样品。发现随着初始应力水平的增加，压裂模式呈现出拉伸-剪切转变。缺陷倾角越接近45度或缺陷越长，越容易产生剪切裂纹。然后，模拟了多裂纹岩石的卸载破坏过程。发现平行缺陷的倾斜度对岩石的卸载破坏有显着影响。当倾角在45度左右时，岩石更容易破裂。对于具有多个随机缺陷的岩石，缺陷的数量对声发射计数的影响很小。然而，随机缺陷的配置会显着影响断裂过程和失效模式。这些发现可以提高对岩爆的认识，为岩石卸荷破坏的预测提供有价值的参考。随机缺陷的配置可以显着影响断裂过程和失效模式。这些发现可以提高对岩爆的认识，为岩石卸荷破坏的预测提供有价值的参考。随机缺陷的配置可以显着影响断裂过程和失效模式。这些发现可以提高对岩爆的认识，为岩石卸荷破坏的预测提供有价值的参考。