To study the characteristics of rock fracture in deep underground under blast loads, some numerical models were established in AUTODYN code. Weibull distribution was used to characterize the inhomogeneity of rock, and a linear equation of state was applied to describe the relation of pressure and volume of granite elements. A new stress initialization method based on explicit dynamic calculation was developed to get an accurate stress distribution near the borehole. Two types of in situ stress conditions were considered. The effect of heterogeneous characteristics of material on blast-induced granite fracture was investigated. The difference between 2D models and 3D models was discussed. Based on the numerical results, it can be concluded that the increase of the magnitude of initial pressure can change the mechanism of shear failure near the borehole and suppress radial cracks propagation. When initial lateral pressure is invariable, with initial vertical pressure rising, radial cracks along the acting direction of vertical pressure will be promoted, and radial cracks in other directions will be prevented. Heterogeneous characteristics of material have an obvious influence on the shear failure zones around the borehole.

中文翻译：

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爆炸应力波诱发深部花岗岩断裂特征的数值研究

为研究爆炸荷载作用下深部地下岩石的破裂特征，在AUTODYN程序中建立了一些数值模型。威布尔分布用于表征岩石的不均匀性，并应用线性状态方程来描述花岗岩单元的压力与体积的关系。开发了一种基于显式动态计算的新应力初始化方法，以获得井眼附近的准确应力分布。考虑了两种类型的原位应力条件。研究了材料的异质特性对爆破花岗岩断裂的影响。讨论了 2D 模型和 3D 模型之间的区别。根据数值结果，可以得出结论，初始压力大小的增加可以改变钻孔附近的剪切破坏机制，抑制径向裂缝的扩展。当初始侧压力不变时，随着初始竖向压力的升高，沿竖向压力作用方向的径向裂纹将得到促进，防止其他方向的径向裂纹。材料的非均质特性对钻孔周围的剪切破坏带有明显的影响。