We intercompare highly constrained physical experiments with a three-dimensional bonded-particle discrete element model. The models incorporate a single inclined rough joint at various inclinations to simulate the mechanical response of fractured-rock from micro-scale cracking through crack-coalescence and culminating in macro-scale rupture. This approach combines the scanned 3D surface morphology of the real joints with a smooth-joint contact DEM model to overcome the problem of using a simplified geometry that cannot truly reflect the effects of joints on rock mass response. In both the physical samples and in the modeling, the inclination angle of the joint was varied between 0° and 50°, and the samples were tested under confining stresses in the range 0–40 MPa. The numerical test results indicate that: (1) confining stress has a significant strengthening effect on the jointed sandstone; (2) a threshold angle of ~ 40° of the inclined joint controls failure; (3) when the inclination angle is less than ~ 40°, failure is through the intact rock with some tensile fracturing around the joint and when greater than ~ 40° slip occurs on the joint with shear fracturing concentrated near the joint surface; (4) the 3D numerical approach replicates the deformation history and evolving texture of the jointed sample response with high fidelity, including the evolution of micro-scale features of progressive failure. The three-dimensional bonded-particle discrete element modeling represents a systematic verification of, and extension to, laboratory tests, presenting a viable model to emulate the mechanical behavior of jointed rocks with the potential to enhance the predictive capability of modeling while still maintaining reasonable computational efficiency.

中文翻译：

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含斜粗节理砂岩晶粒尺度力学行为的三维数值模拟

我们将高度受限的物理实验与三维键合粒子离散元素模型进行比较。这些模型结合了不同倾斜度的单个倾斜粗糙节理，以模拟裂缝岩石从微观开裂到裂缝合并并最终导致宏观破裂的力学响应。这种方法将扫描的真实节理的 3D 表面形态与平滑节理接触 DEM 模型相结合，以克服使用简化几何无法真实反映节理对岩体响应的影响的问题。在物理样品和建模中，接头的倾角在 0° 和 50° 之间变化，样品在 0-40 MPa 的围压下进行测试。数值试验结果表明：(1)围压对节理砂岩有显着的强化作用；(2) 倾斜关节控制失效的~40°阈值角；(3) 当倾角小于～40°时，破坏是通过完整的岩石，节理周围有一些拉伸裂缝；当大于～40°的滑移发生在节理上时，剪切裂缝集中在节理面附近；(4) 3D 数值方法以高保真度复制了连接样本响应的变形历史和演化纹理，包括渐进失效的微观特征的演化。三维粘结粒子离散元建模代表了对实验室测试的系统验证和扩展，