In nature, some flaws (such as fissures, joints, weak surfaces, and faults, etc.) are pre-existed in the rock masses, which have been proved an important influence on the mechanical properties of rock masses. In this paper, a three-dimensional (3D) joint model of a fractured specimen is built by means of the computed tomography (CT) scanning technic and digital image processing. The model shows three joints exist in the specimen: an essential joint which can be found from the specimen surface and two extra-essential joints can only be detected from the 3D joint model. The 3D joint model is integrated into 3D particle flow code (PFC^3D) to build a jointed numerical specimen and triaxial compression tests under different confining pressures are simulated. The results show that the linear phase of the stress-strain curve is more significant under larger confining pressure. The peak strength of the jointed specimen increases linearly with the confining pressure. In addition, the peak strength of the jointed specimen shows highly consistency with the residual strength of the corresponding intact specimen. For both the intact and jointed specimen, Young's modulus increases nonlinearly with the confining pressure, and remains constant after confining pressure reaching 20 MPa.

中文翻译：

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常规三轴压缩下节理岩石试件三维模型重建与数值模拟

在自然界中，岩体中预先存在一些缺陷（如裂隙、节理、薄弱面、断层等），已被证明对岩体的力学性质有重要影响。本文采用计算机断层扫描（CT）扫描技术和数字图像处理技术，建立了断裂试样的三维（3D）关节模型。该模型显示试样中存在三个接头：一个可以从试样表面找到的基本接头和两个额外的基本接头只能从 3D 接头模型中检测到。3D关节模型集成到3D粒子流代码（PFC ^3D) 建立关节数值试件并模拟不同围压下的三轴压缩试验。结果表明，围压越大，应力-应变曲线的线性相位越显着。节理试样的峰值强度随围压线性增加。此外，连接试样的峰值强度与相应完整试样的残余强度高度一致。对于完整试样和节理试样，杨氏模量均随围压非线性增加，并在围压达到20 MPa后保持不变。