This study is based on indoor experiments using PFC2D to conduct numerical tests on the uniaxial compression of layered rock masses with multiple sets of parallel rough joints at a loading rate of 0.1 m/s. The layered rock mass is composed of hard matrix and weak interlayer, with uniaxial compressive strengths of 45.43 MPa and 16.08 MPa and elastic moduli of 4.47 GPa and 3.20 GPa, respectively. This study numerically investigated the influences of bedding inclination α (0°–90°), joint roughness coefficient JRC (0–19.55) and anchor bolts on crack propagation, fracturing responses, crack initiation stress, mechanical properties, ultimate failure modes, and brittleness index for the rough layered rock mass. The results show that, with an increasing bedding inclination, the peak strength of the layered samples exhibits a “U”-shaped variation trend, first decreasing and then increasing. For the bedding inclination = 30°–75°, the peak strength increases with an increasing JRC. The failure modes of the sample are mainly influenced by the bedding inclination. For the bedding inclination = 0°–30° and 90°, the samples mainly experience tensile splitting failure. For the bedding inclination = 45°–75°, the samples undergo shear slip failure along the weak interlayer. The crack initiation stress of the layered samples first decreases and then increases with an increasing bedding inclination and increases with an increasing JRC. The peak strength and failure mode of the samples are both functions of the bedding inclination and JRC. Based on the different failure modes, a nonlinear strength failure criterion for the layered rock masses with multiple sets of parallel rough joints is established. Comparison with the experimental results shows that this criterion can better reflect the mechanical properties of layered rock masses. Anchor bolts can effectively increase the peak strength, reduce the brittleness characteristics, and restrict the shear slip deformation for the samples. The peak strength increases by 18.03–26.21% with an increasing initial anchoring force (0–20 MPa). When the anchoring force is 10 MPa, the peak strength of the anchored samples decreases first and then increases regarding the bedding inclination. Compared with the unanchored samples, the peak strength increases by 9.44–42.13% and the brittleness index decreases by 18.58–72.44%. The peak strength of the anchored samples increases with JRC. Compared with unanchored samples, the peak strength increases by 14.72–26.21%, while the brittleness index decreases by 69.05–73.19%.

本研究基于室内实验，利用PFC2D对具有多组平行粗糙节理的层状岩体进行单轴压缩数值试验，加载速率为0.1 m/s。层状岩体由硬基质和软弱夹层组成，单轴抗压强度分别为45.43 MPa和16.08 MPa，弹性模量分别为4.47 GPa和3.20 GPa。本研究数值研究了层理倾角α（0°–90°）、接头粗糙度系数JRC（0–19.55）和锚栓对裂纹扩展、断裂响应、裂纹萌生应力、力学性能、最终失效模式和脆性的影响粗糙层状岩体的指数。结果表明，随着层理倾角的增大，层状样品的峰值强度呈现先减小后增大的“U”型变化趋势。对于层理倾角 = 30°–75°，峰值强度随着 JRC 的增加而增加。试件的破坏模式主要受层理倾角的影响。当层理倾角=0°~30°和90°时，样品主要发生拉伸劈裂破坏。当层理倾角= 45°–75°时，样品沿弱夹层发生剪切滑移破坏。层状样品的裂纹萌生应力随着层理倾角的增大先减小后增大，并随着JRC的增大而增大。样品的峰值强度和破坏模式都是层理倾角和 JRC 的函数。根据不同的破坏模式，建立了多组平行粗糙节理层状岩体的非线性强度破坏准则。与试验结果对比表明，该判据能较好地反映层状岩体的力学特性。锚栓可以有效提高试样的峰值强度，降低脆性特征，限制试样的剪切滑移变形。随着初始锚固力（0-20 MPa）的增加，峰值强度增加18.03-26.21%。当锚固力为10 MPa时，锚固样品的峰值强度随层理倾角先减小后增大。与未锚固样品相比，峰值强度提高了9.44%~42.13%，脆性指数降低了18.58%~72.44%。锚定样品的峰值强度随着 JRC 的增加而增加。与未锚固样品相比，峰值强度提高了14.72%~26.21%，而脆性指数降低了69.05%~73.19%。