Rock bolts have been widely used in slopes as a reinforcement measure. Modelling the shear mechanical behaviours of bolted rock joints is very complicated due to the complex factors that affect the axial force and shear force on the bolts. Rock bolts under shear action exhibit the guide rail effect; that is, the rock mass slides along the rock bolt as if the rock bolt is a rail. The normal stress can inhibit the guide rail effect and reduce the axial force on bolts. However, this factor is not considered by the existing analysis models. Shear tests of bolted joints under different normal stresses were carried out in the laboratory. During the test, the axial force on each point monitored on the bolt was recorded by a strain gauge, and the attenuation trend of the strain was studied. An analytical model that considers the inhibition of the bolt rail effect due to an increase in the normal stress was proposed to predict the shear mechanical behaviour of rock bolted joints. The new model accommodates the bolt shear behaviours in the elastic stage and plastic stage, and the estimated values agree well with the results of the direct shear tests in the laboratory. The validation shows that the proposed model can effectively describe the deformation characteristics of the bolts in the shear tests.

岩石螺栓已被广泛用于斜坡作为加固措施。由于影响螺栓上的轴向力和剪切力的复杂因素，对螺栓连接的节理的剪切力学行为进行建模非常复杂。剪力作用下的锚杆具有导轨作用。也就是说，岩体沿着锚杆滑动，就像锚杆是轨道一样。法向应力会抑制导轨的作用并减小螺栓的轴向力。但是，现有分析模型未考虑此因素。在实验室中进行了不同法向应力下螺栓连接的剪切试验。在测试过程中，通过应变仪记录在螺栓上监控的每个点上的轴向力，并研究了应变的衰减趋势。提出了一种分析模型，该模型考虑了由于法向应力的增加而对螺栓轨道效应产生的抑制作用，以预测岩石螺栓接头的剪切力学行为。新模型适应了弹性阶段和塑性阶段的螺栓剪切行为，并且估计值与实验室中的直接剪切测试的结果非常吻合。验证表明，所提出的模型可以有效地描述螺栓在剪切试​​验中的变形特性。