Numerical simulation is a useful tool in investigating the loading performance of rock bolts. The cable structural elements (cableSELs) in FLAC3D are commonly adopted to simulate rock bolts to solve geotechnical issues. In this study, the bonding performance of the interface between the rock bolt and the grout material was simulated with a two-stage shearing coupling model. Furthermore, the FISH language was used to incorporate this two-stage shear coupling model into FLAC3D to modify the current cableSELs. Comparison was performed between numerical and experimental results to confirm that the numerical approach can properly simulate the loading performance of rock bolts. Based on the modified cableSELs, the influence of the bolt diameter on the performance of rock bolts and the shear stress propagation along the interface between the bolt and the grout were studied. The simulation results indicated that the load transfer capacity of rock bolts rose with the rock bolt diameter apparently. With the bolt diameter increasing, the performance of the rock bolting system was likely to change from the ductile behaviour to the brittle behaviour. Moreover, after the rock bolt was loaded, the position where the maximum shear stress occurred was variable. Specifically, with the continuous loading, it shifted from the rock bolt loaded end to the other end.

数值模拟是研究锚杆载荷性能的有用工具。FLAC3D中的电缆结构元件（电缆SEL）通常用于模拟锚杆，以解决岩土工程问题。在这项研究中，用两阶段剪切耦合模型模拟了锚杆与灌浆材料之间的界面的粘结性能。此外，使用FISH语言将此两阶段剪切耦合模型合并到FLAC3D中，以修改当前的cableSEL。数值与实验结果进行了比较，以确认数值方法可以正确模拟锚杆的荷载性能。根据修改后的电缆SEL，研究了锚杆直径对岩石锚杆性能的影响以及剪切应力沿锚杆与灌浆界面的传播。仿真结果表明，锚杆的承载能力随着锚杆直径的增大而明显增加。随着锚杆直径的增加，锚杆锚固系统的性能可能会从延性转变为脆性。此外，在加载了锚杆之后，发生最大剪切应力的位置是可变的。具体地说，在连续加载的情况下，它从锚杆的加载端移到了另一端。岩石锚固系统的性能可能会从延性转变为脆性。此外，在加载了锚杆之后，发生最大剪切应力的位置是可变的。具体地说，在连续加载的情况下，它从锚杆的加载端移到了另一端。岩石锚固系统的性能可能会从延性转变为脆性。此外，在加载了锚杆之后，发生最大剪切应力的位置是可变的。具体地说，在连续加载的情况下，它从锚杆的加载端移到了另一端。