This study presents a novel constitutive model to characterise the mechanical behaviour of cable bolts under axial loading and subjected to different boundary conditions including constant confining pressure and constant normal stiffness. Such a model is developed based on the modified Mohr-Coulomb failure criterion as well as a newly proposed non-linear dilation formulae for the development of governing equations. The cone shaped failure mode of grout due to the axial movement of cable bolt is considered as a widely observable failure mode at the cable bolt to the grout interface. The load carrying capacity of the cable bolt under axial loading is significantly affected by both the progressive reduction in the volume of failed cone zone of grout annulus and the continuous degradation of dilation angle at the cable bolt to the grout interface. Hence, the full load-displacement performance of different cable bolts under axial loading subjected to both constant confining pressure and constant normal stiffness are simulated. Finally, an acceptable agreement between the model simulations and the experimental data confirms the credibility of proposed constitutive model for predicting the mechanical behaviour of different cable bolts under axial loading.

本研究提出了一种新的本构模型，用于表征在轴向载荷和不同边界条件（包括恒定围压和恒定法向刚度）下锚索的力学行为。这种模型是基于改进的 Mohr-Coulomb 失效准则以及新提出的用于开发控制方程的非线性膨胀公式而开发的。由于锚杆轴向移动而导致的灌浆锥形破坏模式被认为是锚杆到灌浆界面处广泛观察到的破坏模式。锚杆在轴向载荷下的承载能力受灌浆环失效锥区体积的逐渐减小和锚杆到灌浆界面的膨胀角的持续退化的显着影响。因此，模拟了在恒定围压和恒定法向刚度的轴向载荷下不同锚杆的全载荷位移性能。最后，模型模拟和实验数据之间的可接受的一致性证实了所提出的用于预测轴向载荷下不同锚杆机械性能的本构模型的可信度。