Analytical Modelling of Load–Displacement Performance of Cable Bolts Incorporating Cracking Propagation

Abstract

The application of cable bolts tends to increase in both underground mining operations and civil tunnel excavations have given its outstanding performance to support the excavation surface and hence minimise the hazards and risk of failure in the field. Understanding the mechanical behaviour of cable bolts under axial loading subjected to different field environment from analytical perspective is essential and economic for selecting the most appropriate cable bolt for a specific scenario and also the ground support system design. This study develops a novel analytical model coupling the crack propagation in the grout annulus to capture the load–displacement performance of cable bolts under axial loading. The majority of the input parameters associated with mechanic properties of the cable bolt and grout are readily determinable by laboratory tests. Additionally, the model simulates the ongoing varying conditions of the confinement to the grouted cable bolt during the pull-out test based on the proposed crack propagation equation, leading to a more realistic reflection of the field conditions. Finally, the capability of the proposed model to simulate the performance of cable bolts under axial loading is demonstrated by validating against experimental results in the literature.