Laboratory Testing and Modeling of a High-Displacement Cable Bolt

Abstract

An energy-absorbing cable designated as constant resistance large deformation (CRLD) has been recently developed and applied to slopes and underground excavations. Under a static pull loading, the CRLD cable can exhibit a large deformation and a constant resistance with a significant radial expansion. The cable mainly consists of a cone, steel strands, and a thick-walled pipe, which is different from the thin-walled expanding oil-well cases. To analyze the strength-deformation mechanism, a laboratory static pull test was developed. The radial deformation of the cable and the evolution of the drawing force were obtained. An analytical model for the thick-walled cylinder was developed and applied to analyze the mechanical behavior of the CRLD cable in an elastic–plastic framework. The analytical model was verified by experimental results, and consequently, a sensitivity analysis was carried out. The relationship between the constant resistance and the geometrical and mechanical parameters was then revealed. Furthermore, a numerical simulation was established, and the corresponding parameters were calibrated in line with the experimental results. The numerical results were compared with the experimental and analytical ones, and excellent agreement was found. An additional sensitivity study was conducted in relation to the metal yield limit. Both models proved to be reliable as assistive tools to design and improve CRLD cables in the future.