A constitutive model for load-displacement performance of modified cable bolts

Cable bolts are extensively used in mining and civil structures as one of the most important support systems for ground control. In order to design an effective support system, understanding the performance of cable bolts under the conditions other than those tested in the laboratory is essential. Thus, this paper outlines the development of a constitutive model that can predict the full load-displacement performance of the modified cable bolts at different confining pressures. The model includes the nonlinear dilation equation and the peak axial load envelope as the governing laws. The governing equations for the failure mechanisms at the cable to grout interface and grout annulus are coupled using advanced partial differential equations. The full load-displacement behaviour of modified cable bolts with a smooth transition from initial elastic behaviour to progressive failure is simulated using continuous yielding method. The model is then calibrated against the experimental data reported in the literature. It has been demonstrated that there is a good agreement between the model simulations and the experimental results confirming the suitability of the proposed constitutive model for performance prediction of the modified cable bolts at different confining pressures.