Predicting the Shear Resistance Contribution of Passive Fully Grouted Bolts to Jointed Rock

Abstract

Based on the statically indeterminate beam model for fully grouted bolts proposed by others and taking into account the combination of the axial and shear forces activated in the bolt, an improved method was developed for predicting the shear resistance contribution of passive fully grouted bolts to jointed rock. An algorithm for calculating the length of the transverse deformation section of a passive fully grouted bolt under shearing was derived by incorporating the minimum total potential energy principle, and parametric investigations were carried out to evaluate the effect of the anchoring parameters, such as bolt diameter, rock strength, bolting angle, and joint friction angle on the bolt contribution. Comparisons were made between the developed method and laboratory shear test results as well as between the developed method and other analytical predictions proposed by previous studies. The results showed that the theoretical model presented in this paper is in good agreement with the experimental results and, thus, provides a better prediction of the shear resistance provided by rock bolts. The presented analytical method can be used to improve the bolting design for the reinforcement of jointed rock.