Fully grouted rock bolts under axial and shear loading conditions: a systematic review

Abstract

Fully grouted rock bolts are widely used for ground control in underground excavations and slopes. Their behaviour under axial and shear loading is governed by bond-slip at the interfaces, confinement, embedment length, annulus thickness and bolt profile, which together control peak capacity and post-peak load transfer. Although many studies have examined individual aspects of this behaviour, a consolidated assessment of axial and shear load-transfer mechanisms remains limited. This review addresses that gap by systematically reviewing Scopus-indexed literature from 1988 to 2025. An initial broad search returned 977 records on rock-bolting systems. After applying focused search terms, exclusions and manual screening, 122 articles were selected for detailed bibliometric and content-based analysis. VOSviewer keyword mapping identified three main research clusters: (a) grout, pull-out testing,analytical modelling, shear stress, and shear strength; (b) finite-difference modelling and failure mechanisms; and (c) numerical simulation using the finite element method. The review also compares publication trends, leading contributors and the main technical themes shaping the field. . The findings revealed that the axial behaviour is mainly bond-controlled, whereas joint conditions, boundary constraints, and local bending more strongly influence shear behaviour. These differences highlighted the need for careful interpretation of test data and for modelling approaches that distinguished between the axial and shear load transfer mechanisms in fully grouted rock bolts.