# Axial Load Transfer Mechanism in Fully Grounded Rock Bolting System: A Systematic Review
## 3 Analysis and Results
### Descriptive Results
#### 3.1.5 Articles Leading Research on Axial Load Transfer Mechanism of FGRBSs  
Table 4 highlights the most frequently cited articles identified within the reviewed literature. Articles receiving more than 50 citations were considered particularly influential in investigating the axial load transfer mechanism of FGRBSs. Applying this threshold, ten key papers were selected. These highly cited articles originated from a diverse range of six journals. Notably, both \"International Journal of Rock Mechanics and Mining Sciences\" and \"Tunnelling and Underground Space Technology\" emerged as leaders, publishing four and two articles, respectively. The remaining four contributing journals, ranked by citation counts, were \"Construction and Building Materials\", \"International Journal for Numerical and Analytical Methods in Geomechanics\", \"Journal of Rock Mechanics and Geotechnical Engineering\", and \"Rock Mechanics and Rock Engineering\". As concluded from Table 4, the most highly cited articles on the axial load transfer mechanism of fully denoted rock bolts were categorised into three different methods, including (a) analytical approaches; (b) in-situ or in-laboratory pull-out tests, and (c) numerical simulation. Also, it is noteworthy that, in seven articles, pull-out tests were conducted by the researchers to verify the results of numerical simulation and analytical approaches of FGRBSs under axial load condition. However, two highly reputed articles, including those of [PERSON] et al. [38] and [PERSON] et al. [39], relied directly on pull-out test results. For this, [PERSON] et al. [38] published their articles entitled \"Effect of grout properties on the pull-out load capacity of fully grouted rock bolt\" in Tunnelling and Underground Space Technology, received 170 citations. This study suggested the various experimental relationships between key factors like bolt characteristics, grout behaviour (including curing time (CT), water-to-grout ratio (W/G), and uniaxial compressive strength (UCS)), and their impact on the maximum pull-out capacity of fully grouted rock bolt systems. [PERSON] et al. [39] also applied the pull-out test to investigate the effects of different types of rock bolts and cable bolts, embedment length (EL), confining pressure, grouting types, and different boundary conditions on debonding mechanism at B-G interface. They also provided an extensive dataset for further studying the effects of confining pressure and embedment length on performance of FGRBSs. In terms of analytical approaches, seven articles were published on the topic. The most cited article, published in the International Journal of Rock Mechanics and Mining Sciences by [PERSON] and [PERSON] [40], garnered 294 citations. This research work presented three different analytical models focusing on the mechanical coupling between the bolt and the grout medium for rock bolting systems subjected to: (a) laboratory pull-out tests; (b) in-situ uniform rock deformation; and (c) in-situ opening of a rock joint. Their research works confirmed the previous outcomes of the pick-up length, the anchorage length, and the neutral point of the in-situ bolt. They considered three different zones, including elastic, linear behaviour of axial stress along the bolt in softening, and debonding zones. They concluded that the peak shear strength of the B-G interface was higher than shear stress values in FGRBSs. However, these values were approximately the same in fully frictionally coupled rock bolting systems. The results also reveal that the face plate could enhance the performance of the rock bolting systems. They found that the opening of the jointed rock masses may induce several axial peaks along the bolt. Their interface shear stress distribution model was subsequently developed by [PERSON] et al. (2018) by taking account into the constitutive model of bolt, tensile failure of the bolt shank, complete debonding B-G interface, and loss of face plate.