# Axial Load Transfer Mechanism in Fully Grounded Rock Bolting System: A Systematic Review
## 1 Introduction
Their CMC design provides a much higher axial stiffness--10 to 20 times greater than pointed anchor bolts with wedges or expansion shells. Additionally, their larger cross-section translates into superior performance against frictional bolts like Swellex [16; 18]. Figure 1: FGRBS types: (**top**) fully resin-grouted rock bolts; (**bottom**) fully cement-grouted rock bolts [17]. Along with the interaction between internal fixtures and with rock and bolt, it is noteworthy to mention that another key factor in the classification of rock bolting systems is the length of embedment length (EL), which comes in full columns or in sections. Full-column bolts provide maximum support by anchoring along their entire length. However, in the case of segmental embedding, the bolt rod is subject to greater deformation, which is sometimes a desirable feature, especially for a rock mass in which tremors occur [19; 20; 21]. FGRB performance under external loads is influenced by two key factors: the mode of the applied force and the in-situ bolt arrangement [22]. The bolt response to the subjected loads may be predominantly shear, axial (tension) or flexural; however, the typical behaviour is indeed a combination of all of them [6; 23]. In this article, the pure axial behaviour of rock bolts will be investigated in detail and other aspects are out of this study's scope. Dilation of a discontinuity creates an axial load inside the bolt which can then be transferred laterally to the grout. This load transformation causes interfacial shear stress at the bolt-grout (B-G) and rock-grout (R-G) interfaces. The FGRBSs can fail under the axial loading mechanism in one of the five following ways: failing the bolt element, grout, the surrounding rocks, the B-G interface, or the surrounding rocks and grout [24]. The critical role of load behaviour in rock bolt performance has driven extensive research efforts for several decades, employing experimental, analytical, and numerical simulation techniques. However, there are limited identified research studies conducted on investigating axial load behaviour mechanisms in FGRBSs. Although individual research efforts play a crucial role in advancing knowledge, a comprehensive perspective that integrates these diverse findings is often lacking. Such a perspective would be essential for establishing a more holistic understanding of investigating axial load behaviour on the performance of a FGRBS. Therefore, a critical need exists for a systematic review to consolidate and analyse the findings from various sources relevant to the investigation of axial load mechanism on FGRBSs. A Systematic review provides a robust and transparent methodology for comprehensively identifying, selecting, and evaluating relevant research on a specific topic. By synthesising existing knowledge through an unbiased and comprehensive analysis, a systematic review can inform future research and practical applications, while also highlighting areas where further investigation is necessary [25; 26]. The vast amount of research on FGRBSs necessitates the use of science mapping within the systematic review process. This approach provides a powerful tool to navigate this complex field and identify key research areas. Given the lack of a comprehensive understanding of past research and future needs, this study aims to synthesise relevant research and explore the investigation of the axial load transfer mechanism of FGRBSs. This review article uses bibliometric analysis techniques to show research collaboration networks and research clusters within FGRBSs. The review examines 77 peer-reviewed journal articles published between 1988 and 2024. The main objectives of this systematic review are as follows: (a) summarising the current state of research in axial load transfer mechanism of FGRBSs; (b) identifying key researchers, collaboration networks, and preferred publication outlets; (c) uncovering emerging research trends through cluster analysis and pinpoint knowledge gaps, and (d) proposing potential avenues for future research directions.