## 1 Introduction  
Rock masses in nature are subjected to prolonged and complex geological tectonic stresses, leading to the formation of discontinuous structural planes such as cracks, joints, and faults [1]. In seasonal frozen regions, long-term freeze-thaw cycles induce water-ice phase transitions within these macro- and micro-defects, generating frost heave forces that promote the expansion of pre-existing defects and the formation of new cracks. Over time, this process leads to the interconnection of joints and cracks, ultimately causing fracture failure, which directly compromises the stability of rock mass engineering and contributes to widespread frost damage [2, 3, 4]. Numerous engineering practices have demonstrated that the grouted reinforcement of fractured rock masses is one of the most effective and practical solutions for addressing these issues [5, 6]. Grouting allows the slurry to permeate and fill fractures within the rock mass, which then solidifies, cementing the cracks and creating an integrated reinforcement. This process enhances the structural integrity of fractured rock masses, significantly improving their physical and mechanical properties [7]. However, prolonged exposure to freeze-thaw cycles in seasonally frozen regions severely compromises the internal structure and mechanical properties of grouted reinforcement bodies, posing substantial risks to the stability and safety of rock mass engineering. Therefore, to mitigate freeze-thaw hazards affecting grouting projects in seasonal frozen regions and to ensure the safety of engineering structures, it is essential to investigate the physical and mechanical properties of fractured rock grouting reinforcement bodies under the influence of freeze-thaw cycles. Current research on the physical and mechanical properties of grouted reinforcement bodies in fractured rock primarily focuses on the reinforcement effects of grouting on fractured rocks and the factors influencing the mechanical performance of grouting reinforcement body. Studies on the mechanical properties of fractured rock masses before and after grouting predominantly employ shear tests, uniaxial compression tests, and triaxial compression tests. A series of shear tests on the mechanical properties of fractured rock masses before and after grouting revealed that grouting significantly enhanced the shear mechanical properties, including peak strength, residual strength, and stiffness, demonstrating the effectiveness of grouting in improving the mechanical performance of fractured rock masses [8; 9; 10; 11; 12; 13; 14]. Uniaxial and triaxial compression tests on grouted fractured rock samples indicated that grouting and confining pressure markedly altered the stress-strain relationship of the rock samples, improving the post-peak ductility and deformation characteristics of the fractured rock masses [15; 16]. These studies highlight the role of grouting in enhancing the deformation characteristics of rock masses, especially under complex stress conditions. Research on the factors influencing the mechanical properties of grouting reinforcement body has primarily centered on grouting materials and fracture geometry. Drop hammer tests and uniaxial compression tests on grouted bodies with different grouting materials demonstrated that the choice of grouting material significantly influenced grouting effectiveness, with epoxy resins exhibiting superior reinforcement performance compared to cement-based materials [17; 18]. [PERSON] and [PERSON] et al. further elucidated that the strength of grouted bodies is negatively correlated with the viscosity of the grouting material and the particle size of the fractured rock mass [19; 20]. These studies provide critical insights for the selection of grouting materials.