Study of Grouting Reinforcement Mechanism in Fractured Rock Mass and Its Engineering Application

Abstract

Grouting reinforcement technology is a vital component of geotechnical engineering, which plays a crucial role in repairing surrounding rock that is damaged and improving its strength. To analyze the impact of grouting on the mechanical properties of rock fractures, specimens of mudstone fractures were selected before and after grouting reinforcement for direct shear tests. The purpose was to investigate the changes in mechanical properties under normal and tangential loading conditions. Furthermore, the microscopic–mesoscopic and macroscopic aspects of grouting reinforcement were discussed to explore its influence on the interface structure, deformation resistance, and strength of the fractured rock mass. By analyzing the test results of the fracture’s mechanical properties before and after grouting, a constitutive model and strength criterion were proposed to accurately describe the mechanical behavior of the fracture surface. Building on a numerical software platform, the custom model was compiled with the VC++ integral programming environment and embedded in UDEC software. Finally, these findings were successfully applied to a typical deep roadway surrounding rock grouting reinforcement project, which showcased the practical implications of this paper. The results demonstrate that grouting reinforcement significantly impacts the normal and tangential mechanical properties of the fracture surface and the shrinkage and dilatation mechanical behaviors. The grout filling and cementation process enhances the rock mass fracture’s resistance to deformation, effectively preventing the gradual weakening and slip in the fracture field. This improves the overall integrity and stability of the rock mass. The proposed mechanical model effectively captures the compression, shear, shrinkage, and dilatation mechanical behaviors before and after grouting. Similarly, the custom fracture grouting mechanical model could be a useful tool to simulate the behavior of grouting reinforcement in engineering rock masses.