Research on the Stress Distribution Law of Fully Anchored Bolt and Analysis of Influencing Factors under the Condition of Surrounding Rock Deformation

As the mining depth increases, the deformation of the roadway becomes more difficult to control. As a main supporting structure for maintaining the stability of roadway, the fully anchored bolt is widely used to reinforce deep mine. At the same time, the analysis of the stress distribution law of fully anchored bolt is the basic work to optimize anchor design. Therefore, this paper establishes a fully anchored bolt-surrounding rock interaction model based on the law of surrounding rock deformation and derives the analytical expressions for the axial force and shear stress of the fully anchored bolt during normal support and critical failure. At the same time, the effects of surrounding rock properties, support resistance, and bolt length on the stress distribution of fully anchored bolt are analyzed. The results show that the stress distribution of fully anchored bolt is consistent with the "neutral point" theory and the most important is the fact that the conditions of surrounding rock, the supporting resistance, and the length of bolt affect the actual stress distribution of the fully anchored bolt. It provides a certain theoretical basis for the design and development of anchoring and supporting technology.