Research on the Behavior and Modified Formula of the Longitudinal Deformation Curve in Surrounding Rock of Three-Dimensional Inclined Roadways

To provide theoretical support for determining the installation timing and stability analysis of support structures for surrounding rock in inclined mine circular roadways, this study takes the inclined mine circular roadway as the research object. The research reveals the influence laws of the coupling between geological structural factors and mechanical parameters on the Longitudinal Deformation Profile (LDP) curve of the inclined mine circular roadway in three-dimensional space. A modified formula for the LDP curve of the inclined mine circular roadway, incorporating the coupling of geological structural factors and mechanical parameters in three-dimensional space, is proposed. The results indicate that the geological structural factors α and β, along with the shear strength parameters of the rock mass, have a significant impact on the shape of the LDP curve. The influence range of parameter α on the LDP curve morphology is between X/R = -6 and 6. The influence range of parameters β, cohesion, and internal friction angle on the LDP curve morphology is between X/R = -6 and 9. The axial lateral pressure coefficient, horizontal lateral pressure coefficient, and elastic modulus have a relatively minor influence on the shape of the LDP curve. The influence of Poisson's ratio on the displacement release factor is mainly concentrated near the excavation face, affecting the LDP curve morphology within the range of X/R = -1 to 3. A comparison between the proposed modified fitting formula and numerical simulation results shows that this fitting formula can effectively predict the spatiotemporal distribution of surrounding rock deformation.