Comprehensive Analysis of Rock Brittleness: Exploring the Impact of Surrounding Excavations in Hard Rocks

This research examines the relationship between excavations and tunnel responses, emphasizing the influence of geometric factors on tunnel heave. Utilizing an exponential correlation between heave and unloading ratio, the study investigates into stress changes with increasing excavation depth. Maintaining a constant axial horizontal distance proves crucial for stable tunnel responses. FLAC3D numerical modeling highlights increased stress-strength ratios near excavations, impacting the tunnel crown. Water ingress induces soil consolidation, leading to additional deformations, while adverse excavation conditions can cause leaks, dislocations, and cracks in the tunnel lining. The study also analyzes rock behavior under diverse loading and excavation conditions, revealing stress point relationships with the yield surface in principal stress space.