Excavation face stability analysis of deep and circular tunnels in soils and rock masses

The construction of tunnels has been instrumental in advancing infrastructure and improving transportation and communication systems. However, the stability of the excavation face presents a significant challenge in tunnel excavation. The excavation face, which separates the rock or soil mass from the tunnel support structure, is crucial for ensuring the safety and durability of the tunnel, particularly as tunnel depths increase. Numerical modelling plays a crucial role in assessing and predicting tunnel face stability. By simulating the complex interactions between the excavation face, surrounding rock or soil, and support systems, numerical models provide valuable insights into the behaviour and stability of the tunnel face. These models enable engineers to analyze various scenarios, evaluate the impact of different parameters, and make informed decisions regarding the design and construction of tunnels. With the ability to simulate real-world conditions, numerical modelling enhances our understanding of tunnel face stability and helps mitigate potential risks, ensuring the safe and efficient development of underground infrastructure. This thesis introduces a novel approach to tunnel excavation simulation, employing a single-time excavation simulation instead of a step-by-step method. This innovative approach reduces the time required for the simulation by one-third while ensuring accuracy. The proposed model is validated against the analytical spherical method, considering 81 different scenarios encompassing variations in rock types, tunnel radius, stress states, and lining thicknesses. The validation process confirms the reliability and effectiveness of the proposed model in capturing the behaviour of tunnel excavation under various conditions.