ABSTRACT
This study investigates the effect of time-dependent deformation on mechanically constructed tunnels, focusing on swelling activation after excavation. Sensitivity analysis evaluates key parameters such as suppression pressure, and other swelling coefficients (21 number of input parameters required to fully define this constitutive model in the finite element software used here). The Georgian Bay Formation, a Silurian-Ordovician geological formation from Ontario, Canada, known for its highly anisotropic and swelling-prone shale, serves as the case study. The swelling Rock Model in 2D Plaxis is used for this study which simulates the anisotropic swelling behavior of rock. Defining the extend of the swelling zone around the excavation area is crucial for a more realistic prediction of the swelling effects. Parameters such as suppression pressure, A0 and Swelling ID are also critical to the design of a large span cavern lining in such geological conditions.
