Abstract
The paper presents 2D and 3D analyses of an exploratory adit and 3D analyses of a NATM tunnel in stiff clays using two constitutive models (hypoplastic model for clays and Mohr-Coulomb model). The convergence-confinement method CCM with stress-release parameter λ was used in 2D simulations of the adit.
To ensure that the 2D and 3D analyses give the same displacement field the parameter λ had been optimised. The constitutive model parameters were subsequently optimised using monitoring data from the adit.
Parameters of the hypoplastic model did not change substantially. The Mohr-Coulomb model gives correct predictions only for unrealistic model parameters and low K0 values.
The 3D model of the tunnel with optimised parameters was set together and resulting simulations compared with actual monitoring data. In a case of hypoplastic model a good agreement was found.