Application of a constitutive model for concrete to the analysis of a precast segmental tunnel lining

A constitutive model for concrete, based on the smeared crack approach and formulated within the framework of the theory of plasticity, is extended by coupling damage due to tensile stresses with damage due to compressive stresses for mixed tension-compression loading and by introducing an isotropic scalar damage model for unloading and reloading. Additionally, a uniaxial model for tension stiffening is extended to reinforced concrete subjected to biaxial stress states. The constitutive model for plain and reinforced concrete is validated by means of test data taken from the literature and by laboratory tests on L-shaped panels. Finally, the validated material model is used to perform a non-linear FE-analysis of a permanent tunnel lining made of hexagonal precast concrete segments. During the construction work of the lining hairline cracks were detected on the inner surface of some precast segments, running parallel to the longitudinal axis of the tunnel lining. They were supposed to be mainly caused by the installation process of the lining. In order to gain more information about the origin of these cracks, a non-linear numerical analysis of the installation process of the lining is performed. The results of the numerical simulation, showing under which conditions cracks are initiated, are presented and discussed. Copyright (C) 2004 John Wiley Sons, Ltd.