Vergleichsrechnungen zu Modellierungsvarianten für Tunnel mit Tübbingauskleidung

Comparative Analyses of Modeling Alternatives of Tunnels with Concrete Lining Segments

Task-oriented alternative modelling techniques are popular in mechanised tunnelling to calculate internal forces and deformations, to analyse stresses or to design. For detailing and designing lining segments beams on elastic foundation are often favoured. Those models idealise the soil-structure interaction employing compression-only springs and approximate the circular tunnel shell by polygonal beam members. By contrast and to account for a holistic three-dimensional impact of the tunnel on the soil more sophisticated continuum models, utilising nonlinear constitutive laws, are preferred. Here, the circular tunnel shell interacts in compression with the surrounding soil by contact and friction. Apart from the final state scenario associated with an immediately activated tunnel lining, intermediate construction stages due to sequential driving along with a stepwise consecutive installation of lining segments and specific loading scenarios from grouting or back pressure can explicitly be accounted for. Complementary to nonlinear numerical simulation well-known analytical results provide a sound fundamental basis for control. The contribution contrasts and assesses alternative modelling approaches regarding features, demands and adequacy. For the last one, numerical results are analysed in variation of decisive soil properties with respect to radial deformations in relevant load combinations.