Modeling of Early-Age Creep of Shotcrete. II: Application to Tunneling

Abstract

This paper presents the application of the material model presented in the companion paper to the structural analysis of tunnels driven according to the new Austrian tunneling method (NATM). On the one hand, two-dimensional simulations of the excavation of a tunnel driven according to the NATM are presented. They show the significance of shotcrete creep for the soil-shotcrete compound structure. These simulations constitute the main part of the paper. On the other hand, as an outlook, a hybrid method is addressed that combines, (in the framework of nonlinear finite-element analyses) the aforementioned material law with three-dimensional in situ displacement measurements performed continuously during the construction process of NATM tunnels. This method enables continuous safety assessment of tunnels and, hence, contributes essentially to online monitoring of tunnels.