A posteriori error estimation and adaptive mesh refinement in chemoplastic analyses of shotcrete tunnel linings

This paper deals with the development of an error estimator for complex material models considering aging elasticity, cracking, and creep. Such material models are nowadays used in the context of hybrid finite element (FE) analyses of shotcrete tunnel linings. They allow to account for the interaction between the deformations of the surrounding soil and the hydrating shotcrete, providing the level of loading of the lining during the excavation of the tunnel. The proposed error estimator is based on a stress recovery scheme. The difference between the so-obtained improved stress field and the FE results is used for the determination of error measures related to the elastic, plastic, and viscous material response. The performance of the proposed error estimator in the context of adaptive mesh refinement is illustrated by a hybrid analysis of the Semmering pilot tunnel, recently constructed in Austria. First results obtained from uniform and adaptive mesh refinement are presented.