Subproject B2

Damage Analyses and Concepts for Damage-Tolerant Tunnel Linings


The goal of the subproject B2 is to develop a numerical simulation platform for tunnel linings in order to generate new, robust lining designs. This is accomplished by combining numerical models at the material, segment, and lining system scales into a holistic simulation that is able to account for all the relevant physical processes that influence lining behavior. By means of such multi-scale and multi-level models, the influence of selected design variables (from the level of the individual fiber to the structural level) on several proposed heterogeneous fiber reinforced concrete lining designs can be investigated. Furthermore, these methods provide a framework with which to assess a specific lining design’s sensitivity to installation and production imperfections and with which the design’s suitability for use in mechanized tunneling can be determined.

Robust design procedure splitting reinforcement at the longitudinal joint of a tunnel lining with respect to radial segment misplacement during installation for hybrid and fully steel-fiber reinforced concrete (SFRC) segment designs. a) Schematic of experimental setup for Standard SFRC linings and for partially reinforced hybrid SFRC linings. b) Crack distribution at the longitudinal joint in hybrid SFRC segments (top) and traditionally reinforced segments (bottom). c) Crack response of various segment designs with respect to increasing magnitude of misplacements.

Simulation of fiber flow during casting process of a steel fiber reinforced concrete segment. a) Schematic of concrete flowing into segment mold. b) Velocity distribution of concrete within the segment model during casting. c) Fiber orientation within the segment mold.

Effect of fiber content on steel fiber reinforced concrete (SFRC) segment response with respect to hydraulic jack loadings under missing partial support due to improper segment installation. a) Schematic of the loading scenario. b) Crack response of an unreinforced concrete segment. c) Crack response of a SFRC segment reinforced using 60 kg/m^3 high-strength Fibers