Numerical analysis of size effect on the deformation behavior and damage evolution mechanism of segmental tunnel lining rings

This article investigates the size effect of segmental tunnel linings on the deformation behavior and the damage evolution mechanism using the Finite Element Method (FEM). A series of models with different diameters are established under the same loading condition to control the variable. The bolts and the rebar apply the elastic-plastic model. The Concrete Damage Plasticity model has been considered for the concrete lining. The vertical convergence deformation, internal force of these models, and damage to the segment body are selected for comparison. The number and location of the yielded bolts are explored for the analysis of the overall structure stiffness and damage evolution mechanism. In terms of plastic hinge theory, an extended discussion is carried out to explain the differences in damage evolution mechanisms in different-sized linings. The results show the large-diameter lining rings have a relatively greater increasing rate of convergence deformation. Furthermore, fewer plastic hinges emerged in large-scale lining rings before the structures reached their ultimate strength. According to the experimental results, we can know that the failure of large-diameter has the characteristic of more brittle damage than that of small-diameter one and these large-size structures are prone to become unstable geometry.