Investigating the relationship between erosion-induced structural damage and lining displacement parameters in shield tunnelling

Abstract

This study investigated the relationship between erosion-induced structural damage and lining displacement parameters for shield tunnelling using a finite element approach, which properly simulated the interaction between the eroded soil and tunnel structure as well as the details of the segmental liners. The interaction between the bolt rod and reserved bolt hole was simulated by a surface-surface contact. The lining concrete and bolt materials were simulated by plastic constitutive models. The internal erosion process was qualitatively modelled by a strength-and-stiffness reduction method with a progressive flow boundary on the tunnel surface. The structural damage mechanism and its relationship with the lining displacement parameters were then clarified by conducting a series of parametric studies. It was found that the damage to the lining concrete and the number of yielded circumferential bolts could be properly related to the maximum and average vertical convergence rates of the liners, respectively, while the maximum internal force of the longitudinal bolts could be identified by the axial deflection angle of adjacent liners.