Investigation of nonlinear characteristics of segmental joints flexural performance under the influence of groove arrangement on the joint surface

Abstract

The latest shield tunnel lining design of China uses a double-groove configuration with two placement options, affecting the concrete contact area and flexural performance at the joint interface, but the specific differences in flexural performance between external and internal single-groove joints (EISGJ) and external double-groove joints (EDGJ) remain unclear. To address this, full-scale tests and refined finite element models were conducted. Following the validation of the numerical model's accuracy, parameter analyses based on groove position and groove height were performed on the joints. The results indicate that EDGJ are more sensitive to different groove arrangements under positive bending than under negative bending, while EISGJ are slightly more sensitive under positive bending. Furthermore, the flexural performance of joints after randomly sampling 100 combinations of groove position and groove height indicate that groove position has relatively great impact on the flexural performance of the EDGJ, while groove height has a stronger effect on EISGJ. This study highlights the importance of considering groove design in ensuring the joint's load-bearing performance under positive bending conditions.