Abstract: To investigate the bending behavior and damage characteristics of longitudinal segment joints in superlarge diameter shield tunnels, this study develops a three-dimensional refined numerical model based on the concrete damage plasticity (CDP) constitutive model, using the Jinan Yellow River Tunnel as a case study. Key findings include: (1) The bending behavior and damage characteristics of longitudinal joint under the bending moment exhibited obvious nonlinearity and stages. Owing to the asymmetric waterproofing structures, the deformation and failure process of segments comprised four distinct phases under positive bending moment compared to three phases under negative bending moment. (2) Pre-yield bolt stress shows non-uniform distribution, peaking at sleeve ends. There are obvious differences in the magnitude and distribution pattern of stress in the inner and outer regions of the segments. Bolt yielding under negative bending moment is delayed by 31.14% compared to positive bending moment.(3) Concrete damage propagates at 45° from the joint surface. The damage phenomenon of concrete on the surface of the sleeve side and the hand hole side was basically the same, but the damage phenomenon of concrete on the sleeve side was more serious at the bolt area, while the concrete on the hand hole side was damaged at the hand hole area.(4) Under positive moment, outer main rebars and joint-surface reinforcement experience peak stresses coinciding with concrete failure zones. The outer main rebars yield after the concrete in the compression zone was seriously damaged.