Abstract: The traditional segment joint of shield tunnels has several drawbacks, such as low assembly efficiency and poor bending performance. To address these issues, a structural design and bending performance analysis of a novel G joint is conducted. First, a novel fast assembling G joint design is proposed by combining the part design method with the traditional C-T joint structure. Based on this design proposal, a G joint is developed, and its mechanical characteristics are analyzed under actual working conditions. Following this, the structural design of the G joint is further optimized, focusing on its tensile properties. This process led to the creation of a fast-splicing head satisfying the requirements for fast splicing and strong mechanical performance. Finally, three segment joint models are established, considering their structural and material attributes. The bending stiffness of the inclined bolt joint, C-T joint, and the G joint is analyzed based on real-world conditions. Their deformation and bending moment angles are compared. The results reveal that the bending stiffness of the novel G joint is 289% higher than that of the inclined bolt joint and 161% higher than the C-T joint.

Key words: shield tunnel, novel fast assembling joint, bending stiffness, structural design