Abstract: The numerical results of segmental joint of shield tunnel often cannot accurately reflect the actual force and deformation process of the joints. Hence, a threedimensional refined numerical model of segmental joint of Sutong GIL project is established, in which solid elements are used to simulate the concrete, bolts, sleeve, gaskets, etc.[KG-*3], beam elements are used to simulate the reinforcements, and preload are applied on the bolt. Based on the numerical model, the calculation is carried out and compared with the fullscale compressionbending test to verify its accuracy.  The numerical model is used to analyze the influence of bolt connection state on the bending performance of the joint. The results show that: (1) The threedimensional refined model of the joint can reflect the deformation law under compressive bending loads, and it has good calculation accuracy. (2) Under positive and negative bending moments, the joint is prone to opening and vertical deformation when there is no bolt; the joints with/without bolt has a greater impact on the joint opening and vertical deformation, and the influences are related to the magnitude of axial force and bending moment under positive bending, while the difference between influence of joint with bolt and that of joint without bolt is small and basically unchanged under negative bending. (3) When the joint is connected by oblique bolts, the influence of the joint with/without bolt on the bending stiffness of the joint under positive bending is greater than that under negative bending.

Key words: shield tunnel, segmental joint, threedimensional refined model, bending performance, fullscale joint test, boltless