Design method for longitudinal segment joints of shield tunnel model

In consideration of the similarity between the bending stiffness of longitudinal joint of an installed scale model segment ring and that of the corresponding prototype one which is difficult to be satisfied, application of grooved model joints for a scale model for shield tunnel is proposed. The design method for the grooved model joints, slotted at both sides, slotted internally and slotted externally, is obtained. By comparing the calculated results of a model segment ring with grooved model joints with those of a beam-spring model, it is verified that the design method for the grooved model joints is feasible, and that the grooved model joints can simulate the installed ones well. After the analysis of influence of slotting on the internal width force and deformation of the segment ring, it is proposed that the corresponding central angle of the grooved model joints should be 3°to 5°. The proposed design theory of the grooved model joints is applicable for the design of a longitudinal joint of the scale model segment ring and for the numerical simulation based on uniform rigidity ring with bending rigidity to be reduced locally.