Design method for shield tunnel model considering similarities of transverse and longitudinal rigidities

In view of the inconsistency of efficiencies of transverse and longitudinal rigidities of shield tunnels, it is difficult to design a shield tunnel model with similar transverse and longitudinal rigidities in model tests. According to the similarity design theories of model tests, the design method for the shield tunnel model with the transverse rigiditie and longitudinal rigidities both meeting the similarity requirements is proposed. The segment ring of the shield tunnel model is designed using a modified homogeneous ring model with the transverse rigidity meeting the similar requirements. The transverse rigidity of the segment ring is measured by using the symmetry pressure method. The method for the longitudinal rigidity of the shield tunnel model is proposed by using the bolt connection with spring between segment rings. The longitudinal rigidity is measured by using the simply supported beam method, and the theoretical method for the longitudinal rigidity of the shield tunnel model is verified. According to the similar relationship between the longitudinal rigidities of the model and prototype shield tunnels, the method for calculating the stiffness of spring installed on the circular joint connection bolt of the shield tunnel model is obtained.