Abstract:

The shield segment and rubber cushion are simulated by concrete specimens with rubber cushion to study the contact characteristics of shield segment joints. The contact characteristics of the joints of shield segment are investigated by direct shear test and uniaxial compression test under cyclic loading and unloading conditions. The test results show that: 1) The shearing process can be divided into elastic deformation, elastoplastic deformation and strain softening stage; and the residual percentage of the peak shear stress is about 55%- 65%. 2) The rubber cushion plays a good buffer role between the concretes, which may delay the buckling failure of the tunnel segments. 3）The normal and tangential contact stiffness of the contact surface is obtained when the concrete strength of the tunnel segments is C50 and the thickness of the cushion is 2 mm, so as to provide reference for analyzing and calculating the contact friction of the cushion.

Key words: shield segment, joints, contact friction, rubber cushion, contact stiffness