RESEARCH OF MECHANICAL MODEL OF SHIELD TUNNEL'S SEGMENT JOINT UNDER THE SHEARING EFFECT

At present, the tangential direction in widely used research model of segment joint is often regarded as rigid. These models mostly have considered the effect caused by axial force and bending moment, but ignored the effect of shear force. However, many engineering problems (shear failure, segment dislocation, etc.) may occur if the shear force is ignored. This paper takes the displacement in axial, tangential and rotating directions as known loads, and then derives the stiffness matrix of the bolt and the segment concrete separately. Then, the mechanical model of segment joint, which considers the shear force, is obtained by synthesizing all the stiffness matrix. Based on the Shizi Yang shield tunnel, the calculation results of the finite element method and the proposed model are compared. The results by finite element method and the model are in good consistency. The model is more practical by considering the coupling effect which is caused by the axial force, shear force and bending moment. This research is expected to be useful to the study of the mechanical model of segment joint.