Research on Shear Performance of Non-Constant Resistance and Slip Anchor Joint of Shield Tunnels

Abstract:

The segment joint of shield tunnel is the weak link of the whole lining structure. The joint opening displacement exceeding limit can easily lead to different degrees of damage and destruction to the structure. Aimed at the problem of large deformation between shield tunnel rings， a non-constant resistance and slip anchor joint is proposed in this paper. Based on the finite element software ABAQUS， a three-dimensional refined numerical model of joint-segment is established. Considering the influence factors such as segment thickness， segment strength and segment axial force， the shear performance and failure mechanism of joint-segment structure are studied in depth. The results show that the segment strength has little effect on the shear stiffness and structural damage of the joint-segment structure. At different axial forces， the segment damage and the stress distribution of the sleeve rod are inconsistent. With the gradual increase of the axial force， the friction force also increases and shares part of the shear force， resulting in a corresponding decrease in the damage of the segment， while the damage degree of the sleeve rod is relatively increased. When the segment is thin， it is difficult to give full play to the mechanical properties of the joint， and even cracks， appear on the inner surface of the segment， which will affect the safety of the lining structure. The research results of this paper can provide technical reference for the design and processing of new joints.

Key words:shield tunnel;large-deformation resistance;anchor joint;shear performance;numerical analysis