盾构隧道变阻滑移锚式接头抗剪性能研究

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

摘要:

盾构隧道管片接头是整体衬砌结构的薄弱环节，接缝张开量超限极易导致结构出现不同程度的损伤和破坏。针对盾构隧道环间大变形问题，提出了一种变阻滑移锚式接头，并基于有限元软件ABAQUS，建立了接头?管片三维精细化数值模型，考虑管片厚度、强度、轴力等影响因素对接头?管片结构抗剪性能及破坏机理展开深入研究。结果表明：管片强度对接头?管片结构抗剪刚度及结构损伤影响较小；不同轴力下管片损伤及套杆应力分布情况不一致，随着轴力的逐渐增加，摩擦力增大后会分担一部分剪力，造成管片损伤相应减小，而套杆损伤程度相对增加；管片较薄时难以充分发挥接头力学性能，甚至会在管片内侧表面出现裂缝进而影响衬砌结构安全。该研究成果可为新型接头的设计与加工提供技术参考。

关键词:盾构隧道;抗大变形;锚式接头;抗剪性能;数值分析

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