复杂接缝面管片接头的力学性能数值分析

Numerical Analysis of Mechanical Property of Shield Tunnel Segmental Joint with Complex Interface

根据武汉长江隧道工程管片接头所具有的复杂接缝结构特点,采用三维非线性有限元方法,对管片混凝土和接头承压衬垫均采用非线性材料性质,对螺栓采用三维实体结构模拟并考虑了螺栓预紧力的作用,对榫头采用三维实体模拟并考虑了接触关系,完成了对管片接头力学特征的分析研究。分析表明,接头弯曲刚度随接头弯矩增大而明显减小,但当弯矩增至一定程度后,接头切线弯曲刚度反有轻微增大;随接头弯矩的增长,端面混凝土最大压应力也相应增大,但当接头弯矩增到一定程度后,接头端面混凝土最大压应力数值趋于稳定不变;随接头正弯矩增大,弯螺栓拉应力将有明显提高,而随接头负弯矩增大,弯螺栓拉应力将会有所衰减。研究结论可供类似盾构隧道工程参考。

According to the characteristics of complex interface of the segmental joint in Wuhan Yangtze river tunnel the mechanical property of segmental joint is investigated. A nonlinear threedimensional finite element model of segmental joint has been established. This calculation model considered nonlinear characteristic of concrete and pressed gasket material, and simulated bolt pretension forces and interface contact. Then, the analysis on mechani cal characteristic of segment joint has been performed. The study shows that, segmental joint bending stiffness is de creased obviously with increase of the bending moment, but when the bending moment rises to a certain extent, the segment joint tangent bending stiffness increases slightly. With the joint bending moment rising, the maximum pres sure of segment joint concrete increases correspondingly; when the bending moment is large enough, the maximum pressure value tends to be stable. The bolt tension stress will be markedly improved with joint positive moment in creasing, but with joint negative moment increasing, the bolt tension stress will decrease. The study can be taken as reference for similar shield tunnel projects.