考虑接触非线性的盾构隧道纵向分析模型及其应用

Longitudinal Analysis Model of Shield Tunnel Considering Contact Nonlinearity and Its Application

盾构隧道环缝接触状态与传递的内力有关,但传统盾构隧道结构分析模型不能考虑轴力、剪力、弯矩共同作用下的环缝接触非线性。提出了一种考虑3种内力共同作用下接触非线性的盾构隧道纵向分析模型,并据此对汕头湾盾构隧道穿越蠕滑断层的力学行为进行分析。研究发现:(1)当考虑纵向接头同时传递轴力、剪力、弯矩时,其传力作用可等效为考虑轴向和弯曲刚度折减的梁,其折减系数与位移偏心距有关;(2)汕头湾盾构隧道在蠕滑作用下的力学分析表明,纵向接头接触非线性对结构内力影响较大,忽视非线性的影响可能带来1.4~3.3倍的误差。研究成果可用于蠕滑断层位错等复杂荷载作用下的盾构隧道纵向力学行为分析。

The contact state between the shield tunnel rings is related to the internal force.The traditional shield tunnel structure analysis model cannot consider the contact nonlinearity under the combined action of axial force,shear force,and bending moment.Therefore,this paper proposes a shield tunnel longitudinal analysis model considering the nonlinear contact under the combined action of axial force,shear force,and bending moment.This analysis method is used to analyze the mechanical behavior of the shield tunnel crossing a creeping fault in Shantou Bay.It is found that when the longitudinal joint transmits axial force,shear force,and bending moment at the same time,its force transmission effect can be equivalent to the beam considering the reduction of axial and bending stiffness,and its reduction coefficient is related to the displacement eccentricity.The mechanical analysis of the shield tunnel under creeping load shows that the contact nonlinear longitudinal joint has a great influence on the internal force of the structure,and ignoring the influence of nonlinearity may cause more than 1.4 to 3.3 times of internal force difference.The research results in this paper can be used to analyze the longitudinal mechanical behavior of shield tunnels under complex loads such as creeping fault dislocation.