盾构隧道接头环向抗弯刚度反映了接缝在一定的轴力水平下抵抗弯矩作用产生变形的能力，具有典型的非线性特征，设计中对刚度取值的偏差会导致结构变形和内力出现差异。通过将管片接头弯矩一轴力-转角的三维曲面参数编制汇总到数据库文件中，实现接头非线性力学效应向整环模型输入的迭代计算方法。采用接头刚度迭代算法与传统的（修正）惯用法、多铰圆环法、梁一弹簧模型的内力与变形结果进行比较。运用大比尺相似结构模型试验对不同外荷载作用下的计算成果进行验证。最后采用迭代算法对复合地层条件下的衬砌结构进行计算分析，并利用现场实测数据进行验证。研究结果表明：接头刚度影响着衬砌的整环抗弯刚度，对于受力均匀的衬砌结构而言，采用梁一弹簧模型的计算结果与迭代计算模型相差不大，满足工程设计要求；对于上下交叠的软硬程度差异极大的复合地层而言，衬砌结构内力相差较大，采用接头刚度迭代算法的计算结果与现场实测值吻合较好，证实了该算法的可行性和合理性。%The relationships between joint bending moments, axial force and rotating angle are established by using FEM analysis. An iterative algorithm is carried out incorporating the nonlinear joint parameters. The results calculated by the iterative algorithm are compared with those from different methods widely used in shield tunnel lining design, such as the modified routine method, the multi-hinge ring method and the beam-spring method. In addition, the results from different calculation models under different external loads are validated by large-scale similitude model test. The iterative algorithm is also applied to analyzing the segment lining structure in layered strata and verified by field test data. The study shows that the weakening effect of segment joints influences the segment ring integral performance. For structures under uniform loading, the results of the iterative algorithm are comparable with the results of beam-spring model with identical appropriate joint bending stiffness. For tunnels across multi-layered strata with widely different hardness, there is a great disparity in bending moments between the top and the bottom of lining. The results calculated by the iterative algorithm agree well with measured values.
展开▼
