错缝拼装盾构隧道结构横纵向性能相关性及作用机理研究

To the characteristic and correlation problem of transverse-longitudinal force and deformation of shield-tunnel structure with staggered joint, the longitudinal distribution of joint deformation, soil resistance and transverse-longitudinal effective rigidity ratio is studied by model test. For transverse-longitudinal structure performance, the effect of bolt pre-tightening force, Concave-convex tenon, jacking force, and longitudinal segment constraint is analyzed. Under shear loads, the distribution coefficient of concave-convex tenon, ring surface, and bolts is obtained in the ring joint. The relationship function of longitudinal curvature radius, convergence deformation, ring-joint dislocation and angle is established. The relationship function of convergence deformation, longitudinal-joint dislocation and angle is established. Based on the test results, with D'Alembert's principle and force method, the relationship of convergence deformation, longitudinal-joint deformation and stress, and effect of ring-joint force on transverse deformation and stress is interpreted by an analytical method. With the principle of longitudinal equivalent rigidity, ring-joint deformation-stress characteristic and effect of transverse deformation and stress on ring-joint force is studied under shear loads. It establishes modified equivalent longitudinal rigidity model for calculating deformation and stress in the ring joint and longitudinal joint. As a theoretical basis, structural health evaluation standard is provided for operating protection and repair of metro staggered-joint shield tunnel by this project.

针对错缝拼装盾构隧道结构纵横向受力与变形特征及相关性问题。首先，通过模型试验，研究接缝变形、地基抗力、横纵向刚度有效率的纵向分布特征；研究螺栓预紧力、凹凸榫、千斤顶推力、纵向管片约束对结构纵横向性能的影响；确定纯剪状态下环缝处环面、凹凸榫和螺栓的剪力分配系数；分别建立纵向曲率半径与收敛变形、环缝处错台量及张角，收敛变形与纵缝处错台及张角的关系函数。其次，基于试验结果，利用达朗贝尔原理和力法，建立一种解析式，诠释隧道收敛变形与纵缝处变形和受力的关系，以及环缝处受力对横向受力和变形的影响；利用纵向等效刚度原理，研究剪切力作用下环缝处变形和受力特征，横向变形和受力对环缝受力的影响，建立可全面计算纵环缝处受力和变形的修正纵向等效刚度模型。最终，给出错缝拼装衬砌结构健康评判标准，为地铁盾构隧道运营防护与维修提供理论依据。

本项目以错缝拼装盾构隧道结构纵横向受力与变形特征及相关性问题为总体研究目标，利用数值模拟、现场试验、室内模型试验、统计分析及理论计算等方法，对错缝拼装盾构隧道长期沉降过程中衬砌管片产生纵向变形时横纵向力学性能相关性性进行了系统化分析。提出了运营隧道长期沉降规律及纵向错台分布特征；给出了隧道收敛变形与上浮量的关系函数；组建了双面弹性地基梁-纵向等效连续化模型，得到了整体衬砌结构在局部均布荷载作用下的弯矩和剪力以及纵向连接螺栓由于受弯引起的拉应力；建立了纵向连接螺栓的受力计算模型，并给出了环缝处结构处于不同受力状态下纵向连接螺栓的总拉应力和总剪应力；给出了当以纵向连接螺栓的受拉屈服强度作为环间界限变形量的评判标准时的环间变形量，以及在满足密封垫防水要求的极限状态下，纵向连接螺栓剪切破坏模式；提出了以纵向连接螺栓的受拉屈服强度作为环间界限变形量的评判标准时，环缝结构设计参数对环间错台量和张开量界限值的影响度。完成了9组均质管片、部分均质管片和错缝拼装管片室内模型试验，提出了考虑土体作用下错缝拼装衬砌结构横纵向刚度有效率；给出了错缝拼装衬砌管片横纵向变形和受力分布特征及演化规律；建立了衬砌结构横纵向变形和受力关系函数；考虑横纵向变形和受力相关性，修正了等效连续化刚度模型。