To understand the longitudinal structural deformation mechanism of shield tunnel linings, it is crucial to reasonably consider circumferential joints, especially their shearing deformation. Towards that end, first, the dislocation between lining rings caused by the differential settlement of an actual tunnel project in Shanghai was introduced in detail. Next, the longitudinal deformation model of shield tunnels derived from Timoshenko beam theory was revised to predict the actual deformation more accurately. Then, a homogeneous solid ring-spring numerical model considering a novel treatment for the circumferential joint was proposed and validated with the aid of field data. Furthermore, to enhance the understanding of the longitudinal deformation mechanism caused by differential settlement, the longitudinal deformation of the selected project and additional cases was analysed in detail by using the proposed model. The results show that the longitudinal deformation caused by differential settlement comprises both dislocations (shearing deformation) and openings (bending deformation) between lining rings, although the dislocation deformation is observed to be more significant for the selected case. When the distance is close to the special lining rings (the maximum of the differential settlement), the dislocation increases first and then decreases. There is an abrupt increase between lining rings for the shear stress, which is the main reason for the dislocation of the circumferential joints. The opening of the circumferential joint that occurs at the invert of the shield tunnel next to both sides of the special lining rings is found to be severe and potentially hazardous.

理解盾构隧道衬砌纵向结构变形机理，合理考虑周向节理，尤其是其剪切变形至关重要。为此，首先详细介绍了上海某实际隧道工程因不均匀沉降引起的衬砌环间错位。其次，对铁木辛柯梁理论衍生的盾构隧道纵向变形模型进行了修正，以更准确地预测实际变形。然后，在现场数据的帮助下，提出并验证了一种均匀实体环弹簧数值模型，该模型考虑了一种新的圆周接头处理方法。此外，为了加深对差异沉降引起的纵向变形机制的理解，使用建议的模型详细分析了所选项目和其他情况的纵向变形。结果表明，由不同沉降引起的纵向变形包括衬套环之间的位错（剪切变形）和开口（弯曲变形），尽管在所选情况下观察到位错变形更为显着。当距离靠近特殊衬环时（差异沉降的最大值），位错先增大后减小。衬环之间的剪应力突然增大，这是造成环缝错位的主要原因。