In this paper, the deformation characteristics of tunnel lining structures in different soils are studied by theoretical analysis, numerical modelling and field monitoring. The deformation of segmental lining was monitored by distributed optical fiber sensors in the tunnels of Foshan Metro Line 2 during EPB shield tunnelling. The structural deformation characteristics, including the longitudinal strain and curvature, the circumferential and longitudinal joint deformation, the longitudinal settlement, and the circumferential convergence of the tunnel under different ground conditions and at different depths are analysed based on the monitoring data. The optimized conjugate beam method is developed to analyse the lining deformation and the ground settlement. The PLAXIS 3D finite element model is utilized to study the effects of soil properties (cohesion and friction angle), tunnel depth and soil reinforcement on the tunnel lining deformation and ground settlement. Numerical modelling is further applied to simulate and predict the lining deformation of Foshan Metro Line 2 tunnels, which are compared with the monitoring data. The prediction results can effectively help to reduce the risks of large deformation and settlement in weak and soft grounds.

本文通过理论分析，数值模拟和现场监测研究了不同土壤中隧道衬砌结构的变形特征。在EPB盾构隧道施工中，利用分布式光纤传感器监测佛山地铁2号线隧道的分段衬砌变形。根据监测数据，分析了隧道在不同地面条件和不同深度下的结构变形特性，包括纵向应变和曲率，周向和纵向接头变形，纵向沉降和周向收敛性。提出了优化的共轭梁法来分析衬砌变形和地基沉降。利用PLAXIS 3D有限元模型来研究土壤特性（内聚力和摩擦角），隧道深度和土层加固对隧道衬砌变形和地面沉降的影响。进一步利用数值模拟方法对佛山地铁2号线隧道的衬砌变形进行了模拟和预测，并与监测数据进行了比较。预测结果可以有效地减少软弱地基中大变形和沉降的风险。