针对软弱地层盾构隧道管片脱出盾尾后出现的上浮问题，分析盾构施工过程中管片上浮的诱因，得出软弱地层中管片的上浮主要是地层应力重分布产生的地基回弹力引起的。在此基础上建立隧道开挖动态模型，分析隧道上浮量变化规律以及地层特性对管片上浮量的影响规律，得出地层弹性模量和管片上浮量呈一定的指数关系，且弹性模量对管片上浮量的影响远大于地层黏聚力和内摩擦角。通过力平衡理论计算盾构开挖引起的地层回弹力、管片上浮量以及隧道上浮影响的地层高度范围，并通过对珠江狮子洋工程管片上浮量的计算与实测对比，证明该公式的合理性，为盾构隧道工程中考虑地基抗力引起的管片上浮量预测提供一种新的方法。

The mechanism analysis of segment upfloating during construction is conducted. The main cause of segment upfloating in softandweak stratum is formation rebound induced by stratum stress redistribution; the variation rule of tunnel upfloating amount and the influence of stratum characteristics on segment upfloatation are analyzed by dynamic model of tunnel excavation; the elasticity modulus and the amount of segment upfloating present exponential correlation; the influence of elastic modulus on segment upfloating is far greater than that of the formation cohesion strength and internal friction angle; the formation resilience force caused by shield tunneling, the amount of segment upfloating and the affected height of tunnel upfloating are calculated by force balance theory; finally, the feasibilities of the formulas are verified by case study of Shiziyang Tunnel. The results can provide a new theory and method for predicting the shield tunnel segment upfloating caused by formation rebound.