Metro shield tunnels in soft soils often exhibit uneven settlement, which causes leakage, cracking, dislocation, and bolt failures. Excessively uneven settlement affects the safety and durability of a tunnel structure and aggravates the track irregularity, thereby impeding operational safety, ride comfort, and steady function. As ride safety and comfort are more sensitive than tunnel structure safety to uneven settlement, they can potentially be used as indexes for the early warning of uneven settlement. Accordingly, a 20 m long metro rail car model with 10 degrees of freedom was established, and its behaviors were analyzed under different settlement amplitudes and running speeds. The results indicated that the rail car operational comfort index was more sensitive than the safety index to uneven settlement. An early warning value was then determined on the basis of the comfort index ranges for settlement length and vehicle speed, enabling the development of an early warning strategy for uneven settlement. The proposed strategy was subsequently applied to a case study, which monitored the uneven settlement of an interval of a metro shield tunnel using inclinometers.

在软土中的地铁盾构隧道通常表现出不均匀沉降，这会导致泄漏，开裂，错位和螺栓损坏。过大的不均匀沉降会影响隧道结构的安全性和耐用性，并加剧轨道不平顺性，从而影响操作安全性，乘坐舒适性和稳定功能。由于行驶安全性和舒适性比隧道结构安全性对不均匀沉降更敏感，因此它们有可能被用作不均匀沉降预警的指标。因此，建立了一个具有10个自由度的20 m长的地铁轨道车辆模型，并分析了在不同沉降幅度和运行速度下的行为。结果表明，有轨车的运行舒适度指标比不安全指标对不均匀沉降更敏感。然后，根据舒适度范围的沉降长度和车速确定预警值，从而能够开发出沉降不均匀的预警策略。提议的策略随后应用于案例研究，该案例使用倾角计监测地铁盾构隧道间隔的不均匀沉降。