为明确下穿人工湖地铁盾构隧道结构下沉变形原因，并对变形后盾构隧道结构安全进行评估，以某人工湖受极端天气影响水位快速上升后，下穿人工湖的地铁盾构隧道产生沉降为例展开研究。首先通过荷载结构模型对盾构隧道强度进行验算，然后采用地层结构模型模拟盾构隧道上方堆载及卸载工况对盾构隧道变形的影响，并与现场监测数据进行对比分析。结果表明：人工湖水位上升为盾构隧道变形下沉的主要原因，产生变形后隧道结构自身承载能力及裂缝宽度均满足设计和规范要求，盾构隧道结构自身是安全的，同时对人工湖抽水后隧道上浮值进行预测，盾构隧道结构在上浮后仍然处于安全状态，研究成果可以为后续人工湖及地铁隧道处理措施提供参考依据。

Owing to extreme weather, the water level of an artificial lake rises rapidly, and the subway shield tunnel passing through the artificial lake subsides. The reasons for the subsidence deformation of the subway shield tunnel structure were studied, and the structural safety of the shield tunnel after the deformation was evaluated. The deformation of the shield tunnel was analyzed by examining the monitoring data on-site, and using the load structure model to check the strength of the shield tunnel, and the stratum structure model simulating the loading and unloading conditions above the shield tunnel. The calculation results showed that the rising water level of the artificial lake was the main reason for the deformation and sinking of the shield tunnel. After the deformation occurred, the bearing capacity and crack width of the tunnel structure met the design and specification requirements of the shield tunnel, and the shield tunnel structure itself was still safe.

U231.1