在隧道盾构施工过程中，盾构被困的现象时有发生，对工程施工进度、安全和周围环境等造成不利影响。通过工程实例分析刀盘、盾体和盾尾被困的常见原因，总结相应的脱困措施，得出盾构被困的分类判断依据： 1）刀盘开口处被地层中异常渣土填充束缚的判断依据； 2）边刀（边滚刀或边刮刀）磨损造成掌子面开挖轮廓不足的判断依据； 3）刀盘前方存在硬质障碍物的判断依据。

Shield is often jammed during tunneling, which has adverse impact on construction schedule, security and environment. The causes of cutterhead jamming, shield body jamming and shield tail jamming are analyzed; and then corresponding releasing technologies are summarized by cases study. The classification characteristics of shield jamming are summarized as shield cutterhead covered by grout, insufficient excavation contour of tunnel face caused by marginal cutters wear and obstacles in front of cutterhead.