为验证经验中盾构（全断面隧道掘进机）尾刷密封的承压能力，探究影响尾刷密封承压能力的主要因素和失效路径，采用原理分析法和模拟试验法，引入“尾刷密封单元”和“尾刷密封系统”的概念，全面分析尾刷密封构成要素和承压原理，分析、对比盾尾油脂耐压试验与“尾刷密封单元”承压能力的差异，并结合失效案例，推断影响承压能力的主要因素。根据推断模拟尾刷密封一般工况设计试验方案，发现： 1）“尾刷密封单元”承压失效的主要形式为压力水透过盾尾刷焊接结构孔隙和弹簧板拼接缝孔隙，沿盾尾油脂与盾体内壁黏合不充分的地方贯穿失效； 2）验证在试验所代表的技术条件下，1个“尾刷密封单元”的承压能力约为0.2 MPa及多个“尾刷密封单元”承压能力可叠加特性的正确性，直观地发现限制“尾刷密封单元”承压能力在0.2 MPa的主要原因为易形成贯穿缝，为研究和设计更高承压能力的“尾刷密封系统”提供较有力的证据支撑。

To investigate the bearing capacity of the tail brush seal of shields and explore the main factors and failure paths that affect the bearing capacity of the tail brush seal, the principle analysis and simulation test methods are used to comprehensively analyze the components and pressure bearing principle of the tail brush seal and introduce the concepts of "tail brush seal unit" and "tail brush seal system". Next, the difference between the tail grease pressure resistance test and the bearing capacity of a "tail brush seal unit" is analyzed. Furthermore, the main factors affecting the bearing capacity are deduced based on seal failure cases. Finally, a test scheme based on the general working conditions of the tail brush seal is designed. The following are the main results of the study: (1) The main failure of the "tail brush seal unit" is caused by pressure that permeates through seams of the shield tail brush welding structure and spring plate joint and penetrates along the insufficient adhesion between the tail grease and inner wall of the shield structure. (2) A "tail brush seal unit" experiences a pressure of 0.2 MPa; the pressures of multiple "tail brush seal units" can be stacked up, resulting from penetration joints. These results provide a basis for research and design of a "tail brush seal system" with higher bearing capacity.