人为因素是导致隧道事故的主要原因，针对已有的人为失误分析模型在量化计算和风险控制方面的不足，提出了改进的SReason分析和控制模型，以减少盾构隧道施工期的风险事故。结合隧道工程的施工特点，该模型相对于现有的SReason模型提出以下2点改进： 1）以人为失误的控制难度权值为度量，找出风险事故的最优控制路径； 2）通过控制最优控制路径中的人为失误截断风险的事故链，同时利用反馈路径实时反馈控制效果。利用该模型对管片密封材料损伤破坏进行了分析，在该风险的最优控制路径上找出了不同层次人员的人为失误，并对人为失误提出了相应的控制措施；通过与常规方法的比较，表明所建模型既重视了组织和个人因素的影响，又兼顾了风险控制的经济性和安全性。

Human factors are the main causes for tunnel accidents and existing human error analysis models have flaws in quantification calculation and risk control. This paper presents the improved SReason analysis and control model, so as to reduce accidents during shield tunnel construction. Keeping in mind the characteristics of shield tunnel projects, the model improves the existing SReason model in two aspects: Firstly, the control difficulty weights of human errors are taken as the measures to find out the optimal control path of the accidents; Secondly, it cuts off the accident chains by preventing human errors in the optimal control path, while managing the end result by supplying feedback constantly through the feedback loop. By means of the said model, the paper analyzed the damage and failure of segment sealing material, disclosed human errors of staff at different levels in the optimal control path, and proposed corresponding control countermeasures. The comparison and contrast between the SReason analysis and control model and conventional methods shows that the improved SReason analysis and control model not only takes the factors of the organizations and the individuals into consideration, but also takes the economic efficiency and the safeness of the risk control into consideration. 