隧道施工瓦斯风险评估是保证穿越瓦斯段隧道安全建设的关键性问题之一。针对隧道建设过程中的勘察、设计与施工3个阶段，采用解释结构模型揭示了以上3个阶段瓦斯风险影响因素的层次关键，建立风险评估层次模型，明确了风险评价指标的权重计算方法，结合资料搜集、文献整理与工程调研，基于隶属度理论提出风险评价指标赋值标准，构建了隧道建造过程瓦斯风险评估方法。并结合工程实例，验证提出方法的合理性。结果表明：勘察阶段孕险环境为前置条件，勘察扰动为诱发因素；设计阶段孕险环境为前置条件，设计因素为诱发因素；施工阶段孕险环境为前置条件，施工扰动为诱发因素，现场管理为根本原因；勘察阶段揭露了风险，设计阶段降低了风险，施工阶段保证了安全；所提出的方法与现场揭露情况一致，验证了所提方法的合理性。研究成果可以为隧道穿越瓦斯区的风险确定提供理论依据，为后续工程措施的选取提供参考。

Gas risk assessment of tunnel construction is one of the key issues to ensure the safe construction of tunnels passing through gas sections. Aiming at the three stages of investigation, design and construction in the process of tunnel construction, the interpretative structural model was used to reveal the hierarchical key of gas risk influencing factors in the above three stages. The hierarchical model of risk assessment was established, and the weight calculation method of risk assessment index was defined. Combined with data collection, literature collation and engineering investigation, the assignment standard of risk assessment index was proposed based on membership degree theory, and the gas risk assessment method in tunnel construction process was constructed. Combined with engineering examples, the rationality of the proposed method was verified. The results show that the pregnancy risk environment in the survey stage is the precondition, and the survey disturbance is the inducing factor. The pregnancy risk environment in the design stage is the precondition, and the design factor is the inducing factor. In the construction stage, the pregnancy risk environment is the precondition, the construction disturbance is the inducing factor, and the site management is the root cause. The risk is revealed in the survey stage, the risk is reduced in the design stage, and the safety is ensured in the construction stage. The proposed method is consistent with the on-site disclosure, which verifies the rationality of the proposed method. Through the above research, it can provide a theoretical basis for the risk determination of the tunnel crossing the gas area, and provide a reference for the selection of subsequent engineering measures.