This paper presents a risk evaluation model of water and mud inrush for tunnel excavation in karst areas. The factors affecting the probabilities of water and mud inrush in karst tunnels are investigated to define the dangerousness of this geological disaster. The losses that are caused by water and mud inrush are taken into consideration to account for its harmfulness. Then a risk evaluation model based on the dangerousness-harmfulness evaluation indicator system is constructed, which is more convincing in comparison with the traditional methods. The catastrophe theory is used to evaluate the risk level of water and mud inrush and it has great advantage in handling problems involving discontinuous catastrophe processes. To validate the proposed approach, the Qiyueshan tunnel of Yichang-Wanzhou Railway is taken as an example in which four target segments are evaluated using the risk evaluation model. Finally, the evaluation results are compared with the excavation data, which shows that the risk levels predicted by the proposed approach are in good agreements with that observed in engineering. In conclusion, the catastrophe theory-based risk evaluation model is an efficient and effective approach for water and mud inrush in karst tunnels.

本文提出了岩溶地区隧道开挖涌水和泥石流的风险评估模型。为了确定这种地质灾害的危险性，研究了影响岩溶隧道水和泥浆涌入可能性的因素。考虑到水和泥浆涌入造成的损失，以考虑其危害性。在此基础上，建立了基于危险－危害度评价指标体系的风险评价模型，与传统方法相比，更具说服力。突变理论用于评估水和泥浆涌入的风险水平，在处理涉及不连续突变过程的问题时具有很大的优势。为了验证提议的方法，以宜万铁路的月岳山隧道为例，采用风险评估模型对四个目标路段进行了评估。最后，将评估结果与开挖数据进行比较，这表明所提出的方法所预测的风险水平与工程中所观察到的风险水平具有良好的一致性。综上所述，基于突变理论的风险评估模型是一种有效的岩溶隧道突水突泥方法。