Catastrophe theory-based risk evaluation model for water and mud inrush and its application in karst tunnels

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.