Risk Assessment for Water Disaster of Karst Tunnel Based on the Weighting of Reliability Measurement and Improved Extension Cloud Model

Risk assessment of water disaster in karst tunnels is a nonlinear, complex, and uncertain system problem. Based on the reliability measurement method and extension cloud theory, the reliability measurement weighting and improved extension cloud model are established for the risk assessment of water disaster in karst tunnels. Firstly, on the basis of fully considering the relevance of evaluation indicators, a dynamic weighting theory for reliability measurement of indicators based on Jousselme distance is proposed. Secondly, according to the two different entropy algorithms of the extension cloud model, an improved extension cloud model is proposed based on the entropy algorithm fusion of game theory. The comprehensive cloud correlation degree obtained by the improved extension cloud model is combined with the indicator reliability measure weight. Then, the dangerous state of the water disaster in karst tunnels is judged, and the visualization of the water disaster level judgment is realized. And the model is tested with sample data from six typical karst tunnels. Finally, the model is applied to the Yangpeng Karst Tunnel on the Beijing-Zhuhai expressway. The results show that the water disaster level of the tunnel is I, and the evaluation results are consistent with the actual situation. Compared with the matter element extension model and the extension cloud model, the calculation results are more accurate. The corresponding treatment measures have been taken, and the good effect of water disaster treatment has been achieved. The practical value of the model is further proved, and a new reference method is provided for the prediction and prevention of water disaster in karst tunnels.