Risk Assessment of Diversion Tunnel Construction Based on GRA-EWM-MEE Model

In order to accurately predict the level of landslide and water surge risks during the construction phase of the diversion tunnel, a scientific and reasonable assessment of the tunnel construction safety risks was carried out by combining game theory and the matter-element expansion method. Considering the various predisposing indexes of the tunnel, an index system containing 24 indexes was constructed by combining relevant codes and references. GRA and EWM are used to assign subjective and objective weights to the indexes respectively, and game theory is used to determine the weights comprehensively. The GRA-EWM-MEE model was established based on the matter-element extension method and validated with tunnel 7# as an example. The results show that the correlation degrees of each section of the tunnel are: 0.086, 0.069, 0.033, 0.035, and 0.077, all of them belong to class II (moderate risk), which is consistent with the results of the variable fuzzy set evaluation and engineering risk assessment report. Therefore, it is feasible to apply the model to tunnel construction risk assessment, which can provide new ideas for the safety risk assessment of similar diversion tunnels.