Propagation characteristics of metro blast wave and prediction of casualty area

Abstract

Abstract A subway train explosion would result in serious casualties because of the narrow space and high crowd density of the subway train. No study has been conducted on the propagation of a blast wave in a narrow space as well as the secondary damage caused by crowd panic. In this study, the propagation characteristics of a blast wave in a subway train were analyzed using the finite element analysis method. The results showed that wave propagation processes can be divided into three phases: spherical expansion, reflection and interference, and propagation along the sidewall of the tunnel. The blast wave generated reflection and interference effects due to the obstruction of the train structure, and the accumulation degree of the blast wave pressure at different positions of the same longitudinal interface differed. In the longitudinal direction of the train, the closer a point was to the center of the explosion, the bigger the peak pressure was, the fewer the crests of the blast wave were, and the shorter the duration of action was. The evaluation model for the explosion casualty was based on the crowd panic effect; the model was validated using the disaster of subway Line 2 in Moscow. The general regression neural network was used to analyze the explosion casualties based on the data of 13 subway train explosions globally; 7 factors that affect explosion casualties were used as indexes. The deviation in the prediction results was less than 20% when the training samples were more than seven. The findings of this study serve as a vital reference for explosion casualty forecast in confined and narrow spaces, subway safety facility setting, and emergency rescue.