Study On Casualties Prediction And Emergency Management Of Metro Train Under Blast Impact

The space of the subway train compartment is small and the population is dense.In the event of an explosion,casualties and property losses will follow,resulting in negative social impact.In the subway train,it is very important to study and predict the casualty area after the explosion.The methods used in this paper include theoretical analysis,software numerical simulation and engineering examples to verify the theory.The research method is used to analyze the casualty area and emergency management,and some achievements have been made.(1)In this paper,the generation and development of blast wave are studied,and the three evaluation criteria of overpressure,impulse and overpressure-impulse are compared and analyzed,and the overpressure-impulse criterion is more suitable for the analysis of subway train explosion casualties.Based on the psychological representation model of people’s panic,the panic correction coefficient was introduced.Through the method of injury judgment and the process of judging the injury,the prediction model of explosion casualties is established.(2)Through the understanding of numerical calculation,the propagation form of shock wave after the explosion of subway car is simulated and the propagation law is predicted.Multiple reference frames are selected in the interior of the car to quantitatively study the shock wave energy curve in each reference frame,so as to obtain the peak value of the waveform,the number of peaks and troughs,and the duration of action.At the beginning of the explosion,the waveform of shock wave is regular and spherical.When the shock waves encounter obstacles,different shock waves will gather.After a period of time,the energy of shock wave will be weakened,and the waveform will become the form of plane wave.(3)Through the study of the shock wave at each reference point,the unfavorable position of the explosion interface appears,the order from large to small as follow:the bottom corner of the train > the bottom > the top corner > explosive horizontal sidewall > the top of the train;the closer to the detonation source,the blast wave presents the characteristics of "high peak pressure,less wave peaks and duration".The farther away from the explosion center,the explosion shock wave presents another form." less peak pressure,more wave peaks and long duration of action".(4)Taking the Moscow metro explosion as an example,the overpressure peak and impulse distribution characteristics of the blast shock wave were analyzed,and the death,serious injury and minor injury regions were preliminarily determined based on the overpressure-impulse criterion.The casualty area was modified by using the panic state model.Compared with the actual accident case,the model is proved to be effective.(5)The importance of emergency management to reduce subway casualties has been demonstrated by analyzing Moscow metro and London metro explosion cases.Based on the 4R theory,this paper analyzes the shortcomings of the terrorist attack in the subway train,puts forward countermeasures and suggestions,and compiles the disposal process of the terrorist attack in the subway train.