Wave Propagation Law And Blast Overpressure Model For Explosion In Subway Station

Subway is a newly developed communication media, which emerges as the times require. Subway has been greatly developed in many countries of the world for its unique superiority. However, blast accidents occur frequently in subways nowadays all over the world. Once explosion happens in the subway station, it might lead to strong dynamic response of the structure, progressive collapse and even the damage and destruction of the buildings on the ground, which seriously threatens the safety of lives and properties. In order to study the blast effect on the structures, the propagation of the blast wave in the subway station and the blast load on the structure should be studied.Aiming at the complex environment of the subway station, this paper analyses the propagation of the blast wave with Euler method using software AUTODYN, which is based on the hydrodynamic theory and the explosion mechanics. The primary work includes:(1) Three-dimension models are established to simulate the blast phenomenon of 20kg-TNT-explosion in the underground subway station, and to study the blast overpressure and impulse attenuation in longitudinal dimension and distribution in vertical dimension. The blast effects on the nearby columns are also studied.(2) In order to study the blast effects on the surrounding soil and buildings on the ground near the station, a 200kg-TNT-explosion in the subway station is numerically simulated to study the shape, the attenuation and the arrival time of the blast wave.(3) Series of related two-dimension longitudinal section models are established to investigate the effects of TNT charge weight, station height and location of the exit on blast wave propagation.Based on the numerical results, some main conclusions are drawn as follows: Confined by the structure in the complex environment of the subway station, the overpressure and the duration of the blast wave increase. A simplified model of the blast overpressure is proposed. It can be used to study the blast effects on the surrounding soil and the buildings on the ground in large explosion. The key parameters of the subway station such as the height of the section, the location of the exit and the charge weight of the TNT have great influence on the propagation of the blast wave and the distribution of the blast overpressure.