Flow Field Distribution And Dynamic Response Analysis Of Typical Subway Structure Subjected To Internal Explosion

Subway is one of the main objectives of terrorist attacks, for its closed and somany people. There is few research about subway structure subjected to internal blast.In term of theoretical analysis and numerical simulation, the flow field distribution,casualties, dynamic response and damage of structure have been studied, for the subwaystructure subjected to internal explosion. The main results are as follows:1. A numerical model is built to simulate the blast propagation inside subwaytunnel, which is testified through the comparison between the numerical simulationresults and explosion tests, for outside and inside tunnel. And blast propagation insidetypical subway tunnel has been studied. The effects of parameters on the pressuredistribution at the tunnel structure, including explosive charge, stand off and theexplosive location, have been investigated. By the method of dimensional analysis andnumerical simulation, an attenuating formula has been proposed for evaluation ofoverpressures. And its applicability is verified by comparison with the other availableformulas.2. For the typical subway station subjected to internal explosion, flow fielddistribution and the isobar of overpressure at the station platform under differentexplosive charge have been studied. Based on the collected criteria domestic and abroadof injured people, casualties in the subway station are estimated and shown in figures inwhich different areas are divided by different injured levels.3. The methods to parameters of different concrete constitutive, has beensummarized. By comparing the different concrete constitutive, method is proposed todetermine concrete constitutive parameters. A numerical model to simulate the structuresubjected to blast loading is estabilished and whose parameters are testified by existingtest. The model can be applied to the analysis of subway structure subjected to inernalexplosion.4. A "explosive-air-structure-geo" dynamic interactive numerical model isproposed for internal blast dynamic analysis of typical tunnel structure, combined withviscous-spring artificial boundary. The dynamic response and damage of tunnelstructure are analysed by the numerical model.5. A damage evaluation index, based on the load capacity of column, has been presented. The damage of column subjected to blast is estimated by using the damageindex. The influence of columns parameters, such as concrete strength, longitudinalreinforcement ratio, transverse reinforcement ratio, axial load and the height ofexplosive, on the damage index of column subjected to blast is analysed. And the FRPand steel are suggested to strengthen the column against the blast loading.6. For the underground structure subjected to internal blast, a multi-scale idea andmethod is proposed. The papers adopts the multi-scale method to analyze the dynamicresponse of a typical subway station structure subjected to internal blast.