Numerical Research On Influence Of Railway Protective Wall On Blast Wave Propagation

All kinds of explosion accidents and terrorist explosion attacks occur frequently along the railway,which seriously threaten people’s life and property safety.Railway protective wall can reduce the impact of explosion shock wave on train and personnel safety to a certain extent.Therefore,it is of great significance to study the aerodynamic response of railway protective wall and train under the action of explosion shock wave and explore the dynamic response of railway protective wall.This paper establish the explosion shock wave – train – railway protective wall coupling system simulation model,the explosion shock wave in the railway protective wall and train a numerical simulation of the aerodynamic response under the action of explosion shock wave propagation is studied and the rail pressure distribution on the surface of the protective wall and train,and compared the influence of different factors on the pressure distribution.According to the concrete structure design specification,the solid structure model of railway protection wall is established,and the fluid-structure coupling method is used to analyze the dynamic response of railway protection wall.According to the displacement time history curve,the influence of the relative position of explosive and railway protective wall,explosive amount,reinforcement ratio and thickness of railway protective wall on its dynamic response degree is analyzed.The results show that:(1)the railway protective wall has obvious effect on reducing the explosion shock wave,the aerodynamic pressure on the train surface is positively correlated with the explosive amount,and negatively correlated with the height of the railway protective wall,and the horizontal distance between the explosive and the railway protective wall has a non-monotonic change on the aerodynamic pressure on the train surface.(2)The aerodynamic pressure on the surface of the railway protective wall is positively correlated with the amount of explosives,and negatively correlated with the height of explosion and the horizontal distance between explosives and railway protective wall.When the horizontal distance between explosive and railway protective wall is less than 4m,the peak value of overpressure in the vertical direction of explosion facing railway protective wall changes significantly(3)If the height of the railway protective wall minus the vertical distance between explosive and ground is the Angle α,when α > 26.56°,α is negatively correlated with the maximum flow pressure behind the railway protective wall,when α < 26.56°,α is positively correlated with the maximum flow pressure behind the railway protective wall.(4)The stress and strain of the axis of symmetry relative to the explosive center and the area at the bottom of the railway protection wall are the largest,and the displacement,acceleration and velocity of the axis of symmetry and the area at the top of the railway protection wall in the X direction are larger than those of other positions at the same time,and are symmetrically distributed,and the displacement changes have reciprocating swing.(5)The displacement of railway protective wall is positively correlated with the amount of explosives,and negatively correlated with the horizontal distance between explosives and railway protective wall,the height of explosion,reinforcement ratio and thickness of railway protective wall.Appropriately increasing the thickness of railway protective wall is an effective measure to improve anti-explosion performance.