Dynamic Analysis of Railway Bridges under High Speed Trains

The interest in dynamic behavior of railway bridges has increased in recent years with the introduction of high speed trains. Higher speeds of the trains have resulted in larger and more complicated loads than earlier, producing significant dynamic effects. The dynamic aspects are of special interest and have often shown to be the governing factor in the structural design. Dynamic analysis of railway bridges is, therefore, required for high train speeds. The objective of this paper is to investigate the dynamic behavior of an existing railway bridge subjected to high speed trains. A railway bridge model has been developed to study dynamic effects such as oscillations produced by moving loads of constant magnitude and to obtain a relation between the velocity, acceleration, load position and deflection of the bridge at any instant of loading, with and without damping, with the help of MATLAB software. The simulation results indicate that the speed of the vehicle is a very important parameter influencing the dynamic response of a railway bridge. The amplitude of bridge deflection has been found to be the highest at speeds between 75 and 85 m/s. Further, the introduction of damping has been found to greatly influence of the amplitude of bridge deflection response. However, the peak deflection values appear at the same speed independent of the damping coefficients.