Investigation of Seismic Behavior of Railway Track in Earthquake Excitation with Various Peak Ground Acceleration Using 3D Numerical Model

Seismic stability of infrastructures against earthquakes is one of the most important engineering challenges in railway transportation systems. Present literature shows that there are many considerable technical shortages in this issue. Therefore a 3D FE model including the beam elements for modeling the rails and sleepers as track superstructures components, a series of lumped masses with spring and dashpot for modeling the ballast, subballast and subgrade as track substructure components and a number of stiffness and damping for considering of longitudinal and lateral resistance was developed. For validation of the model, comparing the results of a shaking table test with seismic analysis outputs of the model is compared. Accordingly this numerical model can be employed for seismic railway track analysis. The influence of earthquake on seismic behavior of railway track by imposing the artificial accelerograms with variation of peak ground accelerations (PGA) from 200gal to 1000gal was studied. For above mentioned assessments, the operational conditions including longitudinal and lateral deflections of track, as well as structural conditions consisting of axial forces, shear forces and bending moments of rail and sleeper were investigated.