NUMERICAL STUDIES ON TRACK-BRIDGE INTERACTION PHENOMENON

Abstract

The increase in speed of trains on the Indian Railways calls for the use of continuous welded rail (CWR) due to its low maintenance cost and avoidance of fractures. However CWR/LWR is associated with track-bridge interaction phenomenon. In European countries UIC code is available to deal with this phenomenon. Unfortunately no such code is available in India and UIC code is not suitable for Indian condition. This has made necessary to investigate the safety of continuous tracks laying on bridge and substructures of existing bridges. Consequently it has become important to estimate additional horizontal reactions on bridge bearing, additional bending stresses in tracks and additional displacements due to track-bridge interaction. For this purpose parametric studies are carried out. The parameters considered are longitudinal stiffness of track in approaches; stiffness of ballast and sleepers; stiffness of support of bridge which includes stiffness of piers and foundation; cross sectional area of rails; types of loading and deck length. In the analysis, rails have been considered to be continuous from approach to approach across the bridge. The stiffness of various elements has been taken with in their practical range adopted by Indian Railways. The modeling for this phenomenon has been performed in ANSYS and STAAD-PRO.The problem is solved by applying boundary conditions to the structure as a whole. A detailed parametric studies for track-bridge interaction phenomenon have been carried out in F.E.M.(finite element method) based softwares i.e. in ANSYS and STAAD-PRO.The practical range of parameters has been considered and effect of each individual parameter on track-bridge interaction has been worked out.