Influence of Pier Stiffness on Track-Bridge Interaction

Abstract

The bridge is a common engineering structure over which a rail track is often laid. With the introduction of continuous welded rail (CWR), major rail tracks have shifted worldwide from jointed rail to continuous welded rail. CWR eliminates fish plates and overcomes many of the drawbacks of the jointed rail, resulting in a long, smooth track with no joints. Track-bridge interaction (TBI) is important when a continuous welded rail is provided over a bridge structure. Since numerous parameters influence the phenomenon, a numerical model has been developed in SAP2000. Longitudinal pier/abutment stiffness is an important structural property of bridge substructure, and its magnitude changes significantly from one bridge to another. Due to the coupling between CWR track and the bridge, the bridge pier stiffness affects the rail stress developed in addition to pre-existing stress. Pier stiffness has been identified as an important parameter affecting the track-bridge interaction phenomenon as its value changes with the site conditions. The developed numerical model has been utilized to study the influence of pier stiffness on support reaction and additional rail stress in CWR subjected to thermal loading. Both the support reaction and rail stress have been found to be considerably influenced by pier stiffness. Additional rail stress in CWR is a source of concern because the track is a long, slender member that can buckle if excessive compressive stress develops in the track.