Experimental Study on Track-Bridge Interactions for Direct Fixation Track on Long-Span Railway Bridge

Abstract

The rail and track girder of the direct fixation track (DFT) system on the Yeongjong Grand Bridge (YGB) in Korea exhibit integrated behavior. Therefore, unlike the DFT system in general concrete tracks, the track support stiffness (TSS) of the DFT system on the YGB cannot be evaluated with only the displacement of the rail. The actual TSS of the DFT system supported by the flexible track girders was lower than that of the DFT system supported by the general substructure. For this reason, field measurements and a finite element analysis that reflects the actual operating speed of railroad vehicles on the YGB (i.e., Airport Railroad Express (AREX), nonstop Airport Railroad Express (AREX Express), and Korea Train Express (KTX)) were conducted in this study to determine the interactions between the rail and the track girder. The results indicated that the DFT system on the YGB is supported by track girders that exhibit relatively flexible behavior. As a result, the TSS is directly influenced by the bending stiffness of the track girder.