Evaluation of the Effect of Loose Bridge Bearing on Onboard Measured Track Geometry Using Numerical Analysis

Abstract

Detection of loose bridge bearings with an uplift gap in steel bridges requires visual in situ inspection, which is labor-intensive. This study investigated the effect of loose bearings on track geometry using numerical calculation, as part of a fundamental investigation into detecting loose bearings using track geometry. A non-linear spring representing the loose bearing was introduced into the existing calculation tool, identifying the loaded track geometry considering the structural deformation. Results of a simulation using this tool clarified that the displacement of loose bearings appears in track geometry as a local fluctuation with a half wavelength of about 5 m, regardless of the size of the uplift gap at the loose bearing.