Service Condition of Railroad Corridors around the Insulated Rail Joints

Abstract

Railroad corridors contain a large number of insulated rail joints (IRJs) that act as elements (critical to safety) in the circuitries of signaling and broken rail identification systems. IRJs are regarded as sources of excitation for the passage of loaded wheels that lead to high-impact forces. These forces in turn cause dips, cross levels, and twists to the railroad geometry in close proximity to the sections that contain IRJs, in addition to local damage to the railhead of the IRJs. Therefore, a systematic monitoring of IRJs in railroads is prudent to mitigate the potential risk of their sudden failure (e.g., broken tie plates) as a consequence of rail traffic. This paper presents a simple method of periodic recording of images using time-lapse photography and total station surveying measurements to understand the ongoing deterioration of IRJs and their surroundings. Over a 500-day period, data were collected to examine the trends in narrowing of the joint gap that is attributable to plastic deformation of the railhead edges. Data was also collected with respect to the dips, cross levels, and twists that were imparted to the railroad geometry, which is attributable to the settlement of ties (sleepers) around the IRJs. The results reflect that the average progressive settlement beneath the IRJs is larger than that under the continuously welded rail, which leads to excessive deviation of the railroad profile, cross levels, and twists.