ABSTRACT
Track transitions such as at bridge approaches often require additional maintenance activities due to excessive track geometry degradation, mud pumping, and/or track component failure, especially in a high tonnage heavy axle load environment. For a revenue service track in the western United States, some bridge locations required localized maintenance work on a quarterly basis and in the worst case needed slow order train operations before problems were addressed. The root causes of the problems were investigated. Several remedies were implemented to (1) reduce track stiffness and increase track damping for the track on the bridges, (2) improve track drainage, and/or (3) reduce ballast pressure/track settlement for the track in the approaches. With these remedies, long-term track performance was significantly improved with respect to reduced track degradation/differential settlement as well as from improved vehicle-track interaction, resulting in significant benefits from reduction of slow orders, train delays, and major track maintenance activities. This paper provides a summary and update of the remedies implemented to address bridge approach problems in this high tonnage heavy axle load track in the western United States from 2007 to 2016.
