Assessing the effects of track input on the response of insulated rail joints using field experiments

Abstract

Manufacturers of insulated rail joints (IRJs) have to follow the quality assurance regime stipulated in the national design standards; unfortunately, IRJs still exhibit a very low and highly variable service life. It is widely believed that the service life of IRJs is affected by the track input under the passage of loaded wheels; however, there is a paucity of literature with regard to the actual mechanical behaviour of IRJs in the track. An extensive field test was, therefore, conducted on an in-service heavy haul corridor in Australia with the specific aim of understanding the effect of the track input on the response of the IRJs. Data on the wheel–rail force, rail/joint-bar strain, sleeper acceleration and ballast pressure signatures in the time domain were determined from the experiment. This data was subsequently systematically analysed to compare the relative structural merits of two IRJs resting on different sleeper spaces and a reference continuous rail subjected to similar real-life coal traffic loading.