Search

The long-term behaviour of railway track has attracted increasing attention in recent years. Improvements in long-term structural performance reduce demands for maintenance and increase the continuous availability of railway lines. The focus of this paper is on the prediction of the sensitivity of a track design to long-term deterioration in terms of track geometry. According to the state of the art literature, degradation is often investigated using empirical models based on field measurement data. Although a rough maintenance forecast may be made employing empirical models, the predictions are not generic, and the physical processes which govern track degradation under train operation remain unclear. The first aim of this study is to present a mathematical model to elucidate the underlying physics of long-term degradation of railway tracks. The model consists of an infinitely long beam which is periodically supported by equidistantly discrete sleepers and a moving unsprung mass which represents a travelling train. The mechanical energy dissipated in the substructure is proposed to serve as a measure of the track degradation rate. Secondly, parametric studies on energy dissipation are conducted to identify effects of various track design parameters on the susceptibility of the track to degradation, as well as the effect of the train speed. It has been shown that the track/subgrade stiffness is the most influential parameter on degradation whereas other system parameters do influence the degradation rate but at lower magnitudes. The conclusions can be used to optimise the track design in the early stage for better long-term structural performance of railway tracks.

Byline: Arjen Zoeteman Infrastructure managers increasingly have to deliver to defined performance levels, related to system reliability, availability and life cycle costs, as a result of increasing pressures from governments and operators. This paper will investigate the consequences of this development for the newly established European Railway's infrastructure managers (IMs). It particularly focuses on the state of the art in the maintenance planning process. IMs have difficulty in adapting to the quickly changing expectations on reliability and affordability. Several methods and tools for asset maintenance management have been developed, but their application in practice is still scarce. Significant challenges currently being tackled are the design of computerised maintenance management systems and their implementation in a traditionally fragmented (budget-driven) maintenance organisation.