Reliability, availability and maintainability (ram) analysis techniques for railway infrastructure management

Railway track maintenance and renewal (M&R) activities are very important to enable a safe and efficient railway operation. The M&R models of railway tracks can be categorized as periodic, planned, corrective, and condition based techniques. Railway organizations choose one or more of them to realize the maintenance activities in daily or yearly bases. The vertical and horizontal position of railway track is called as railway track geometry. If there is a deviation from railway track geometry, it is named as railway track geometry deterioration. Railway track geometry is mainly investigated in two groups which are horizontal geometry and vertical geometries. The deterioration of railway track geometry is classified as horizontally and vertically track geometry deteriorations. The deterioration of railway track geometry comes up when the track components (Rails, sleepers and ballast layer) deteriorate. European Union put into practice an European standard in 1999 known as EN 50126 to prevent these accidents and ensure a high safety rail operation system. EN 50126 standard aims to provide high secure and safe system for railways. The EN 50126 standard consists of the following concepts which are Reliability, Availability, Maintainability, and Safety (RAMS). In this study, a modal framework is developed for railway infrastructure management including RAM analyses. Railway track components and track geometry parameters were used in this model. The measurements of infrastructure components (Track geometry, rails, sleepers and ballast layer) obtained from the measuring devices were evaluated on the base of the standards. Three threshold values which are Alert Limit, Intervention Limit and Immediate Action Limit were defined for each infrastructure component. A case study was performed for Uzbekistan high-speed railways. In this study, Tashkent and Sirdaryo railway section, which is between Tashkent and Samarkand high-speed railway line, was investigated. The high speed railway section was divided into analysis and maintenance sections for RAM analyses. The RAM analyses were performed by using the data collected from each sections. Consequently, the reliability, availability and maintainability levels of Uzbekistan high-speed railways were obtained and some evaluations were made.