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Parameters for track design
Published in Buddhima Indraratna, Trung Ngo, Ballast Railroad Design: SMART-UOW Approach, 2018
Buddhima Indraratna, Trung Ngo
The rail track network forms an important part of the transportation infrastructure in Australia. It plays a significant role in maintaining a healthy economy by transporting export-oriented heavy bulk freight (coal, minerals and agricultural products) and carrying passengers between major cities and from various inland terminals to ports. With increasing competition from other means of transport such as trucks, buses, aircraft and ships, the railway industry must continually upgrade the track system and apply innovative technologies to minimise the cost of construction and maintenance, as well as increase passenger comfort. Salim (2004) showed that Australia has more than 43,000 km of narrow, broad, standard and dual gauge ballasted rail tracks (Fig. 2.1). In Australia, millions of passengers travel in trains every year, particularly in the state of New South Wales (NSW). According to reported data (RailCorp 2010–2011), around 300 million passengers travelled by train during the financial year 2010–2011, and growth in CityRail passenger journeys increased by 1.8% in this year, leading to an approximate increase of 10% compared to 2005.
Vertical Dynamic Train/Track Interaction - Verifying a Theoretical Model by Full-Scale Experiments
Published in Kl. Knothe, St.L. Grassie, J.A. Elkins, Interaction of Railway Vehicles with the Track and its Substructure, 2018
A track structure consists of the rails, sleepers or ties, pads, fastenings, ballast and subgrade. Depending on what is going to be studied, these components may be modelled in a simple or a more complicated manner. The rail may be modelled either as an ordinary Euler-Bernoulli (E-B) beam or as a Rayleigh-Timoshenko (R-T) beam. The R-T beam theory includes rotatory inertia and shear deformation of the beam. In a state-of-the-art paper by Knothe and Grassie [4] they state that shear deformation of the rail can be neclected only for frequencies below 500 Hz.
Maintenance Methodologies Embraced by O&M Department for Track Geometry at Kochi Metro Rail Limited, India: A Case Study
Published in Krishna Kumar, Gaurav Saini, Duc Manh Nguyen, Narendra Kumar, Rachna Shah, Smart Cities, 2022
Priyanka Prabhakaran, S. Anandakumar
As per the standard clause of maintenance, works on tracks are subdivided as scheduled, non-scheduled, renewal. Scheduled maintenance is into preventive and regular maintenance. Maintenance of fixed railway infrastructure typically results in up to 70% of the total cost of the lifecycle of infrastructure assets divided [5]. Non-scheduled maintenance is divided into corrective and temporary maintenance. The scheduled maintenance of track should fit within clearly defined cycles and includes minor interventions such as lubrication, tightening of bolts, Cleaning, etc. The later mentioned aims to restore the track condition to utilize it within permissible tolerances. The above-mentioned consists of interventions in the track geometry or track component defects. This frequently involves correction of equipment position, localized renewals, fasteners tightening, etc. Predictive maintenance is a practice that allows for the identification of irregularities on the track before they reach a critical state. Non-scheduled maintenance accommodates the entire repair done whenever unexpected action arises due to the operation of the train, which includes rail fracture, broken fastening, or defective insulating joints. Renewals are considered to be the final hand phenomena when corrective maintenance is found to be technically ineffective or uneconomical. Renovation involves the replacement of rail pads, fastenings, ballast, buffer stops. Track geometry degrades with age and usage and can affect track performance and safety negatively. When track geometry degrades to an unacceptable level, it can lead to derailment [6]. They are planned well in advance when maintenance expenses become too high. Track maintenance is carried out usually in cycle’s namely weekly inspection, fortnightly inspection, six months intervention, and yearly intervention.
Allocation of effective maintenance limit for railway track geometry
Published in Structure and Infrastructure Engineering, 2019
Hamid Khajehei, Alireza Ahmadi, Iman Soleimanmeigouni, Arne Nissen
Periodic inspections of the track are conducted to monitor the quality of the track geometry over time. In the present case study, although the inspection interval was constant, a sensitivity analysis was performed to assess the impact of different inspection periodicity on the mean number of maintenance actions and the total maintenance cost. The effects of five different inspection intervals were investigated. As mentioned in Section 4.3, a range of limits could be selected as effective ALs. In the sensitivity analysis performed on the inspection interval, the effective AL was set to 1.5 mm and the rest of the specifications were kept constant during all the analysis. For the analysis it was assumed that performing inspections would not affect the serviceability of trains, even inspections executed with a high frequency (i.e. every month).
Reliability, availability and maintainability analyses for railway infrastructure management
Published in Structure and Infrastructure Engineering, 2019
Shuhratjon Hidirov, Hakan Guler
The costs associated with railway track maintenance and renewal (M&R) are important and constitute an important part of the total infrastructure costs. The measures reducing these costs provide an important productivity in railway infrastructure management. The problems of when, where and how the interventions to be made to the railway track, the best allocation of resources and the minimization of costs are very complicated because the same or different track sections under dynamic train loads act in different ways in time. For that reason, the decisions on the M&R works are technically and economically related to each other. The M&R plans are based on the large quantities of technical and economic data, extensive measurement data and also experience. The conventional railway tracks, which have been used for more than a century, consist of rails, sleepers, fastenings, ballast, sub-ballast and subgrade. The conventional railway tracks are referred to as the ballasted railways in the literature. The ballastless railways or slab track using concrete slab instead of ballast layer is also a preferred type of superstructure. The maintenance costs of the ballastless railways are very low compared to the ballasted railways, but their initial construction costs are very high. For that reason, national railway organizations prefer ballasted railways due to low construction costs. Railway organizations have been trying to find an efficient and effective railway infrastructure management system, especially for track M&R works. The corrective maintenance, condition-based maintenance, planned maintenance, preventive maintenance etc. are mostly well-known railway infrastructure management techniques. Railway organizations have been using one or more of these techniques due to their resources and capacities.
Research on causes and countermeasures of wheel polygon wear based on Kik-Piotrowiski contact model
Published in Vehicle System Dynamics, 2023
Zhikun Song, Linjun Guo, Xiaoyi Hu, Di Cheng, Qiang Li
The track system is mainly composed of steel rail, fastener system, track slab, mortar layer, foundation, and other parts. When the vibration of the wheel-rail system is transmitted downward through fasteners and mortar layer, the high-frequency vibration components will be largely attenuated because of the elastic and damping effects of fasteners and mortar layer. Therefore, the structure below the mortar layer can be ignored and can be considered as a rigid body to study the high-frequency vibration of the track system.