INVESTIGATION OF THE INTERNAL FORCES OF THE FIRST TRACK CONSTRUCTED WITH Y-SHAPE STEEL SLEEPERS UNDER OPERATION IN HUNGARY SUMMARY OF RESULTS OF RESEARCH

The Hungarian State Railways (MÁV Rt.) plans to reconstruct the tracks with short rails and rail joints in its trunk line network by continuously welded rails, that is possible by applying, among other technical solutions, the Y-shape steel sleepers. The first track with Y-shape steel sleepers was constructed in Hungary in November 2003, in the Szabadbattyán - Tapolca railway line at the stop of Badacsony. As a consequence of the application of the Y-shape steel sleepers, a continuously welded rail track has been constructed in a curve with a radius of R=300 m, where previously there had to be rail gaps and rail joints with the concrete sleepers. On behalf of the Hungarian State Railways (MÁV Rt.), the Budapest University of Technology and Economics, Department of Highway and Railway Engineering carried out research series on the track with Y-shape steel sleepers under operation. The series of track measurements had the following aims: 1. to assess the technical parameters of the track with Y-shape steel sleepers, 2. to compare the technical parameters of the Y-shape steel sleepered track with those of a track with concrete sleepers, 3. to determine how these parameters change with time. The track measurements included three series: 1. determining the displacements of the sleepers and the rails under dynamic load of a locomotive, 2. measuring the lateral displacement of the track in a curve, perpendicular to its centre line due to the change of temperature between the variation summer and winter, 3. assessing the graph of the track examination coach. In this paper, the first two subjects will be discussed. The third theme of the research will be investigated in another paper. In Chapter 2, the Y-shape steel sleepers and the tracks constructed with them are described technically in general. The first track section constructed with Y-shape steel sleepers in Hungary is introduced in Chapter 3. Chapter 4 discusses the measurements and their results carried out on the track with Y-shape steel sleepers in Hungary. An evaluation of the results and of the track is given in Chapter 5

Determining the Stress Pattern in the HH Railroad Ties due to Dynamic Loads

This paper deals with the determination of the stress propagation in the HH10 type of steel railroad ties under dynamic loads. The HH10 type of steel ties were tested for fatigue at the University of Illinois at Urbana-Champaign. Simultaneously with the laboratory fatigue tests, I was modelling the stress distribution in the tie due to the dynamic loads with using finite-element software `ABAQUS´. After the introduction, the laboratory arrangement of the tie fatigue test will described in Chapter 2. Chapter 3 details the steps in building up the finite-element model of the `HH´ railroad ties. In Chapter 4, the stress pattern and numerical values for the stresses and displacements of the tie due to dynamic loads as results of the finite-element program will be presented. The most important results will be summarized in Chapter 5

Solutions of Omitting Rail Expansion Joints in Case of Steel Railway Bridges with Wooden Sleepers

The Technical Specifications of D.12/H. of Hungarian State Railways (MÁV) specifies that a continuously welded rail (CWR) track can be constructed through a bridge without being interrupted if the expansion length of the bridge is not longer than 40 m. If the expansion length of a bridge is greater than 40 m, the continuously welded rail should normally be interrupted; a rail expansion joint has to be constructed. The goal of this research is to provide technical solutions of track structures on bridges so a continuously welded rail can be constructed through the bridge from an earthwork without interruption, so rail expansion joints can be omitted

Investigation of internal forces in the rail due to the interaction of CWR tracks and steel railway bridges with ballasted track superstructure

The technical specifications of D.12/H of Hungarian State Railways specifies that a continuously welded rail track can be constructed through a bridge without being interrupted if the expansion length of the bridge is no longer than 40 m. If the expansion length is greater than 40 m, rail expansion joints have to be constructed. The aim of the research is to create finite-element models with which the interaction of continuously welded rail track and steel railway bridges can be calculated and to provide technical solutions of track structures on bridges with ballasted track so rail expansion joints can be omitted

Investigation of the Causes of Railway Track Gauge Narrowing

On behalf of MÁV Hungarian State Railways Ltd., the authors carried out a research and development (R&D) project on behalf of the Budapest University of Technology and Economics, Department of Highway and Railway Engineering, on the subject of “Research and investigation of the causes of gauge narrowing by finite-element modeling in running track and turnout, and under operational and laboratory conditions”. The main objective of the research was to investigate the causes of localized defects of gauge narrowing in railway tracks based on machine and manual track measurements, laboratory measurements, and theoretical considerations. The measures proposed as a consequence of identifying the causes could significantly contribute to reducing the number and extent of local defects in the future. Furthermore, the research aims to develop new theories in less scientifically mature areas and provide procedures and instructions that professional engineers and practitioners can easily apply. The main areas of research, which are not exhaustive, are as follows: (i) the evaluation of the measurement results provided by track geometry measuring and recording cars; (ii) on-site investigations in the railway track in terms of gauge and rail profile measurements; and, based on these, (iii) the selection of concrete sleepers, which were removed from the track and subjected to more detailed geometrical investigations in the laboratory, together with the components of the rail reinforcement; (iv) the track–vehicle connection, tight running in straight and curved track sections under track confinement; (v) modeling of the stability and deflection of the rail when the rail fastenings lose part of their supporting function; and (vi) finite element modeling of the concrete sleepers under operating conditions such as slow deformation of the concrete, temperature variation effects, and lateral support on the ballast. In the already-narrowed track section, the tight vehicle running is not the cause of the track gauge narrowing but a consequence, so it is not investigated in this paper

Investigation of Track Gauge and Alignment Parameters of Ballasted Railway Tracks Based on Real Measurements Using Signal Processing Techniques

This paper deals with the time-frequency characteristic analysis for track geometry irregularities using field data recorded by a comprehensive track inspection train. The parameters of the track gauge and the left and right rail alignment are considered to identify their characteristic wavelengths and the locations of their waveforms. In addition to the conventional time and frequency domain analysis, auto-adaptive signal decomposition techniques are used on four pre-selected track sections. During the time series analysis of the track gauge, the cumulative difference from the mean value is calculated, which makes it possible to distinguish the track section constructed with non-standard initial track gauges. The sensitive wavelengths of the track irregularities are obtained from the proper allocation of wavelength ranges in the Fourier Amplitude Spectrum of the original signal and the Fourier transform of the components detected by the Variational Mode Decomposition. This analysis can elucidate the wavelengths and positions of track irregularities that affect vehicle responses