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

Abstract

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.