Nauka ta progres transportu (Dec 2016)
RIGIDITY OF INTERMEDIATE FASTENING SCREWS AND SPIKES FOR WOODEN SLEEPERS UNDER THE ACTION OF HORIZONTAL LATERAL FORCES
Abstract
Purpose. Despite the steady increase in the length of sections of continuous welded rail on concrete sleepers, wooden railway sleepers, as one of the options of under-rail bearings, are still operated on a sufficiently large number of areas, in particular, remain uncontested in the curve of up to 350m radius, as well as on the main ways of subways. The main types of fasteners in the most common types of intermediate rail fastenings for wooden sleepers are track screws and spikes. Since the «wheel-rail» system contact peculiarities existing in track curved sections have a significant impact on the processes of interaction between the railway track and rolling stock, it is necessary in this work to determine the rigidity of the track screws and spikes, which are directly involved in the formation of spatial rigidity of the intermediate rail fastening nodes under the influence of horizontal transverse forces. Methodology. The study of the track screw and spike rigidity was conducted experimentally for the two types of intermediate rail fastenings – D0 and «Metro». To carry out experimental tests, 10 test sites were selected on the roads of the regional branch of «Southern Railway» of «Ukrzaliznytsia», and 8 – in the main routes of KP «Kharkiv Metro». Each of the test sites was in approximately the same operating conditions, but had different values of passed tonnage. Findings. The values of the track screw and spike rigidity were obtained. Originality. The authors first obtained the experimental data on variation in rigidity of track screw and spike, depending on the useful life for the main railways and subway routes. This allows calculation of the horizontal shear forces in track curved sections (particularly in curves of up to 350 m radius), as well as the forecast evaluation of their level change during operation. Practical value. Based on the experimental data, it was found that variation in rigidity of track screw and spike depending on the lifetime is nonlinear. These experiments allow a more rational approach to the issue of determining the optimal design of the intermediate rail fasteners, based on the specific operating conditions, and may also contribute to the development of measures to improve the reliability of the components of intermediate rail fastenings for wooden sleepers.
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