No abstract

The influence of rail cant on the overall geometry conditions of railway tracks is assessed both theoretically and experimentally in this study. Extensive data obtained from a light railway line are used for experimental investigations. Modelling of rail—wheel contact using the ADAMS/Rail program is undertaken for theoretical investigations. The need to incorporate rail cant into the development of the track geometry indices is identified, and a method of performing this is proposed. Using this approach, a new track index is defined, for which the main geometry parameters, including alignment, profile, track twist, track gauge, and rail cant (rail twist), are considered. For the development of the new track index, these parameters are combined, assigning justified coefficients to each geometry parameter according to its contribution to the overall conditions of the track. The research methodology and the results are discussed. A practical use of the new index is presented to indicate its capability and applicability.

In this paper, the influence of overloading on the operational life of flexible pavements is discussed, leading to the development of a deterioration model for pavement and a ticketing formulation for overweight vehicles. To conduct this research, a theoretical model is developed for flexible pavements. Using this model, sensitivity analyses are made and the significant parameters that influence the deterioration of pavement under truck loading are investigated. The relationships between the passing loads and the number of allowable load cycles are obtained. These relationships form the basis for further models by which the damage ratios of flexible pavements are assessed and vehicle fines determined. A numerical example is presented to indicate the applicability and practicality of the proposed models.

Rail cant parameter, applied in order to attain suitable movement of wheel on rail, directly influences in dynamic interaction of track-vehicle. In this paper, the effect of geometrical parameters on the behaviour of dynamic interaction of wheel-rail is being investigated through a parametric study. A complex dynamic analyses using ADAMS/RAIL are being applied for one section of actual executed line and the records of geometrical parameters have been registered for this purpose. The necessary measurements have been recorded by KRAB measuring machine, safety levels and serviceability have been controlled based on these data. The results of the analysis show that non-conformity of the rail seat slope relative to its desired value, strictly influences on the coefficient of derailment (about 18 percent), horizontal dynamic forces (about 17 percent), and results in severe rail wear (about 18 percent). However, vertical dynamic forces and safety index are not of any concern form the derailment point of view, since it is within the acceptable range of the standards. The comparison of analyses' results in various operational speeds shows a remarkable impact on the vertical dynamic forces (up to 13 percent) and derailment index (up to 8 percent).

No abstract