Track geometry for high-speed railways

The present work consists of two main parts. The first part (Chapter 2 and 3) deals with a literature survey where a short introduction is given for track geometry and track/vehicle interaction. After the introduction, a survey over the present standard in Europe and Japan is made. In particular the recent proposals for a common European Standard (CEN) and TSI (Technical Specification for Interoperability) are reviewed. The second part (Chapter 4, 5 and 6) starts with an attempt to foresee the performance of a train that would be available from the industry around 2010. Furthermore, the second part deals with simulations. Firstly, hunting stability is simulated to establish a vehicle configuration that could deal with higher speeds. Secondly, track shift forces are simulated with Prud ́hommes criteria as boundary condition. Thirdly, a risk factor for vehicle overturning was calculated in the most adverse case where the train was running on a curve and the wind was directed outwards. In the simulations, two sets of track irregularities were used. Some consequences of different kinds of freight train operations are discussed in Chapter 7. In short terms, the following conclusions have been drawn: A cant up to 200 mm is possible if the track is built for dedicated high-speed traffic; in freight train operations some 20-50 mm lower. A cant deficiency of 225-250 mm could be allowed when using carbody tilt and suitable bogie technology. The tilt is a basic requirement when using such high values of cant deficiency. The transition curves should be long, i.e. the duration in the transition curve should be in the order of around 4-5 sec, if carbody tilt is anticipated. It could be concluded that hunting stability can be achieved. The track quality has too be improved relative to current standards for 200 km/h in order to meet requirements on lateral track shift forces. The degree of improvement should be further investigated. It is concluded that safety criteria for side-wind exposure can be met, if the trains have favourable, although, realistic, aerodynamic performance. The maximum gradient shall be chosen according to the type of freight traffic foreseen in the future.