Although modern railway sleepers are generally made of reinforced concrete, they have retained the prismatic shape of the timber sleepers they replaced. While twin block sleepers as used on some railways such as SNCF may be advantageous in terms of reducing track settlements, they have disadvantages including an increased susceptibility of the rails to lose track gauge (move relative to one another) and are not suitable in ground conditions aggressive towards steel.
The aim of this project is to investigate the potential for differently, more efficiently-shaped sleepers to improve track robustness and reduce maintenance needs. Track forms that might be investigated include broader or dumb-bell shaped sleepers, with the bulk of the material placed where support is most needed, segmented ladder and hybrid tracks. The project will include the experimental investigation of sleeper/ballast bed performance over millions of loading cycles in purpose-built test rigs at Southampton and/or Nottingham; numerical discrete element method (DEM) modelling using techniques developed at Southampton and Nottingham to identify micromechanical behaviours and help explain the observed behaviour; and dynamic finite element analyses using suitable continuum models for the ballast and the supporting soil to assess load transfer and other macroscopic effects. There will also be the opportunity to help specify and become involved in field testing of novel track forms and interventions, through the EU-funded Shift2Rail programme. The results will be incorporated into integrated T2F models for improved track performance prediction and maintenance planning.
The Novel Forms of Railway Track research project is part TRACK TO THE FUTURE (T2F) a major five-year, £8M research programme, funded by EPSRC, industry and the Universities of Southampton, Birmingham, Huddersfield and Nottingham. Its aim and vision is to support the development of railway track systems that are efficient in terms of embodied carbon, materials use and cost; robust in requiring little maintenance; and unintrusive in producing little noise. It will address this aim through three interlinked Research Challenges RC.
TRACK4LIFE (RC1): low-maintenance, long-life track systems with optimised material use, through
• developing, and demonstrating the effectiveness of, new track forms or components and promising interventions e.g. under-sleeper pads and random fibre ballast reinforcement (1A)
• developing an understanding of the relationships between the key measurable parameters of track stiffness and track settlement, and the key performance parameter of geometrical standard deviation, taking into account the interactions with rail geometry and vehicle dynamics (1B), and
• extending the life of ballast by reducing or eliminating the factors leading to its degradation, assessing the feasibility of design for the degraded state and facilitating re-use rather than downcycling or disposal (1C).
DESIGNER CROSSINGS AND TRANSITIONS (RC2): crossings and transitions that optimise the behaviour of the vehicles traversing them, thereby minimising damage. This will be achieved by developing new understandings of the highly complex interactions between switch and crossing geometry, sub-base support, wheel profile and vehicle dynamics, including the effects of varying the support stiffness through the crossing or transition; and combining them with the potential of modern manufacturing methods to provide a tuned variation in geometry and materials properties.
NOISE-LESS TRACK (RC3): an integrated approach to designing a low-noise, low-vibration track consistent with reduced whole life costs and maintenance needs. Track is the main source of railway rolling noise and has a key role in vibration transmission into the ground. Noise is increasingly cited as the main objection to the expansion, reopening or construction of railways. However, design changes are usually driven by other concerns with the implications for noise and vibration considered as secondary effects.
Applications for this PhD research project are accepted on a rolling basis and we therefore advise you to apply early if you are interested. To make your application please go to: http://www.southampton.ac.uk/engineering/postgraduate/research_degrees/apply.page
If you wish to discuss any details of the project informally, please contact Professor William Powrie, Infrastructure research group, Email: [email protected]
, Tel: +44 (0) 2380 59 3214.
This project is being run in participation with the EPSRC Centre for Doctoral Training in Sustainable Infrastructure Systems (http://www.cdt-sis.soton.ac.uk/). For details of our 4 Year PhD programme and further projects, please see http://www.findaphd.com/search/PhdDetails.aspx?CAID=2477
Visit our Postgraduate Research Opportunities Afternoon to find out more about Postgraduate Research study within the Faculty of Engineering and the Environment: http://www.southampton.ac.uk/engineering/news/events/2016/02/03-discover-your-future.page