TU Delft, Deltares and ProRail to tackle rail subsidence in a structural way

ProRail, TU Delft and Deltares will conduct an investigation over the next five years into the behaviour of trains travelling along our railway embankments. On 4 October 2021, they signed the RESET research programme agreement for this purpose. This research will focus on the consequences of increased and heavier rail traffic along with climate change on our railway embankments and how we can anticipate them. As there is little fundamental systematic knowledge in this field in Europe, this pioneering research may also assist other countries facing similar problems.

Loads on railway embankments

The rise in mobility over the years ahead will have a major impact on our railways. Railway tracks are laid largely on embankments, so-called track beds: the raised substrate below the track. Eighty per cent of these railway embankments were built before 1920 with the knowledge, requirements and expertise of the time. The coming of heavier and faster trains, and the increase in rail traffic means that these railway embankments are being subjected to increasing loads. This leads to high maintenance costs, operational restrictions and sometimes to incidents. One consequence of this is that it may be necessary to impose speed restrictions on the track on account of the poor quality of the substrate.

Unique partnership

“More and heavier trains travelling means that problems arise with the substrate,” says Karel van Gils, Director of Innovation & Technological Renewal at ProRail. “This research is a unique partnership, with both fundamental and applied research. TU Delft will contribute the theoretical knowledge, Deltares is good at field tests – translating the models into practical applications – and ProRail will look into availability and reliability, etc. This is an integrated approach.” This innovative research project is a unique partnership between TU Delft (geotechnics and railway technology), the business community and the knowledge institution Deltares.

Rolf Dollevoet, Professor of Railway Engineering at TU Delft, adds: “The situation on the track varies from location to location. The results of this research will enable us to determine where the track will have to be reinforced and in what way, based on a differentiated approach, which will yield a sort of recipe book with solutions specific to each track bed.”

Eight doctoral candidates from TU Delft will work on the project. Deltares will bring in a great deal of knowledge from previous research done into the reliability and stability of Dutch water barriers.

Climate change

The stability of our railway embankments will also be affected by climate change over the years ahead. Severe weather events with extreme flooding, such as the recent flooding in Limburg are current examples of this. The challenge for ProRail is to acquire greater knowledge about the impact and effects of these factors. In this way, we will be able to ascertain better where we face risks over the years ahead, and where suitable measures are needed to facilitate the predicted rise in mobility with at the same time a rail service that is climate-proof.

From research to application

TU Delft has a great deal of knowledge on the impact of rail joints and ballast on the track and the immediate substrate, with the result that the entire system of track load and substrate can be analysed. Deltares specialises in applied research in the field of water and the subsurface.

The institute will assist in translating the results of the scientific research and the TU Delft models into practical applications, bringing in expertise in the field of dike safety, along with its experimental and digital facilities. In this way, knowledge will be built up on the effect of water on railway embankments, the effect of dry periods and the way in which a moving train imposes stresses on the embankment.

Read the complete interview with Rolf Dollevoet, Professor of Railway Engineering, on the RESET social research programme.