Challenges of Railway Embankments Remediation

In the absence of proper maintenance efforts, the railway infrastructure ageing process leads to generally poor network conditions. In common with many rail networks, there is a wish to increase capacity on the network while in same time infrastructure managers are dealing with the effects of climate change which can result in catastrophic failures. These climate impacts are most prominent on railway earthworks, especially earth embankments. Longer duration and more intense precipitation events result in number of embankment failures, including soil stability issues, excessive settlements of embankments, etc. All this significantly affects both safety and functionality of railway networks. Continuously increasing axle loads, along with poor drainage conditions and unfavourable geometry of these embankments, where their side slopes tend to be much steeper than modern highway slopes made in similar soils, make them extremely prone to failures. This paper presents several case studies of railway embankment failures occurred on Croatian railway lines, along with challenges that arose during the asset condition assessment, remediation design and remediation works. An insight into remediation contingences due to the specific nature of railway infrastructure is also given, encompassing different engineering aspects.