Fatigue and U-frame assessment of metallic railway bridges
Start date
March 2020End date
March 2024Overview
The majority of metallic railway bridges in UK, approximately 10,000 in total, are already exceeding 100 years of age and are approaching the end of their theoretical service life. Replacement of these structures will be extremely expensive and practically impossible unless phased-in over several decades. Therefore, in many cases, rehabilitation and repair options need to be further developed, since they will be more economic and compatible with available resources. However, even this course of action is likely to create severe logistical problems on the railway network, if deemed necessary on a large scale. The principal objective of this project, i.e. better understanding, modelling and prediction of a bridge’s fatigue and U-frame performance, will lead to a more effective use of limited and stretched resources and can reduce the rate of rehabilitation/repair or unwarranted early replacement, thus keeping the railway network operating for longer periods without unnecessary disturbances.
The project reviews critically existing fatigue and U-frame assessment methods used by Network Rail to identify their limitations and inherent uncertainties arising due to the non-standardised designs that were used during construction in the late 19th and early 20th centuries. The project specifically focuses on a better understanding of fatigue in the context of specific materials and assembly methods used in railway bridges, followed by development of modelling techniques that can lead to more accurate prediction of a bridge’s fatigue performance. A major part of the project involves execution of an experimental programme, consisting of small-scale and full-scale static and fatigue tests of materials/components extracted from a disassembled old metallic railway bridge provided by Network Rail, which will be used to benchmark and verify analytical/numerical methods and models and assess their predictive capability and accuracy. The outcomes of this applied research will feed into the standardisation and dissemination of these issues and their integration within existing rules.
Funding amount
£565,000
Funder
Network Rail
Team
Principal investigator
Dr Boulent Imam
Associate Professor (Reader) in Civil Engineering
Biography
Dr Boulent Imam graduated with an Honours BSc degree from the Middle East Technical University in Ankara, Turkey. He obtained his MSc in Structural Engineering with Distinction from the University of Surrey in 2002. His MSc dissertation was on the probabilistic fracture assessment of the Northridge moment resisting connections and led to the publication of two papers. Dr Imam continued his studies at the same university where he successfully defended his PhD in June 2006. Dr Imam's PhD work focused on the fatigue analysis of riveted railway bridges and was funded by EPSRC and Network Rail. He developed a general methodology for the fatigue assessment of riveted railway bridges, through finite element (FE) analysis, by concentrating on the fatigue behaviour of railbearer-to-cross-girder connections. Following his PhD, Dr Imam continued his research as a postdoctoral researcher at the University of Surrey expanding his experience in load modelling by investigating the effect of future railway loading evolution scenarios on the remaining life of riveted railway bridges. Parallel to this study, he also investigated, as a continuation of his PhD work, the application of novel assessment methods (Theory of Critical Distances) for more reliable remaining fatigue life estimation of riveted bridge connections.
In November 2007, Dr Imam was appointed as a Lecturer in Civil Engineering at the Faculty of Engineering and Physical Sciences in the University of Surrey. He was promoted to Senior Lecturer in 2013 and to Associate Professor (Reader) in 2022. His expertise spans asset management, structural assessment, load modelling, and the risk and reliability assessment of transport infrastructure, with a particular focus on the performance and maintenance of bridges under varying environmental and operational conditions.
Dr Imam is the founding director of the MSc programme in Infrastructure Engineering and Management which specialises postgraduate students on system-of-systems approach for the planning, delivery, operation and decommissioning of infrastructure systems. He has also been the MSc programmes coordinator of multiple MSc programmes at University of Surrey, including the only postgraduate programme in Bridge Engineering in Europe (MSc Bridge Engineering). He has led internal validation and external accreditations of MSc programmes as has acted as the Distance-Learning manager of our online MSc programmes in the past. He is currently external examiner for MSc programmes in two UK Universities.
Dr Imam has been actively disseminating his research contributions in major international and national conferences, including invited Keynote Lectures, growing his international reputation in infrastructure asset management. He has been member of the scientific committee of major international conferences and has organised a number of special sessions. He is in the Editorial Board of high-profile journals and has been active reviewer for a wide range of journals. Dr Imam has successfully supervised over 20 PhD students and post-doctoral researchers and has been invited as external examiner for PhD vivas across the world.
Co-investigator
Project images
