Atalan, Mucahit
(2025)
The dynamics of slab track railway systems.
PhD thesis, University of Nottingham.
Abstract
The dynamics of slab track railway systems have garnered significant attention due to the increasing speed and axle loads of modern trains. This thesis addresses the critical issue of track structure performance under high-speed and different site conditions. Traditional track structures, primarily developed for lower speeds and lighter loads, often fail to adequately handle the dynamic stresses imposed by modern trains, leading to increased maintenance costs and potential operational inefficiencies. This research investigates innovative solutions to mitigate these challenges, focusing on the integration of structural asphalt layers within slab track systems.
The aim of this research is to develop a 3D numerical model to optimise the design of high-speed slab track systems, particularly those incorporating structural asphalt layers. This study seeks to address several key gaps in the existing literature: the limited understanding of dynamic effects on high-speed railway lines in slab-asphalt track systems, the optimal use of asphalt materials specifically for railway applications, and the need for a 3D finite element model to accurately simulate complex interactions between train, track, and soil. The model serves as a tool to investigate the performance of different slab track designs under various dynamic loading conditions and track defects. Beyond the model development, the research includes detailed analyses of the dynamic response of slab track systems, exploration of debonding behaviours, and comparative studies of different track designs.
The research methodology begins with a literature review, providing a foundation for the subsequent stages of the study. This review covers the historical development of railway infrastructure, focusing on the transition from traditional ballasted tracks to modern slab track systems. It examines the mechanisms of vibration and wave propagation in track systems, with particular attention to critical speed and resonance effects associated with high-speed trains. The review also analyses various analytical and numerical modelling approaches previously employed in railway dynamics studies. This thorough examination of current knowledge reveals the understanding of slab-asphalt track systems, particularly their dynamic behaviour under high-speed conditions. It also highlights the need for more sophisticated modelling techniques that can accurately capture complex train-track-soil interactions.
To address the identified research gaps, this study develops and applies a sophisticated three-dimensional finite element model using ABAQUS software. This model is designed to simulate the dynamic behaviour of slab track systems under high-speed conditions, with a particular focus on systems incorporating structural asphalt layers. The model integrates key elements such as contact behaviour, moving load dynamics, and rail defect modelling to accurately represent real-world conditions. It is validated against existing case studies, ensuring its reliability and accuracy. The research also involves examining various scenarios, including different soil stiffness conditions, to understand their impact on track performance. This approach allows for an analysis of how soil properties affect the dynamic responses of slab track systems. By applying this model to various soil scenarios, including the investigation of debonding effects and local track irregularities, the study provides new insights into the behaviour of slab-asphalt track systems under high-speed conditions. This approach enables the research to address the identified gaps in current knowledge and contribute to the optimisation of high-speed railway infrastructure design.
One of the key findings of this research is the significant impact of train-induced ground vibrations on slab track systems. The results show that integrating an asphalt layer within the track structure enhances its dynamic performance, increasing bearing capacity and stiffness, and thereby reducing stress and deformation under high-speed loads. For instance, the study reveals that a hybrid track design, which combines asphalt and cement-based materials, reduces peak vertical displacement by 15% and stress levels by 20% compared to traditional slab track systems. The thesis further investigates the effects of local track irregularity on track displacement, stress levels, and peak particle velocity. The results highlight the importance of maintaining uniform track geometry to minimise dynamic effects and ensure the safety and stability of high-speed rail operations.
This thesis has demonstrated the significant benefits of integrating structural asphalt layers into slab track railway systems under high-speed conditions. By developing a sophisticated 3D numerical model using ABAQUS, the study provides a detailed analysis of dynamic responses, including the effects of debonding behaviours and track irregularities. Key findings show that asphalt layers enhance track performance by increasing bearing capacity and stiffness, and reducing stress and deformation. The hybrid track design, combining asphalt and cement-based materials, effectively mitigates peak vertical displacement and stress levels. These insights offer practical recommendations for optimising high-speed railway infrastructure, paving the way for more efficient and durable rail networks.
| Item Type: |
Thesis (University of Nottingham only)
(PhD)
|
| Supervisors: |
Thom, Nick
Prendergast, Luke |
| Keywords: |
Slab track systems, High-speed railway, Dynamic behaviour, 3D finite element modelling, ABAQUS, Debonding behaviour, Track irregularities |
| Subjects: |
T Technology > TF Railroad engineering and operation |
| Faculties/Schools: |
UK Campuses > Faculty of Engineering
UK Campuses > Faculty of Engineering > Department of Civil Engineering |
| Item ID: |
81728 |
| Depositing User: |
Atalan, Mucahit
|
| Date Deposited: |
31 Dec 2025 04:40 |
| Last Modified: |
31 Dec 2025 04:40 |
| URI: |
https://eprints.nottingham.ac.uk/id/eprint/81728 |
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