Advances in Transport Geotechnics – Soil Fluidisation and Track Instability, Net-zero and Circular Economy Perspectives
Chandrakant Desai Memorial Webinar Series
Distinguished Professor Buddhima Indraratna
Ballasted tracks are commonly used for passenger and freight transportation because of several reasons, including economic considerations, load bearing capacity, rapid drainage and ease of maintenance. During track operations, ballast progressively deteriorates and the infiltration of fluidized fines (mud pumping) from the underlying substructure decreases its shear strength and impedes drainage, while increasing track deformation and associated maintenance. The primary focus of track upgrades should be the incorporation of sustainable materials aligned with circular economy principles, which will not only enhance track performance but also contribute to achieving net-zero goals. The inclusion of recycled rubber, and mining waste mixtures as alternatives to conventional materials requires a deeper understanding of their performance under repeated dynamic loading. In this presentation, these aspects are examined through fully instrumented case studies and large-scale 1:1 physical modelling, complemented by advanced constitutive modeling and computational analyses to better understand the underlying mechanisms and soil–structure interaction. Based on track innovations with associated patents, the application of recycled rubber tyre assemblies infilled with waste materials as an energy absorbing foundation, as well as the use of impact-damping rubber mats and grids made from recycled conveyor belts to reduce track degradation will be demonstrated through Australian case histories. Compared to standard railways, rubber inclusions significantly reduce stress transfer to the subgrade while retaining strain energy during the passage of trains, thereby limiting excessive deformation in the longer term, despite initial settlement. These results indicate that the use of recycled material reduces the chances of subgrade failure and it can be a sustainable solution in areas with weak subgrade soils.
Distinguished Professor Buddhima Indraratna Professor, Director of Transport Research Centre, Faculty of Engineering and Information Technology, University of Technology Sydney
Buddhima Indraratna, a Member of the Order of Australia, is a Distinguished Professor of Civil Engineering, and Director of Transport Research Centre, at the University of Technology Sydney (UTS). He graduated in Civil Engineering from Imperial College, London, and obtained his PhD from the University of Alberta in 1987, after several years in industry. He received the esteem honor as the 6th International Civil Engineer Award in Madrid, hosted by Jose E. Iberra Foundation and the Technical University of Madrid, and Sir John Holland Civil Engineer of the Year 2024 awarded by Engineers Australia. Other notable accolades include ISSMGE’s 1st Ralph Proctor and 4th Louis Menard Lectures, and the EH Davis Lecture of AGS. He has successfully supervised 130+ research students (~85 PhD) and over 45 Postdoctoral Fellows. He has produced over 1000 publications (14 Books; 530+ Q1 journal articles), and amongst the most highly cited civil engineers (h-Index=100). He has been a geotechnical consultant and a former UN expert. He is a Fellow of the Australian Academy of Technological Sciences and Engineering and a life member of the Australian Geomechanics Society (AGS).
This International Association for Computer Methods and Advances in Geomechanics event is co-hosted by the Australian Geomechanics Society.
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