Keynotes

Topic: Geosynthetics in South Africa: 40 Years of Lessons Shaping a Sustainable Future

The keynote will cover Garth’s career spanning four decades from the pioneering of geosynthetics in South Africa to the present day, with a focus on water containment dams and tailings storage facilities. Garth will reflect on South Africa as a proud and innovative nation highlighting the significant achievements in geosynthetics and how these efforts have earned international recognition and respect within the industry.  Credit will be given to the pioneers and trailblazers whose vision, expertise, and commitment laid the foundation for the industry as it exists today. The presentation will include details on the use of recycled polymer in the manufacture of world class products, the establishment of geosynthetic clay liners (GCLs) in the lining industry, and local production using quality raw materials and technology. Finally, the keynote will provide a critical reflection on resistance to change in certain aspects of the industry in certain areas of application as well as over-conservative or, at times, poor designs. The presentation will conclude with commentary on ensuring proper installation through adherence to tried-and-tested methodologies—an essential factor in achieving long-term performance and sustainability.

After graduation Garth practiced as an Engineering Geologist for over 10 years before joining Kaytech, a manufacturer and supplier of geosynthetics, in 1985, where he enjoyed 34 active years in the Geosynthetics industry before he retired in June 2019 as their Technical Director. He authored and presented technical papers on Geosynthetics at regional and international conferences where he also assisted as a referee and session chair.

Garth served as President of GIGSA, the local Chapter of the IGS. During his second term GIGSA hosted the 1st African Regional Conference of the IGS in Cape Town in September 2009.

He Co-chaired the Technical Committee for the Second African Regional Conference in Accra, Ghana, in November 2013.

He lectured post graduate courses at university on the design and application of Geosynthetics.

He holds the following memberships:

• SA Institute of Engineering Geologists
• SA Institution of Civil Engineering
• Honorary Life Membership of GIGSA
• International Geosynthetic Society
• Institute of Waste Management of SA
• Society for Asphalt Technology
• Technical committee for the National Technical Guidelines on Asphalt and Base Reinforcement for Road Construction.

Garth currently consults to the industry as a specialist geosynthetics and geotechnical practitioner.

Topic: Sustainable bridge construction with geosynthetics: the proof is in the numbers!

Permanent reinforced soil structures have become established as reliable alternatives to conventional mass and cantilever earth-retaining structures since the early 1980s. Similarly, temporary earthworks structures, like working platforms, have also evolved from thick unbound aggregate platforms to lean, cost, time and carbon effective aggregate platforms when stabilised with geosynthetics. The use of geosynthetics and in particular the use of geogrids, opened up possibilities for the construction of extraordinary retaining structures that would not otherwise be feasible or would be overly expensive, such as the construction of reinforced soil retaining structures in excess of 60 m in height or the construction of load-bearing bridge abutments on shallow foundations over challenging soil formations and without the need for deep piling foundations. At the same time, the use of geogrids has turned waste into resource by enabling the re-use of sub-standard, recycled fill, like construction and demolition waste in temporary and permanent works construction, such as working platforms, haul roads and permanent highways, paving the way to reliable, longer-lasting, sustainable infrastructure and promoting circular economy.

This keynote will start with a brief historic introduction of the origin of polymer geogrids, our evolution in understanding their performance, our efforts in convincing our industry to accepting geogrids as forming reliable construction solutions even for high-risk infrastructure like bridge abutments, and through real-world case studies, it will demonstrate up to 85% carbon savings when using geogrid stabilised soil solutions versus ‘traditional’ construction methods in bridge construction.

Yuli is the Chief Civil Engineer for Tensar, a Division of CMC, which is globally renowned for inventing polymeric soil reinforcing and stabilising geogrids. Yuli started her career in geotechnics working as a graduate tunnel engineer at the Jubilee Line Extension, Contact 102 in London. She then moved to Hong Kong. After ten years working in Hong Kong as a geotechnical engineer specialising is slope stability and retaining structures, she returned to the UK and joined Tensar, maintaining overall responsibility of their Eastern Hemisphere Design Team for more than 10 years. More recently, whilst still involved in delivering training, project risk management and high-level advice on scheme feasibility studies, she has diverted her focus largely towards Business Development and educating the industry globally on the benefits of geosynthetics in construction.

Yuli is a Chartered Engineer (CEng), a Fellow of the Institution of Civil Engineers (FICE), a Fellow of the Railway Engineering Institution (FRailEI), a Member of the Hong Kong Institution of Engineers (MHKIE), and the first non-military engineer to become a Fellow of the Institution of Royal Engineers (FInstRE) in May 2018. Yuli has served as a past Chair of the UK Chapter of the International Geosynthetics Society (IGS) and she is the current Chair of the British Geotechnical Association (BGA). Yuli is actively involved in many national and international engineering panels and has authored, co-authored and presented several publications about practical applications of reinforced and stabilised soil systems around the world.

Topic: How long will my geomembrane last? A guide to material selection and service life in mining applications.

Geomembrane liners are critical components of barrier systems used in mining applications, supporting environmental protection while facilitating efficient metal recovery. Heap leach pads, tailings storage facilities, and waste-rock containment systems expose geomembranes to markedly different chemical, thermal, mechanical, and operational conditions that can significantly affect their long-term performance. The geomembrane type and formulation must therefore be carefully selected to suit the anticipated exposure conditions and required design life. Polyethylene geomembranes are the most widely used liners in mining and include high-density polyethylene, linear low-density polyethylene, blended polyolefin, and bimodal polyethylene products. Bituminous geomembranes have also gained increasing acceptance, with millions of square metres installed worldwide. A key question remains: does the selected geomembrane have the appropriate formulation and durability to achieve the required service life under site-specific conditions?

This keynote lecture will present long-term immersion data demonstrating how mining-solution chemistry, geomembrane formulation, and exposure temperature influence the ageing and performance of different polyethylene geomembranes. Results from studies extending beyond seven years will also be presented for bituminous geomembranes, providing insight into their degradation mechanisms and chemical compatibility with aggressive mining solutions. The lecture will conclude with key lessons for evaluating geomembrane durability and selecting suitable liner materials for harsh mining environments.

Fady is an Associate Professor in the Department of Civil Engineering at Queen’s University, Kingston, Canada and a Research Director at the GeoEngineering Centre at Queen’s-RMC. His 18-year research expertise involves polymeric and bituminous geosynthetic barrier systems for geoenvironmental applications, with a focus on understanding their long-term degradation behaviour. Dr. Abdelaal currently serves as a Council member and Educational Committee Chair of the International Geosynthetics Society (IGS), President Elect–IGS North America, and the Academic support for the delivery of projects,IGSTechnical Committee barriers (IGS-TC B). He was the immediate past Chair of the Geosynthetic Division of the Canadian Geotechnical Society (CGS). He also serves on the editorial boards of Environmental Geotechnics, Geosynthetics International, and Frontiers for Built Environment Journals, as well as an Associate Editor for the Geotextiles and Geomembranes Journal.