STATIC AND SEISMIC PERFORMANCE OF GEOSYNTHETICS IN CIVIL ENGINEERING – Monday 18th February 2019 – Auckland
The Australasian Chapter of the International Geosynthetics Society recently hosted their International Speakers Series in Australia and New Zealand.
The New Zealand seminar was held in Auckland and presented by Professor Timothy Stark, Professor of Geotechnical Engineering in the Department of Civil and Environmental Engineering at the University of Illinois at Urbana–Champaign. Important lessons were learned by the 40 delegates attending the seminar about current best practice use of geosynthetics for embankment and lined waste containment facilities based on current research and from analysis of real life case studies of failures.
Professor Stark presented on the following topics:
- Geosynthetic Interface Testing and Selection for Static and Seismic Stability where he explained the importance of interface shear testing for geosynthetic lined slopes, the correct test methods to use, and the interpretation of these test results.
- Vertical Geosynthetic Drain Analyses for Embankment Failure on Soft Soil were he presented case histories illustrating design parameters for prefabricated vertical (wick) drains and their practical implications for stability of embankments.
- Seismic Stability of a Geosynthetic Lined Slope where he presented, using a case study, the importance of designing for peak and residual shear strength on landfill liner systems base and side slopes respectively and the appropriate factors of safety to use for the design cases.
- Elevated Temperatures in Waste Containment Facilities and Effect on Geosynthetic Service Life and Facility Design where he presented on the causes and implications for geosynthetic service life of elevated temperatures in waste containment facilities.
GEOSYNTHETICS IN TRANSPORT INFRASTRUCTURE – Tuesday 19th February 2019 – Melbourne
With transport infrastructure activity reaching historically high levels in Melbourne, the topic was well received with over 35 people attending the seminar that focussed on roads, tunnels and retaining walls.
There were several highlights, including –
- Jorge Zornberg showcasing his research into roads built on expansive soils, and how the use of geogrids can control cracking. It was interesting to see how the USA road authorities approach specification of geogrids to ensure performance, especially as the different geogrids yield different performance outcomes in terms of surface cracking of the roads built on different soils.
- Chungsik Yoo spoke of his experiences with tunnels, including showing where geosynthetics are used within tunnels. Of particular interest was the role that geosynthetic drainage plays in enhancing the durability of some particular tunnel structures
- Chungsik then updated us with details on the emergence of geosynthetic reinforced bridge abutments, which are growing in use around the world as road authorities recognise the decades of engineering data supporting geosynthetic reinforcement. Later in their trip, Jorge visited one of the few Australian examples of geosynthetic reinforced bridge abutments.
- Allan Garrard (CMW Geosciences) gave a very interesting talk that reflected the modes of retaining wall failures, as well as several specific failures he has been involved with (after the event, as part of the forensic analysis) over his career in geotechnical engineering,
It was certainly an instructive talk for all who attended, as many were civil engineers involved in the major infrastructure currently underway that is reshaping Melbourne’s transport network.
GEOSYNTHETICS IN MINING – Friday 22nd February 2019 – Brisbane
The ACIGS educational week culminated in a mining seminar in Brisbane, with over 50 people in Brisbane attending to understand the use of geosynthetics in mining.
Tim Stark, Chungsik Yoo & Jorge Zornberg showed how geosynthetics can be used to solve the very specific problems faced by the mining industry, supported by practical case studies from experienced engineers.
The topics were highly relevant, including –
- mine closures, which are becoming increasingly relevant as specific assets come to the end of their life (whether it be mines or tailings dams etc). There are a range of geosynthetic solutions available to achieve a broad range of desired outcomes.
- tunnelling, which is a key part of mining activities
- a presentation on tailings dams including review of recent failures from around the world. The risk management of tailings dams are a hot topic globally, and the subsequent discussion was very lively.
Several industry participants showcased a range of Australian mining problems solved by geosynthetics, including several recent mine closure projects using relatively new systems or an innovative engineering approach. As a world leader in mining, Australia has a rich history of geosynthetics in mining applications, and that experience and expertise was very evident within the attendees at the Brisbane seminar.
The week ended as a great success, with our overseas speakers sharing their experiences to more than 120 people across four cities in five days. All the materials were provided to the attendees, and the three industry seminars will shortly be available on-line in video form.
