This issue of the CGSE e-Newsletter announces a number of additions to the Centre’s growing list of achievements. These include recent successes with respect to capturing competitive grants, key recognitions for our staff and students through prominent awards and honours, and testimonials from industry on the impacts of our research. The newsletter also includes links to information on the Energy and Transport Infrastructure Workshop, to be held at the Wollongong Node on 19 November, and a PhD scholarship available in the Centre. The last segment in this issue forms part of an ongoing series which showcases Centre activities by featuring selected projects. A major focus for the Centre at present is preparation for the mid-term review. This will occur in October this year, when an external ARC review panel will conduct a site visit and interview various Centre members. The mid-term review is an important milestone for the Centre, with continued funding dependent upon a successful outcome. The result will be announced at the end of 2014, and we look forward to receiving a positive and constructive appraisal from the panel.
Shanyong Wang was awarded $761,579 from the ARC for a Future Fellowship for a project investigating the fundamentals of fracture-controlled compensation grouting in soils. The project aims to minimise ground movements induced by underground excavations, which pose a major threat to infrastructure and communities worldwide. Small-scale laboratory experiments, centrifuge tests and numerical analyses will be conducted to develop an effective and economical grouting method, thereby providing engineers with a valuable design tool. For further information, please visit the Future Fellowships (Funding Outcomes) page.
In the latest round for ARC Linkage Projects, a CGSE team, led by Professor Buddhima Indraratna, received $735,000 from the ARC and an additional $450,000 from various industry partners to construct an embankment with vacuum pressure at the National Soft Soil Field Testing Facility (NFTF) at Ballina, NSW. The study at the NTFT will feature both standard prefabricated vertical drains and biodegradable jute drains. The project will enhance our understanding of the mechanics of vacuum-based soil stabilisation when used with vertical drains, thus contributing to Australia’s commercial advantage in adopting reliable vacuum consolidation systems. Achieving best practice and design methods with these systems will play an important role in developing cost-effective transport infrastructure on Australia’s soft coastal soils. The contributing industry partners on this grant were the National Jute Board of India, Coffey Geotechnics, Douglas Partners, Menard-Bachy, and Soilwicks Australia. The research team comprises Buddhima Indraratna (team leader, Wollongong), Scott Sloan (Newcastle), Cholachat Rujikiatkamjorn (Wollongong), John Carter (Newcastle), and David Potts (Imperial College, University of London), supported by the industry collaborators Richard Kelly (Coffey Geotechnics), Tapobrata Sanyal (National Jute Board), Geoffrey McIntosh (Douglas Partners), Philippe Vincent (Menard-Bachy), and Mr Greg Ryan (Soilwicks).
Shazzad Hossain, Mark Cassidy, and Yuxia Hu were awarded an ARC Linkage Projects grant for the project “Investigation of alternative footing shapes to mitigate instabilities during installation of offshore drilling platforms.” The CGSE researchers will partner with Jonghwa Won, Jong-Sik Park and Seong-Jong Kim from the Daewoo Shipbuilding and Marine Engineering Co. Ltd., Korea. The project will develop new spudcan shapes that are better suited to eliminate risk of failure during the installation of mobile drilling rigs (jack-ups) in emerging oil and gas frontiers of Australia and around the world. Innovation through physical and numerical modelling will ensure world leading training for one Postdoctoral Fellow and two PhD students. The research will assist in unlocking Australia’s stranded oil and gas reserves, particularly as the industry moves towards more complex seabed conditions.
Anna Giacomini and Klaus Thoeni were awarded $259,590 from the Australian Coal Association Research Program (ACARP) for the project “Rockfall hazard matrix for risk reduction in mine sites.” The project intends to develop a set of tools for rock fall hazard management in open pit mines based on field observations, mitigation measures, established analytical and numerical tools, and the latest research developments in rock fall hazard assessment and zoning. Among other expected outcomes for industry, the project will develop a methodology for generating and updating hazard zoning maps and the means to produce site specific matrices of mitigating measures. These results will provide greater confidence in locating personnel, machinery, and structures over working areas, which will improve safety as well as reduce the risk of possible interruptions in production. The project commenced on 1 April 2014 and has an anticipated duration of 2 years.
Buddhima Indraratna recently received the Medal of the Eurasian National University. The award was presented by a senior representative of the Eurasian National University, Professor Askar Zhusupbekov, Vice-President of the International Society of Soil Mechanics and Geotechnical Engineering, at the recent International Conference on Ground Improvement and Ground Control (ICGI-2012) held at the University of Wollongong. Professor Indraratna was awarded the medal for making a significant international impact through his contributions to ground improvement and transport geotechnology. The medal has been previously awarded to individuals from various backgrounds, including artists and political leaders, and Professor Indraratna is the second civil engineer to receive the honour.
Buddhima Indraratna presented the opening plenary keynote lecture at the 2nd International conference of Rail Technology: Railways 2014 in Corsica, France. This important rail conference is usually held in Europe and attracts many engineers from universities, railway industry and research organizations around the globe. Professor Indraratna’s lecture was entitled ‘Modernization of rail tracks for higher speeds and greater freight’ and will be published in the International Journal of Railway Technology. The lecture was attended by several hundreds of delegates and was well received. During the lecture, Professor Indraratna acknowledged the CRC for Rail Innovation for the research opportunities and funding, and also the Australian Research Council for the long-term support. Sanjay Nimbalkar, a CGSE researcher who attended the conference, described the address as “one of the best lectures I have heard from Professor Indraratna.” He further noted that “our PhD students’ work was also well reflected.”
Mark Cassidy, Mark Randolph, and former PhD student Kok Kuen Lee were recently awarded the Institution of Civil Engineers (ICE) Publication Award – Offshore for the paper entitled “Bearing capacity on sand overlying clay soils: experimental and finite-element investigation of potential punch-through failure,” published in 2013 in Geotechnique (Vol. 63, No. 15, 1271-1285). The ICE Best Publication Awards are awarded annually during an awards ceremony held in London, and they acknowledge works of exceptional quality and benefit to the civil engineering and science community, as judged by peers. As part of ICE’s commitment to furthering knowledge and best practice in civil engineering, the papers are free to view from their website at http://www.icevirtuallibrary.com/info/awards2014, where further information about the awards also can be found.
Hassan Sabetamal, a PhD student in the CGSE, won the prestigious Australian Geomechanics Society NSW Research Award for research in Geotechnical Engineering or Engineering Geology. This award recognises novelty, originality, and industry relevance and was given for his work on finite element algorithms for dynamic analysis of geotechnical problems. Hassan’s research describes new computational methods for the analysis and design of a wide range of energy and transport infrastructure, such as building foundations, bridge foundations, offshore oil and gas facilities, retaining walls, slopes and tunnels. Dynamic loads occur frequently in practice, particularly under earthquake conditions, and are difficult to model using conventional techniques. Hassan has also worked on the modelling the complex behaviour that occurs at soil-structure interfaces under dynamic loading. He is supervised by Majid Nazem, Scott Sloan, and John Carter.
Rasika Athukorala, a former PhD student who now works as a post-doctoral researcher in the Research Centre for Geotechnical and Railway Engineering (GRE), was selected as a finalist for the Australian Geomechanics Society NSW Research Award. The judging panel initially screens the written submissions from PhD students from various NSW universities based on technical content, originality, industry relevance, and written clarity, and the panel then short-lists the top three candidates. The final assessment is made based on oral presentations held in Sydney and Newcastle, sponsored by the local chapters of the Australian Geomechanics Society. Rasika’s research focussed on the study of erosion behaviour of lignosulfonate treated soil. Her research was conducted under the supervision of Buddhima Indraratna and J. S. Vinod as part of a project funded by an ARC Linkage grant.
PhD student S. M. Ali Tasalloti from the Research Centre for Geotechnical and Railway Engineering (GRE) won the 2014 Young Professionals Geotechnical Competition. The competition, held in Sydney, was hosted by the Australian Geomechanics Society and the Institution of Engineers Australia. Ali’s research pertains to the development of a suitable reclamation fill for Port Kembla Outer Harbour extension, since the conventionally dredged marine soils were found to be environmentally and geotechnically unacceptable. The project investigates the potential for using blended steel furnace slag and coal wash as a substitute for conventional natural fills for offshore reclamation. Ali gave his presentation to a full auditorium and faced stiff competition, with excellent presentations from several young professionals from academia and industry. The judging panel considered the quality of both written papers (published in the Australian Geomechanics Journal) and the oral presentations in selecting the overall winner. This is the fourth time that a PhD student in geotechnical engineering at the University of Wollongong has won this competition since its inception about a decade ago. Ali is supervised by Buddhima Indraratna, Ana Heitor, and Cholachat Rujikiatkamjorn, and his work represents part of an ARC Linkage Project supported by Port Kembla Port Corporation, Douglas Partners, Coffey Geotechnics, Menard Bachy, BHP Billiton and ASMS.
The CGSE is offering a PhD scholarship to study the mechanisms governing laboratory and in situ testing in soft natural clays. The multifaceted research project will involve an intriguing blend of laboratory testing using high-quality undisturbed samples recovered from the Centre’s National Soft Soil Test Facility at Ballina, NSW, and advanced numerical simulation of soil tests allowing for very large deformations. The project crosses two of the Centre’s four research themes, falling within the themes of Geomaterials Science and Moving Boundary Problems. Its focus will be on the development of novel testing procedures, together with the modelling of strain softening and rate effects on the shear strength of clays in large deformation boundary value problems. Suitable candidates will have a background in civil engineering, preferably with a master’s degree in geomechanics or computational mechanics. Candidates should have relevant experience in computer programming and/or laboratory testing. The scholarship stipend will depend on the merit of the candidate, and will be in the range of AUD 30,000 – 35,000 p.a. (tax free) for three years. Please submit expressions of interest along with a copy of your CV to Dr George Kouretzis. Email George for further information. The closing date for applications is 31 August 2014. The scholarship is available to commence immediately.
The Centre for Geomechanics and Railway Engineering through the CGSE will be organising the Workshop on Transport and Energy Infrastructure: Research and Practice at Wollongong (Australia). The workshop will be aimed at promoting transport and energy infrastructure concepts and geotechnical applications in practice and will be held on 19 November 2014 at Wollongong. (Download Workshop Flyer) (Register for the Workshop)
An innovative offshore anchor designed by CGSE researchers at The University of Western Australia has already been snapped up by Dutch anchor specialists Vryhof Anchors. The Dynamically Embedded Plate Anchor (DEPLA) was developed by Associate Professor Conleth O’Loughlin, from UWA’s Centre for Offshore Foundation Systems (COFS), and Dr Mark Richardson, a former PhD student at COFS. The new anchor design, aimed at mobile drilling units and floating production systems in deep and ultra-deep water, would reduce installation time, costs and materials, Associate Professor O’Loughlin said.
Associate Professor O’Loughlin, who has been researching dynamically installed anchors for the past 10 years, said the anchor was a hybrid system able to sustain significant vertical load and required no external energy source or mechanical operation for installation. “The anchor resembles a dart, and is installed using gravity, similar to other dynamically installed anchors such as the torpedo pile,” he said. “However the main part of the ‘dart’, which we call the follower, is removed after the anchor is embedded in the seabed and re-used for the next installation. This leaves the anchor flukes in the seabed, which then become the plate anchor.” Associate Professor O’Loughlin said global energy company Petrobras had been using a gravity-embedded design since the mid-1990s. “But the rest of the world has been slow to follow,” he said. “However, one of the limitations of the Petrobras design is that it is not the most efficient – it doesn’t have a lot of capacity relative to its weight. “The DEPLA boasts all the installation advantages of the torpedo pile, but is much more efficient at resisting load, meaning that much smaller and cheaper units can be used for mooring offshore facilities. Being able to re-use the follower is a significant bonus.”
Vryhof project director Senol Ozmutlu said results indicated the DEPLA exhibited similar behaviour to other dynamically installed anchors during installation, but with much higher capacities and predictability than other dynamically installed anchors that resisted load in friction. The DEPLA has been tested at model scale in the geotechnical centrifuge facilities at COFS. In these experiments, soil samples are spun at up to 200 times Earth’s gravity, creating stress conditions in the centrifuge sample that are equivalent to tens of metres of the seabed. The DEPLA was put through its paces in these tests, with the centrifuge data playing a pivotal role in informing the final design concept. This is now a well-accepted approach for obtaining performance data of geotechnical systems and COFS is a world leader, with both beam and drum centrifuge facilities that are heavily utilised by the offshore industry worldwide. Vryhof’s Business Development Director Leo Bello said the company was extremely happy with the new anchor. “It will give us a reliable product for ultra-deep water uses that will help our clients reduce their overall mooring cost,” Mr Bello said. “The DEPLA combines the advantages of dynamically installed anchors and vertically loaded anchors and is fully patented.” The DEPLA has been extensively tested at a quarter scale and it will be now Vryhof ‘s task to engineer and test a full-scale prototype. “Vryhof was the ideal industry partner to continue development of the DEPLA and we look forward to assisting them in making it a real prospect for the offshore industry” Associate Professor O’Loughlin said.
Buried pipeline networks are quite literally the circulatory lifelines of modern society, bringing water from catchment areas and gas from offshore basins to our houses, and carrying our waste to treatment facilities. Despite billions of dollars spent on pipeline infrastructure, stringent design codes, and continuing emphasis on safety, things can still go wrong. Catastrophic failures such as the explosions of the gas pipeline in Texas, USA in 2010, the oil pipeline in Qingdao, China in 2013, and the natural gas pipeline in Manitoba, Canada in January 2014 have resulted in loss of life, contamination of the environment due to the uncontrolled release of oil and gas, and disruption of services to hundreds of thousands of people. And they happen more often than you might realise. Over ten thousand serious incidents in onshore pipeline systems transporting hazardous liquids and gas were reported between 1993 and 2004 in the US alone, resulting in 368 fatalities and property damage of around USD $5.5 billion. Pipeline failures need not be catastrophic to have enormous environmental and economic impact. Researchers from Monash University and CSIRO Land and Water have documented 39,687 failures in Australian water distribution networks over a 10-year period. The average cost of service disruptions and repairs to the cast iron water pipelines in Western Australia alone has been estimated at AUD$450/km each year, with 43 billion litres of drinking water lost each year. This amounts to 12% of the water supplied in Western Australia, mainly through leaky pipes. Clearly, work still needs to be done – to make the pressurised mega-pipelines of the future safer, to minimise the small and insidious (but cumulative) leaks, and to safely reduce the construction and maintenance costs of our ever-expanding pipeline networks.
George Kouretzis and his team in the CGSE are focusing their research on optimising pipeline designs to minimise risk and reduce costs. As practising engineers with design experience on large Australian and international projects, they have seen first-hand how limitations in the current pipeline design codes and methodologies can confound best-practice design. “We were originally working on the design of a feed gas pipeline through a region of high seismicity in Europe, and realised that the existing design guidelines developed in the 1970s weren’t sufficient to cover these special conditions,” explains Dr Kouretzis. “We used a combination of numerical work and field data to develop a new methodology that was more robust and suitable to the extreme conditions.” They then extended their research to make their methodology generally applicable to areas of high seismicity, and developed straightforward analytical solutions to make their findings directly useful for practising engineers. A combination of their prominent research profile, publishing success and good connections with industry bodies has seen their design revisions incorporated into the last update of the US pipeline design codes. “It’s all about bridging the gap between research, engineering applications and public benefit,” says Dr Kouretzis. “The engineer in the field doesn’t have time to read academic journals and go to international conferences, so it’s important that we develop our research to the point where we can create straightforward analytical methods for design problems that can be solved within a simple spreadsheet, and then get them into the regularly-revised design codes that practising engineers are using.” The team has more recently been working on problems more relevant to Australian conditions. The number of mine sites and refineries in Australia, in combination with the length of our gas pipelines, means that designing the safe distance between a pipeline and a potential blast hazard is a relatively common occurrence. Unfortunately the current design methods date back to a specific set of physical experiments, carried out to work out how far away to put a gas pipeline from a particular mine site. Dr Kouretzis’ team have worked to expand the methods from a very specific set of conditions to be more broadly relevant to different pipeline types and soil conditions. This work on blast-induced strain in pipelines is already published and highly cited, and has been used on some high-profile international design projects. The team is hopeful it will be incorporated in the next revision of the US pipeline design codes.
Another area of increasing concern in Australia is designing pipelines in areas of reactive soil deposits, where the terrain’s engineering behaviour varies with environmental factors. These soils are very common across Australia, and emerging data shows that pipeline failure rates in distributed networks, such as metropolitan water networks, are significantly higher in wet seasons, which are associated with increased soil moisture content. The team is now refining guidelines for pipelines in these regions to account for changes in soil behaviour with climate change, effectively designing a more robust network for these areas. A long-standing argument between engineers and contractors concerns the best way to dimension a trench for buried pipelines. Although the trench should be sized to avoid interactions between the pipeline and the natural soil, estimates are based on limited trench configurations, and there are no robust design guidelines. Without a rigorous methodology, the ‘choose the minimum dimensions, save on excavation costs’ conversation happens regularly. Dr Kouretzis’ team is now developing design charts to determine the minimum trench dimensions that will prevent interaction of the pipeline with the surrounding natural soil, so that the pipeline response to external loads will depend solely on the properties of the controlled backfill material and not the surrounding soil. Their results suggest that the geometry of the trench must be carefully determined to control interaction effects while minimising construction costs, a working outcome sure to be of interest to many design engineers. By developing ready-to-use software tools for testing pipeline scenarios, these researchers are bridging the gap between research and engineering practice, and minimising the time required for new developments to make their way into everyday pipeline projects. Dr Kouretzis notes, “this work belongs in the field, with the pipeline engineers who select appropriate materials for pipeline strength, decide on welding techniques and trench dimensions, quantify the risk associated with natural geological and climactic processes, and design mitigating measures in areas of unacceptable risk.”