AGS WA Symposium 2022
Engineering Geology and Geotechnics of Western Australia
Alex Petty, John F Kennedy, Nina Levy and Barry Lehane
The Western Australia (WA) Chapter of the Australian Geomechanics Society (AGS) is pleased to announce a one-day symposium titled “Engineering Geology and Geotechnics of Western Australia” which is to be held on 17 November 2022. The event will be held in Perth, forming a part of the continued program of events organised by the AGS WA Chapter. It aims to bring together geotechnical professionals to share and discuss their knowledge and experiences related to the engineering geology and geotechnical characteristics of the ground on which we build in Western Australia.
After being in isolation from the rest of Australia and the world, Western Australia is now open and development is booming. Economical and safe geotechnical design requires a good understanding of the engineering geology and characteristics of the ground on which we build. This symposium will provide geologists and geotechnical engineers from all backgrounds with a fantastic opportunity to talk about what is currently happening in WA and what is next.
The symposium will present an overview of the geotechnical and geological conditions of the ground in WA, with some case studies.
The symposium will bring together professional engineering geologists engineers, researchers, specialist contractors, regulators, educators and students to share and discuss their experiences on the topic of Engineering Geology and Geotechnics of Western Australia. Best practices, case histories and innovative methods for assessing and characterising ground risk will be presented and discussed, with a particular emphasis on the geology of the metro region, regional areas of WA, and offshore WA.
Registrations have now closed.
08:00 – 08:30 Registration
08:30 – 08:35 Opening Address
08:35 – 10:30 Session 1
10:30 – 11:00 Morning Tea
11:00 – 12:30 Session 2
12:30 – 13:30 Lunch
13:30 – 15:00 Session 3
15:00 – 15:30 Afternoon Tea
15:30 – 17:00 Session 4
17:00 – 18:30 Cocktail Drinks
Alex Petty Geotechnical Services Lead, WA, Stantec Australia
“Why is geology important to Geotechnical Engineers? Principles, practices, and examples from across WA.”
Engineering geology is defined in the statutes of the IAEG as “the science devoted to the investigation, study and solution of engineering and environmental problems which may arise as a result of the interaction between geology and the works or activities of man, as well as of the prediction of and development of measures for the prevention or remediation of geological hazards.”
Every construction project is either impacted or impacts the natural ground surface in some way. Whether this is because of existing natural geological hazards; because foundations are placed within it; or slopes are cut into it or because construction materials are obtained from it. Geological processes have formed the natural soils and rocks found on the earth’s surface. So, it stands to reason that an understanding of the processes which formed them is important in a clear understanding of their composition and potential response to engineering interactions (loads, unloads, change in water levels, earthworks etc.).
This presentation aims to demonstrate the importance of geology in geotechnical applications. It introduces the fundamental principles of uniformitarianism and superposition (in both the engineering and geological sense) and how their application relates to geotechnical engineering.
These principles are then explored further in the context of desktop studies, geotechnical investigations, soil and rock descriptions, ground / geotechnical models, and parameter derivation, using relevant examples from WA.
Alex Petty has over 16 years professional experience working as a Geotechnical Engineer across the UK, Australia, South America and New Zealand. He is a chartered engineer with Engineers Australia (CPEng) and is also a Fellow of the Geological Society of London (FGS). Alex has worked across a wide variety of sectors primarily in the civil space and more recently across to the mining industry.
Alex has a significant level of experience in a wide range of geotechnical applications, including geological mapping, geotechnical investigations, soil and rock slope stability assessments and tailings and earthworks construction. Alex has a keen interest in progressing the geotechnical field and in mentoring and knowledge sharing.
John F Kennedy Principal Engineering Geologist 4DGeotechnics Pty Ltd
“Engineering geological input to planning, construction and operation of mine infrastructure in the Pilbara region of Western Australia”
Mine infrastructure is a vital component of the mining and mineral industry and interruptions to its operation can have significant economic implications. In the Pilbara region of Western Australia, where iron ore mining dominates, mine infrastructure commonly includes inland Ore Processing Facilities, various transport corridors, which cover a variety of terrains, commonly linking the mines to the coast, Port Facilities along the north-west coast and associated Non-Processing Infrastructure.
Development of Pilbara mine infrastructure is commonly constrained by being conducted as part of relatively fast-tracked projects, on remote sites with a range of access issues, including lengthy land acquisition accounting for lease, traditional owner and environmental requirements.
While the type and location of mine infrastructure varies widely, geotechnical input required for development can be categorised as site selection, construction of cuts and fills, foundation assessment for structures, monitoring and maintenance of constructed earthworks and recovery post failures.
Engineering geological input has been proven to be a valuable tool in enabling the development and operation of mine infrastructure in this relatively complex environment by:
- Development of early ground models, including engineering geological maps, based on existing information, site reconnaissance and mapping for input to site selection and early engineering;
- Early identification of key geo-uncertainties and geo-hazards and targeting Ground Breaking Investigations (GBI) to resolve such issues;
- Conduct of GBI to provide information for design and earthworks tendering and extrapolation of results between investigation locations on large sites and to in accessible areas;
- Provision of construction support ensuring encountered ground conditions are as interpreted during design and, if not, identify alternative designs that need to be applied; and
- Operational support providing earthworks condition reports, ongoing monitoring, prioritisation of remedial works should requirement for such be identified and rapid response when earthworks failures occur.
Discussion of the above is illustrated by reference to a range of projects conducted by the author in the Pilbara.
John Kennedy is a consulting engineering geologist, with more than 35 years of professional experience. Throughout his career John has supported projects across all phases – from initial site selection, through the various phases of geotechnical investigation and site characterisation, geotechnical design, construction and operation. John places particular emphasis on understanding, and mitigating or allowing for, geo related risk and uncertainties throughout projects. John is skilled at identifying and communicating geotechnical conditions and issues to all relevant stakeholders of the projects.
John routinely works on mining projects, such as Ore Processing Facilities and Non-Processing Infrastructure, transport corridors including heavy haul railways, roads, pipelines and conveyors, quarries for sourcing seawall armour and manufacture of ballast and Select Fill and Port Facilities.
As mining transitions to green energy, John is becoming increasingly involved with geotechnics related to renewable energy generation, in particular, solar and wind power generation, and power transmission networks. John also has extensive experience with geotechnical investigation and analyses of the stability and design of open pit slopes and tailings dams. Whilst particularly focussed on Western Australia, John has worked on projects throughout Australia and in New Zealand, Ghana, Guinea, Liberia, Cameroon, Mongolia, Mexico, Greenland, Indonesia, Vietnam and Papua New Guinea.
In 1996, John formed 4DGeotechnics Pty Ltd, a Perth based consulting company, specialising in providing professional geotechnical services to large primary resource development projects and operations. Since its inception, and under John’s guidance, 4DG has focussed on the development and application of proven professional skills and techniques to maximise the use of existing data and engineering geological mapping to provide early geotechnical input to projects and conduct complex engineering geological and geotechnical investigations, often in remote and extreme locations and often with strict time limitations.
Nina Levy Service Line Manager, Marine Geotechnical and Geophysics Survey at Fugro
“Geotechnics for offshore renewables in WA”
Characterization of the geology offshore Western Australia has been performed for Oil and Gas resource developments for more than 40 years. Interpretation of the data collected has led to greater understanding of the North West Shelf and sections of the WA coastline. The carbonate soils and rocks that reside off our border have been observed to behave differently to other materials and design of oil and gas infrastructure has adapted accordingly.
A new chapter is close to commencing, with plans underway to develop areas of the WA coastline to harness wind energy. Offshore wind developments are an exciting initiative that, together with other renewables initiatives (e.g. hydrogen), will provide WA with alternative sources of power.
The turbines themselves, transmission lines and tie in to/new onshore facilities will need to be designed. As geotechnical professionals, the ground conditions that will interact with the various components of these developments, both over land and water, will need to be assessed.
This presentation will present some thoughts on the road ahead and the potential geotechnical challenges and opportunities that may arise.
Nina has been a geotechnical engineer for more than 20 years. She completed her undergraduate and postgraduate studies at the University of Western Australia in the field civil/ geotechnical engineering, with an additional degree in Mathematics. Nina has worked in Perth and overseas on a range of infrastructure and resources projects. Her current role is with Fugro as the manager of the Marine Geotechnical and Geophysics Survey service line for the Pacific region. Nina was the chair of the Australian Geomechanics Society in 2020-21 and is currently a member of the AGS executive as the immediate past chair.
Barry Lehane Professor, School of Engineering, Civil, Environmental and Mining Engineering, UWA
“The axial stiffness and capacity of screw piles in sand”
Displacement screw piles are used extensively for low and medium rise developments and are a popular solution in cases where resistance to significant uplift loads is required. The ability to re-use screw piles and recent interest in their use as foundations in solar farms and offshore wind and wave applications has renewed interest in improving existing design methods. This presentation presents results from a study undertaken with Dr. Eduardo Bittar (Arup) and the University of Southampton which examined the influence of a range of parameters on screw pile axial performance in sand. The observations made are combined with a database of load tests to formulate a simple method for prediction of screw pile stiffness and capacity using CPT data.
Professor Barry Lehane has worked as a practitioner and academic in geotechnical engineering since 1984. Barry obtained his Civil Engineering degree from University College Cork in Ireland and then worked with Arup Geotechnics in London until he began his PhD at Imperial College, London in 1989. Following completion of his PhD in 1992, he again worked with Arup in London and Hong Kong before taking up a lecturing position at Trinity College in 1994. He moved to Perth in 2002 and has remained as a Professor at the University of Western Australia since then. Barry has published more than 300 technical papers in international journals and conferences, and he continues to consult widely on a wide variety of national and international projects.
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