Professor David Williams

Professor

School of Civil Engineering
Faculty of Engineering, Architecture and Information Technology
d.williams@uq.edu.au
+61 7 336 53642

Overview

Professor David John Williams is the Director of the Geotechnical Engineering Centre within the School of Civil Engineering at The University of Queensland, an industry-funded centre that has attracted AUD10 million in funding over the last 15 years. He also manages the industry-sponsored Large Open Pit Project, involving 10 global mining company sponsors, with current funding of USD1 million per year. He has over 40 years of teaching, research and consulting experience, and is internationally recognised for his expertise and experience in mine waste management and mine closure, pertaining to tailings dams in particular. He was a member of Expert Panel investigating technical causes of Brumadinho tailings dam failure and is on a number of Tailings Independent Technical Review Boards, including for Escondida. He authored in 2009 and 2016 Tailings Management Handbook, as part of the Commonwealth Leading Practice Sustainable Development Program for the Mining Industry. He is on Working Party for the Australian National Committee for Large Dams Guidelines on Tailings Dams – Planning, Design, Construction, Operation and Closure, published in 2012, with an Addendum in 2019.

David received his BE (Hons I) in Civil Engineering from Monash University in 1975 and his PhD in Soil Mechanics from the University of Cambridge in 1979. His research interests include:

  • Physical characterisation of mine tailings deposition, including beaching, hydraulic sorting, sedimentation, consolidation, desiccation and loading
  • Store and release cover systems for potentially acid forming mine wastes
  • Co-disposal of mine tailings and coarse-grained mine wastes
  • Dewatering and densification of mine tailings
  • Dewatering of mineral products
  • Moisture movement within mine wastes
  • Settlement of coarse-grained mine wastes
  • Strength of coarse-grained mine wastes
  • Engineered rehabilitation of mine sites
  • Risk assessment and cost-effectiveness analysis of mine site rehabilitation and closure
  • Long-term seepage and runoff from mine tailings storages
  • Characterisation of potentially acid forming waste rock dumps
  • Application of high-resolution digital stereo-photography to monitoring erosion from mine waste slopes
  • Mined landform evolution and design

Research Impacts

Professor Williams' research on mine tailings continues to be applied to improve the dewatering and densification of tailings deposited as a slurry. He developed the store and release cover system for potentially acid forming mine wastes for application in semi-arid and seasonally dry climates, which has been applied worldwide. He characterised the deposit formed on the pumped co-disposal of coal mine washery wastes; a method that has been widely adopted in the coalfields of eastern Australia and Indonesia. The co-disposal of coarse-grained mine wastes and tailings is also being applied. His research on the wetting-up of mine waste rock dumps has contributed to understanding of rainfall infiltration into and seepage from waste rock dumps.

The shear strength and settlement of coarse-grained mine wastes have become important as the scale of waste rock dumps and spoil piles increases. Professor Williams has been a pioneer in the application of risk assessment and cost-effectiveness analysis to mine site rehabilitation and closure. In addition, he applied high-resolution digital stereo-photography to monitoring erosion from mine waste slopes. He has pioneered mined landform evolution and design.

Qualifications

  • PhD, University of Cambridge
  • Bachelor of Engineering (Honours1), Monash University

Publications

  • Islam, Shriful, Williams, David J., Llano-Serna, Marcelo and Zhang, Chenming (2020). Settling, consolidation and shear strength behaviour of coal tailings slurry. International Journal of Mining Science and Technology doi: 10.1016/j.ijmst.2020.03.013

  • Clarkson, Luke, Williams, David and Seppälä, Jaakko (2020). Real-time monitoring of tailings dams. Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 1-15. doi: 10.1080/17499518.2020.1740280

  • Contreras, L. F., Serati, M. and Williams, D. J (2020). Bayesian approach for the assessment of sufficiency of geotechnical data. International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, Perth, WA Australia, 12-14 May 2020. Perth, WA Australia: Australian Centre for Geomechanics (ACG).

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Grants

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Available Projects

  • Risk assessment and cost-effectiveness analysis techniques are becoming an essential tool in defending the choice of rehabilitation strategy for open cut mines. An existing risk assessment and cost-effectiveness analysis tool developed for the rehabilitation of open cut coal mine spoil areas will be applied to a number of typical spoil areas, and the cost-effectiveness of different rehabilitation strategies assessed.

  • Surface coal mining by dragline leaves a legacy of surface disturbance in the form of spoil piles. The rehabilitation of spoil pile areas involves substantial earthworks, which constitute the major cost of rehabilitation. Minimising the amount of earthworks required minimises the cost of rehabilitation. Typically, spoil piles are reshaped from the angle of repose of the spoil (about 37 degrees) to a constant angle of less than 10 degrees. An alternative strategy would be to reproduce, as closely as possible, the pre-mining distribution of slope angles and lengths, which can be determined from pre-mining topographic plans. By comparing the pre-mining and post-mining topographic plans, it is possible to determine the minimum earthworks required to mimic the general pre-mining landform.

  • The requirements of a cover material for potentially contaminating materials, whether they be sulphidic or saline mine wastes, industrial, or domestic wastes, is that the material can achieve a low hydraulic conductivity, preferably hold saturation, be resistant to desiccation and erosion, and possibly be suitable as a growth medium. There is potential for mixtures of inert, durable waste rock and tailings to satisfy these requirements. A range of waste rock and tailings mixtures will be assessed for their suitability in the laboratory.

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Publications

Book

Book Chapter

  • Franks, Daniel M., Littleboy, Anna and Williams, David (2020). Global research consortium on tailings. Towards Zero Harm: A Compendium of Papers Prepared for the Global Tailings Review. (pp. 231-237) edited by Bruno Oberle, David Brereton and Antonia Mihaylova. London, United Kingdom: Global Tailings Review.

  • Williams, David John (2015). Placing soil covers on soft mine tailings. Ground Improvement Case Histories: Compaction, Grouting and Geosynthetics. (pp. 51-81) edited by Buddhima Indraratna, Jian Chu and Cholachat Rujikiatkamjorn . Kidlington, Oxford United Kingdom: Elsevier. doi: 10.1016/B978-0-08-100698-6.00002-7

  • Topal, E. and Williams, D. J. (2013). Mine waste rock management. Australasian mining and metallurgical operating practices. (pp. 76-77) edited by W. J. Rankin. Carlton, VIC, Australia: Australasian Institute of Mining and Metallurgy.

  • Williams, David J. (2005). Placing covers on soft tailings. Ground Improvement: Case histories. (pp. 491-512) edited by Buddhima Indraratna and Jian Chu. Amsterdam ; Boston: Elsevier.

  • Williams, D. J. (2001). Assessment of embankment parameters. Slop Stability in Surface Mining. (pp. 275-284) edited by Hustrulid, W. A., McCarter, M. C. and van Zyl, D. J. A.. Littleton, Colorado, USA: Society of Mining, Metallurgy and Exploration.

  • Williams, D. J. (1996). Minimisation and Management of Solid Wastes. Environmental Management in the Australian Minerals and Energy Industry. (pp. 157-188) edited by Mulligan, D. R.. Sydney: UNSW Press in association with Australian Minerals and Energy Environment Foundation.

Journal Article

Conference Publication

Grants (Administered at UQ)

PhD and MPhil Supervision

Current Supervision

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Master Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

  • Doctor Philosophy — Principal Advisor

  • Master Philosophy — Principal Advisor

  • Doctor Philosophy — Associate Advisor

    Other advisors:

  • Doctor Philosophy — Associate Advisor

    Other advisors:

  • Doctor Philosophy — Associate Advisor

    Other advisors:

  • Doctor Philosophy — Associate Advisor

    Other advisors:

  • Doctor Philosophy — Associate Advisor

    Other advisors:

  • Doctor Philosophy — Associate Advisor

  • Doctor Philosophy — Associate Advisor

  • Doctor Philosophy — Associate Advisor

  • Doctor Philosophy — Associate Advisor

    Other advisors:

Completed Supervision

Possible Research Projects

Note for students: The possible research projects listed on this page may not be comprehensive or up to date. Always feel free to contact the staff for more information, and also with your own research ideas.

  • Risk assessment and cost-effectiveness analysis techniques are becoming an essential tool in defending the choice of rehabilitation strategy for open cut mines. An existing risk assessment and cost-effectiveness analysis tool developed for the rehabilitation of open cut coal mine spoil areas will be applied to a number of typical spoil areas, and the cost-effectiveness of different rehabilitation strategies assessed.

  • Surface coal mining by dragline leaves a legacy of surface disturbance in the form of spoil piles. The rehabilitation of spoil pile areas involves substantial earthworks, which constitute the major cost of rehabilitation. Minimising the amount of earthworks required minimises the cost of rehabilitation. Typically, spoil piles are reshaped from the angle of repose of the spoil (about 37 degrees) to a constant angle of less than 10 degrees. An alternative strategy would be to reproduce, as closely as possible, the pre-mining distribution of slope angles and lengths, which can be determined from pre-mining topographic plans. By comparing the pre-mining and post-mining topographic plans, it is possible to determine the minimum earthworks required to mimic the general pre-mining landform.

  • The requirements of a cover material for potentially contaminating materials, whether they be sulphidic or saline mine wastes, industrial, or domestic wastes, is that the material can achieve a low hydraulic conductivity, preferably hold saturation, be resistant to desiccation and erosion, and possibly be suitable as a growth medium. There is potential for mixtures of inert, durable waste rock and tailings to satisfy these requirements. A range of waste rock and tailings mixtures will be assessed for their suitability in the laboratory.

  • Coal washing is carried out in order to produce a product that meets market specifications. The waste products from washing coal are coarse reject, typically in the size range from 50 mm down to 0.5 mm and tailings typically passing 0.5 mm. Conventionally, the two waste streams are disposed of separately, the coarse reject to surface dumps and the tailings as an aqueous slurry to a surface storage facility. A number of mines dispose of the two waste streams together by pumping. The applicability of the pumped co-disposal of coal washery wastes depends on a number of parameters, which can be assessed by laboratory testing and field trials. The focus of the thesis will be laboratory testing for suitability to pumped co-disposal.

  • Laboratory leachate columns are used to simulate the leachate likely to be generated under field conditions. However, the columns are typically put through regular cycles of air-flow and flooding, during which leachate samples are collected for analysis. The Australian climate is anything but regular. A number of columns will be filled with potentially acid forming waste rock, and each subjected to a different sequence of air-flow and flooding, ranging from a regular sequence of events to replicating actual climatic conditions, and the resulting leachate quality and quantity compared.

  • Mine tailings are conventionally disposed of as an aqueous slurry to a surface storage facility. During the operation of the facility, water is decanted from the tailings and recycled to the processing plant. Incident rainfall must also be accommodated, with water lost to evaporation, seepage and entrainment within the tailings. On closure of the facility, the water balance includes incident rainfall, infiltration, evaporation and seepage. The laboratory column experiment will impose various aqueous boundary conditions on a 2 m high column of tailings, which will be instrumented to determine the moisture and suction profiles of the tailings and hence the direction and magnitude of any flow.

  • Erosion off disturbed slopes, such as mined land, is difficult to measure. Conventionally, sediment traps are constructed at the toe of the slope to collect both bed load and suspended sediment. However, these systems are difficult and expensive to maintain. An alternative method is the use of high-resolution digital stereo-photographs, from which a three-dimensional image of the slope can be constructed using specialised software. The three-dimensional image highlights erosion gullies and sediment plumes, and allows the erosion loss and downstream sedimentation to be calculated digitally. The surface texture of the slope can also be estimated digitally from close-up digital photographs. This technique will be applied to mine slopes in the Ipswich Coalfields, which were studied 12 months earlier, allowing an accurate picture to be obtained of the erosion loss over the 12 month period.