Managing Director of John R Read Associates Pty. Consultant for the Large Open Pit Project and Editor of Guidelines to Open Pit Slope Design.
Dr Read commenced working as a project engineering geologist on the investigation and
construction of hydro-electric schemes, water supply dams, highways and mining infrastructure
projects throughout Australia, Papua New Guinea and Indonesia in late 1961. From 1980 to 1984 he
was the Superintending Engineering Geologist at the Bougainville Copper Mine in Papua New Guinea
before moving to the USA, to Purdue University, where in 1987 he completed his PhD in
geotechnical engineering. Following graduation he worked on USDOE programs for the
underground disposal of nuclear waste in Washington State and Texas, and on slope stability and
open pit metalliferous mine design tasks in Mexico, Chile, and Papua New Guinea.
In 1990 Dr Read returned to Australia and commenced his own geotechnical engineering practice,
principally high-level peer reviews directed at assessing slope design and performance at mines
operated by a number of international metalliferous and coal mining companies. In 1994 he
accepted a contract appointment with Australia’s national research organisation, CSIRO, to be
Deputy Chief of the Division of Exploration & Mining, with responsibility for developing and
coordinating strategies for the performance of mining related research within CSIRO.
In April 2004 Dr Read stepped back from his administrative roles in CSIRO to initiate and then lead a
major industry-funded CSIRO research project focussed on the stability of rock slopes in large open
pit mines (the LOP project), the principal objective of which was to perform research that improved
current methods of predicting the stability of rock slopes in open pit mines.
Dr Read retired from CSIRO and leadership of the LOP project in June 2014, but continues working
with the mining industry as an independent consultant.
Theme: The objectives of Slope Stability 2018 are i) to consolidate the knowledge gained and show how techniques have improved since the book Guidelines for Open Pit Slope Design was published in 2009, ii) to provide real and evidenced results, and iii) to provide direction for further improvements beyond 2018. The objective of this keynote address is to set the scene for the conference by over viewing what has taken place in the open pit slope design world since 2009 by critically examining what has worked, what is not working, and what is considered to be the best approach to satisfy best practice beyond 2018
Professor Phil M. Dight, Professor Geotechnical Engineering, Australian Centre for Geomechanics, Perth, Australia
Phil has been involved with the development and design of ground support for mining applications since 1975. He was a partner in BFP Consultants until BFP was acquired by Coffey Mining. Phil has extensive consulting experience in the geotechnical aspects of the mining industry, and has worked on open pit and underground metalliferous mining problems. In 1985 he was awarded the Manuel Rocha Medal by the International Society of Rock Mechanics for his work in open pit mining and use of ground support to improve pit stability. His ground support algorithm has been adopted by Rocscience in its evaluation of ground support in Phases®, and a variation has been adopted by ITASCA in the Bonded Block Model. In the 1980s with Dr Peter Fuller, he undertook research into ground support work in a number of AMIRA sponsored projects based on open stope mining. Much of that early research work has now been formalised in the literature by others. Phil joined the ACG in 2008 and has since been working on stress memory effects in rocks, ground support applications, slope stability problems (including the use of microseismicity to understand failure mechanisms), and 3D rock properties. Most recently, Phil commenced a four year MRIWA project aimed at investigating the issues of strainburst vulnerability in underground mines.
It is a well-known concept that you cannot manage if you do not measure. This can be readily applied to slope stability where instability and failure of pit slopes can be identified from properly designed monitoring programs. However, understanding the actual mechanism is often not well-understood, so even if you measure the instability you may not recognise the mechanism. In this paper, examples of good slope monitoring and mechanism interpretation will be provided. Also, in one case the use of subsurface monitoring was needed to provide a complete understanding of the failure processes and the most likely scenario of instability.
PM Dight, Australian Centre for Geomechanics and The University of Western Australia, Australia
M Salvoni , Australian Centre for Geomechanics and The University of Western Australia, Australia; Talison Lithium Pty Ltd, Australia
Global Mining Hydrologist
Geoff Beale has worked for 40 years in surface and groundwater control for the minerals industry. He has worked in over 65 countries worldwide, in all major industrial commodities, and in all climatic zones. Geoff is most noted for his global knowledge of open pit and underground mine dewatering projects, and has been involved with many of the world’s largest dewatering operations. He has broad experience in the operational and environmental aspects of leach pads, waste rock facilities and tailing systems, and has played a lead role in the design and monitoring of closure programs for several mine sites. In recent years, he has studied the role of water in geotechnical engineering, gathering data and experience from many mine sites worldwide.
Theme: An objective of the Large Open Pit (LOP) Project was to improve the understanding of the occurrence and the role of pore pressures in pit slope engineering. New ideas have been developed and investigated by analysing geotechnical and hydrogeological monitoring data from many mine sites worldwide. Standard methods have been developed for inputting pore pressures into slope stability analysis, to investigate the sensitivity of the slope to water pressure and the cost-benefit of implementing slope drainage systems. The importance of hydromechanical coupling is now better understood. There is a better appreciation of the need to optimise the mine site layout and minimize the extent to which seepage from mine facilities impacts the pit slopes, and the awareness of the management of surface water for minimizing transient pore pressures has improved.
Emeritus professor in rock mechanics at the Higher Technical School of Mining and Energy Engineers, Polytechnic University of Madrid (UPM), Spain
Pedro Ramírez Oyanguren, Emeritus professor in rock mechanics at the Higher Technical School of Mining and Energy Engineers, Polytechnic University of Madrid (UPM), Spain.
Pedro has worked in rock mechanics, applied to mining since 1965. Firstly, during seven years, as a geotechnical engineer in a potash mine in the north of Spain (Potasas de Navarra, S.A), later as a partner in the international geotechnics and environmental consultancy Dames & Moore, during 10 years. Since the early 80´s he has held tenure at the Polytechnic University of Madrid and provides geotechnical advice on many Spanish mining operations.
Pedro has wide experience as a consultant and in teaching rock mechanics applied to both underground and open pit mining and in both metal and sedimentary mining. On civil engineering projects, he has worked on slope stability issues and tunnelling. In addition he has been heavily involved in rock cutting using TBM´s. Predominantly, though not exclusively, Pedro centres his main activities as a consultant on the mining operations of the Iberian Pyrite Belt.
As a teacher, Pedro has guided many of the university´s numerous courses as well as doctorate programs in Spain, France and Latin America. As an investigator he has participated in many European Community and nationally funded investigation programmes.
Theme: The purpose of this paper is to present the main problems of slope stability that have occurred in the IBP and Ossa Morena geological zones and the solutions that have been given to them. It is intended to guide future open pit miners so they can design stable slopes in both zones.
General Manager of the Itasca Office in Sweden. Adjunct Professor in Rock Mechanics and Rock Engineering at the Luleå University of Technology
Jonny Sjöberg is a rock mechanics engineer with experience in operations, research and consulting within mining and civil engineering. He holds a Ph.D. in the area of open-pit slope stability, and has consulted on rock mechanics issues for a number of open pit operations, primarily in Europe, over the last 20 years. During his career, he has worked for several mining and consulting companies in Sweden and the U.S. Currently, he is the General Manager of the Itasca Office in Sweden. He is also appointed Adjunct Professor in Rock Mechanics and Rock Engineering at the Luleå University of Technology.
Rodrigo Silva Mandiola
Head of Geotechnical Engineering: The Doña Inés de Collahuasi Mining Company
Rodrigo Silva-Mandiola is a mining engineer with almost 20 years of experience in geotechnical engineering, both in consulting and operation. His early consulting experience included solving complex slope stability problems applying state-of-the-practice tools such as commercial three dimensional numerical modeling packages, providing geotechnical design recommendations for large open pits in Chile and other countries. Since 2008, Mr. Silva-Mandiola has been leading the Geotechnical Group at Cia. Minera Doña Inés de Collahuasi, in northern Chile. At this operation, he has been involved in the implementation of the best operational practices of the industry as well as in slope depressurization processes, improving the hydrogeological instrumentation and depressurization results at Rosario Mine. The particular complexities of the Collahuasi operations have allowed Mr. Silva-Mandiola to develop a strong expertise in slope remediation and instability mitigation, adopting the newest technologies on slope monitoring systems as well as leading the implementation of a preventive geotechnical engineering viewpoint on the potential operational interaction aimed at mitigating the effect of potential instabilities on people´s safety and business risks.
Theme: The purpose of this keynote lecture is presenting the geotechnical experience gained at Rosario Mine since its inception. Rosario Mine started almost 20 years ago, being a complex mining site since the beginning. This complexity is due to several adverse geotechnical conditions, such as: low quality rock mass, presence of significant underground water and a complex structural setting with many major faults. Therefore, in the initial stages of mining, most of the efforts were placed on maintaining an operational condition while gaining understanding of the site to incorporate it in the future design stages to improve the stability condition. New practices and technics have been constantly researched to improve the mining business. This lecture presents some of those developments, and their evolution with time, particularly facing the challenges of applying best practice in the development of a very large open pit beyond 2020 and until year 2081
Professor Geotechnical Engineering, Dept. Civil & Environmental Engineering, University of Alberta, Edmonton, Canada.
Dr. Derek Martin started his career in 1972 and has over 40 years of experience in geotechnical engineering associated with tunnels, dams and slopes. He holds a BSc in geology, and a Masters of Engineering and a PhD in Geotechnical Engineering. His early years were spent on construction sites for major slope stability and underground projects. In 1987 he joined AECL, where he directed the geomechanics research at the Underground Research Laboratory in southeastern Manitoba and was senior adviser to the Director of the Canadian Nuclear Fuel Waste Management Program. From 1995-1999 he served as Associate Director of the Geomechanics Research Centre at Laurentian University, working on the deep mining projects in the Sudbury basin. Since 2000 Dr. Martin has been Professor in Geotechnical Engineering at the University of Alberta where he holds an NSERC Industrial Research Chair.
Between 2007-2011, Dr. Martin served as ISRM Vice-President for North America. He has authored over 200 technical papers on rock engineering and is a Fellow of the Engineering Institute of Canada and a Fellow of the Canadian Academy of Engineering.
Dr. Martin has worked in over 10 countries providing independent geotechnical review on major mining and civil projects.
Theme: The LOP Book "Guidelines for Open Pit Slope Design in Weak Rocks” will be published in the fall of 2017. It was recognised by the LOP Sponsor’s Management Committee that the 2009 Guidelines for Open Pit Slope Design were focused primarily on open pit slopes in strong rocks as defined by the International Society for Rock Mechanics (ISRM) strength classification (i.e. a grade of ≥ R2). As such, it did not fully consider the challenges that are often associated with open pits in ‘weak rocks’ (R0 to ≤ R2). Weak rocks typically require flatter excavated slope angles than are adopted in strong rocks, and these flatter slopes can have significant economic implications. It is therefore critical that the presence of weak rocks is recognised early in the design process, which could then differ from the approach used for strong rocks. This recognition may require a different site characterisation and design approach. This book has therefore been prepared as an addendum to the original 2009 Guidelines with the specific purpose of providing a framework for characterising, analysing and designing pit slopes in weak rocks. This keynote will address the issue of the Strength of Weak Rocks in Open Pit Slope Design, drawing upon the case histories described in the LOP Book that illustrate the various approaches currently used in practice.