Welcome to the Mining and Geomechanics Research Group

Introduction

The expertise of this research group covers many areas in mining and geotechnical engineering. The group is particularly strong in the areas of Geostatistics and Geomechanics. Current research activities include:

Geostatistical applications in mining and environmental engineering (Dowd and Xu)
Our geostatistical research covers the characterisation of spatial variables in mining, petroleum and environmental contexts and has been applied nationally and internationally to resource and reserve estimation; the simulation of orebodies, hydrocarbon reservoirs and geological structures; the characterisation of rock masses for mining, environmental and geothermal applications; and for quantitative risk assessment in environmental and mining applications. More detailed information about this research can be found here.

Stochastic modelling of fractures and fracture network in rock masses (Dowd and Xu)
Fractures and fracture networks have a determining role in the behaviours of rock masses for most engineering applications. The aim of this research is to investigate suitable statistical methods and tools to construct realistic fracture models for rock masses. Such models provide more accurate solutions to many practical engineering problems such as slope design of surface mining operation, stability analysis of underground excavations and flow transport through fractured rock masses.

Mine finance and mineral economics (Dowd and Xu)
Risk assessment is a major component of decision-making for new mining projects. This research deals with various methods of quantifying risks involved in mining investment due to technical, financial and economic uncertainties. The research has produced MINVEST - an award winning financial evaluation package for the minerals industry which has user licenses worldwide.

Computer Aided Mine Design - CAMD (Dowd and Xu)
The main focus of this project is the research and development of algorithms and computer packages for the scheduling of surface and underground mining operations, for the optimal design of open pit mines and for the CAMD of underground mines. The research also includes the use of Geographical Information Systems (GIS) for the environmental impact assessment of mining operations.

Mixed-mode fracture toughness testing for rocks (Dowd and Xu)
This research extends the success of previous research on Mode I fracture toughness testing using the cracked chevron-notched Brazilian disc (CCNBD) , which was adopted in 1995 by the International Society for Rock Mechanics (ISRM) as a suggested method for Mode I rock fracture toughness testing. The aim of the research is to identify and analyse suitable specimen geometries and to develop procedures for the measurement of mixed mode fracture toughness of rock materials.

Failure mechanism evolution for rigid rock blocks (Priest)
Failure of rigid rock blocks is a significant factor in causing instability in surface and underground mines. Over the last 10 years Professor Priest has developed a major Excel spreadsheet 'Wedge' for calculating the factors of safety and failure mechanisms for tetrahedral blocks exposed at overhanging and non-overhanging rock faces. Preliminary work with this spreadsheet has indicated that an incremental increase in the support pressure applied to the rock face causes an 'evolution' in the predicted failure mechanism, with associated step changes in the estimated factor of safety. The aim of this research project is to study this phenomenon and investigate the implications for rock support design.

Comparisons between three-dimensional yield criteria for fractured and intact rock (Priest)
Yield criteria for rock fall into two broad categories: those based on yield criteria developed and adapted for soils; and those based on the Hoek-Brown yield criterion. The first group of criteria source their input data from one or more of the parameters uniaxial compressive strength, cohesion and friction. The second group of criteria source their input data from uniaxial compressive strength, coupled with mineralogical and structural properties of the rock. Although some authors have attempted to compare the predictions of the wide range of published criteria, the results have not been entirely satisfactory due to disparities in the input data and the difficulties in extrapolating a two-dimensional criterion into three-dimensions. Over the last year Professor Priest has developed a strategy for achieving a consistent basis for comparing yield criteria for rock. This strategy is based on using the Hoek-Brown criterion as a single 'front end' for calculating the input parameters for the complete range of criteria. This strategy is currently being applied in a comprehensive comparison of all published criteria, including the new three-dimensional 'Priest' yield criterion.

Validation of the generalised Kirsch equations for the stability analysis of deep petroleum wellbores (Priest)
The degree to which in situ stresses are concentrated adjacent to a petroleum wellbore depends on the orientation of the borehole relative to the orientation of the in situ stresses, the location of the point of interest and the radius of the borehole. Most workers in this area have adopted the generalised from of the Kirsch equations reported by Fairhurst (1968) and published by Bradley (1979). These equations are required when none of the remote principal stresses are aligned parallel to the wellbore axis. The generalised Kirsch equations will be checked and validated by numerical modelling. The three-dimensional stress modelling software 3DEC and FLAC3D will initially be set up to validate the standard Kirsch equations under a range of boundary conditions and rock properties. The stress conditions will then be modified to assess the validity of the generalised equations when the conditions of plane strain are not fully satisfied, and when the rock is not continuous, homogeneous, isotropic and linearly elastic. It is expected that the outcome of this research will be the specification of a range of conditions under which the generalised Kirsch equations are applicable.

Mine Design Using Simulation and Animation Models (Sturgul)
Discrete system simulation is an important tool for mining engineers in mine design practice. A simulation and animation model can assist in predicting the future production of the mine, the equipment selection such as the correct mix of trucks and loaders, the numbers and locations of repair facilities and spare parts, and the location of in pit crushers, etc. to name but a few. The first mine to be totally designed by simulation from the beginning was the Lihir Mine in Papua New Guinea in 1996. Now, simulation models are being used in mines in Australia and New Zealand and throughout the world. Research in mine simulation models continues in the areas of 3-D animation models, WEB-based simulation and object oriented simulation. This research aims to incorporate new developments into the Australian and worldwide mining operations.

Shear-induced fracture slip and permeability change - implications for long term performance of a deep geological repository (Min)
While characterizing permeability is one the most important tasks for the feasibility of geological repository of nuclear waste, it is important to recognize that fluid-carrying ability of underground rock is a dynamic variable under the life span of geological repository. The focus of the project is to investigate the thermal stress generated from the heat-generating nuclear waste and its impact on the possible shear slip of fractures around the geological repository. The thermomechanical analysis is conducted by a partial differential equation solver and DFN-DEM method (discrete fracture network - discrete element method) is adopted for the calculation of fluid flow in fractured rock mass. The funding is provided by the Swedish Radiation Safety Authority.

Master program and short training courses
The group also run the following master program and short training courses:

• Master of Geostatistics
• Continuous professional development (CPD) short training course in mineral resources estimation
• Continuous professional development (CPD) short training course in mine finance and valuations
• Mine System Simulation and Animation short courses. Each year several short courses from 3 to 4 days duration are offered on this subject. Last years such short courses were held in Peru, New Zealand and Australia (Perth).
  
  

Professor Peter Dowd
Dr Chaoshui Xu
Dr Ki-Bok Min
Professor Stephen Priest
Professor John Sturgul