CRC mining
Project S801
Rock strain, structure, strength and stress
The objective of this project is to provide engineering projects within Earth’s crustal rocks with methods and procedures for a site characterisation and model formulation that reconcile the strain, structure, strength and stress of rock on regional to local scales. In mining engineering, for example, this is required for input to subsequent stress analyses and consequently the safe and economic design of excavations and extraction sequences.
- Project leader: Chris Windsor
Project S802
Discontinuous rock mass analysis
The characterisation of discontinuous rock masses and the prediction of their behaviour in response to mining activity are integral to both surface and underground mining operations. The in situ fragmentation is required for efficient blast design, the assessment of stability of the rock mass surrounding all excavations and the design of appropriate ground support. The project has two basic objectives; back analysis of the performance of a large caving operation and theoretical investigations to characterise the behaviour of discontinuous rock and development of associated computer software to predict their behaviour.
- Project leader: Alan Thompson
Project S803
Optimisation excavation design & sequence
The research will allow mining companies to select an excavation size, shape and sequence that achieve the maximum reconciled grade at the selected cut-off grade. The project will develop research tools to improve data collection quality and efficacy, three-dimensional geotechnical model development, excavation design and excavation performance methodologies.
- Project leader: Ernesto Villaescusa
Project S804
Static and dynamic testing of ground support systems
Static and dynamic laboratory testing of ground support systems to characterise their force-displacement response as well as their energy absorption capabilities. This applied research investigation will lead to the development of practical energy absorption guidelines for the types of reinforcing systems, face restraint and surface support systems used in underground mining. The guidelines will provide quantitative data for the energy absorbed by the reinforcing and support systems or a fully-integrated ground control scheme. This data can then be used by Geotechnical Engineers to design ground support schemes appropriate for expected dynamic failures when mining at depth or in highly stressed conditions.
- Project leader: E Villaescusa
Project S805
Advanced Ground Support Technology
Systematic assessment of ground support to achieve safe and economical extraction of ore. The type of support and reinforcement needed in a particular location is dependent on several factors including the available rock mass strength, the geometry of the excavation, the stresses present in the rock, the blasting practices and the weathering process. This project has been established to review and establish procedures for design of ground support to match observed excavation behaviour. Selection of appropriate materials and components to match likely environmental conditions. Identification and solution to problems associated with installation of ground support systems. Assessment of effectiveness and serviceability of ground support systems.
- Project leader: Ernesto Villaescusa
Project S806
Fill strength and deformability
Minefill is the material placed underground to fill the voids created by mining excavations. It provides overall large scale ground stabilization and allows localized pillar recovery. In addition to providing a working floor or back, minefill may reduce rock burst potential, reduce subsidence and minimize dilution. Minefill is essential to cut & fill, benching and sublevel stoping mining methods.
- Project leader: Ernesto Villaescusa
Project S807
Advanced ground support, hardware and equipment
Despite the many years of rock reinforcement and support usage in mines, there are still many perceived deficiencies associated with the materials, equipment and installation procedures. The research team are often asked to investigate and comment on both existing ground support systems and those that are under development. It is anticipated that these projects will stimulate ideas for improvements to both materials and thee equipment used for installation. These ideas may simply involve adaptation of existing technologies or may lead to new concepts for materials or equipment modifications that can be commercialised. Currently, there are three potential products that have been identified for development and investigation. It is possible that other ideas will evolve over the next 4 years of the project.
- Project leader: Alan Thompson
Project S808
Early strength of shotcrete
Future use of shotcrete in Australian mines will continue and is likely to increase further as mines attempt development within the higher stress regimes and more difficult conditions that generally accompany mining at depth. Faster development rates are required with lower ground support costs and increased safety. Successful implementation of In Cycle Shotcrete (ICS) is a critical to achieve such objectives. Within ICS early re-entry time are required, which presents a conflict between increased productivity and workplace safety. There is a need to reliably determine the early strength of the shotcrete and its adhesion to the underlying rock. In terms of economics, there is also the necessity to economise on development costs, in particular, faster development rates are required with lower ground support costs and increased safety. All of these objectives may be achieved in certain rock conditions using ICS.
- Project leader: Hla SAW