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Proceedings Of The 2006 Coal Operators' Conference, Naj Aziz
Proceedings Of The 2006 Coal Operators' Conference, Naj Aziz
Resource Operators Conference
Proceedings of the 2006 Coal Operators' Conference. All papers in these proceedings are peer reviewed.ISBN: 1 920806 48 2.
Methods Of Interpreting Ground Stress Based On Underground Stress Measurements And Numerical Modelling, Jan Nemcik, W. J. Gale, M. W. Fabjanczyk
Methods Of Interpreting Ground Stress Based On Underground Stress Measurements And Numerical Modelling, Jan Nemcik, W. J. Gale, M. W. Fabjanczyk
Resource Operators Conference
This paper presents several new methods to help interpretation and understanding of ground stress. The methods are based on data from 239 stress measurements conducted in the virgin ground in NSW and Queensland mines and computational models simulating large scale faulted ground behaviour. The underground stress regime plays an important role in mining profitability and safety however, understanding of the stress tensor is often difficult due to its mathematical complexities and non-intuitive behaviour. The aim of this study is to explain stress distribution in faulted ground, its origin and propose several methods of stress interpretation. Major findings presented in this …
A New Real Time Personal Respirable Dust Monitor, A. D. Gillies, H. W. Wu
A New Real Time Personal Respirable Dust Monitor, A. D. Gillies, H. W. Wu
Resource Operators Conference
A new personal respirable dust monitor developed by Thermo Electron Corporation under a project funded by the US National Institute of Safety and Health (NIOSH) has generated promising results in underground coal mine testing performed in the US recently. An Australian Coal Association Research Project funded study has been undertaken to evaluate this new real-time dust monitor for personal respirable dust evaluation use particularly in engineering studies. It is believed to be the first personal dust monitor instrument (PDM) for use on mine faces that reliably delivers a near-real-time reading. It can quickly highlight high dust situations and allow the …
Why Uniaxial Compressive Strength And Young's Modulus Are Commonly Poor Indicators Of Roadway Roof Stability - Except In The Tailgate, M. Colwell, R. Frith
Why Uniaxial Compressive Strength And Young's Modulus Are Commonly Poor Indicators Of Roadway Roof Stability - Except In The Tailgate, M. Colwell, R. Frith
Resource Operators Conference
For many years underground rock mechanics and in particular, roadway/tunnel roof stability has been underpinned by the often unchallenged assumption that roof strength (as defined by the UCS) and stiffness (E) are key stability controls. This has logically led to the proliferation of laboratory testing of rock specimens and the development of indirect geophysical methods to gain estimates of these two rock parameters. Furthermore, many design methods are significantly focussed on replicating rock mass behaviour through either intact or failed constitutive models. Demonstrably the strength and stiffness of the host rock material is commonly used as one of the key …
Ground Control In Coal Mines In Great Britain, J. Arthur
Ground Control In Coal Mines In Great Britain, J. Arthur
Resource Operators Conference
In deep coal mining support of the underground roadway is fundamental and without knowledge of the mechanics of ground control a mine is unlikely to be operating safely and efficiently. It is therefore important for the support system to be designed satisfactorily for the size of the excavation required and to do so an understanding of the behaviour of the surrounding strata is required. Over the last 15 years there has been a major change in the mining industry and the support systems adopted. Roofbolting has been adopted as the primary support system, the industry has been privatised, legislation has …
Rapid Rating Using Coal Mine Roof Rating To Provide Rapid Mine Roof Characterisation From Exploration Drilling, J. Calleja
Resource Operators Conference
The Australian coal industry is currently experiencing rapid expansion with many companies fast tracking the development of new mines. In many cases, operators are collecting large quantities of exploration drilling data for pre-feasibility and feasibility studies as well as for operational start-up and mine expansion. “Rapid Rating” is a new method for calculating the Coal Mine Roof Rating (CMRR). It has been designed to allow large quantities of exploration data to be processed quickly to provide a standardised indicator of geotechnical conditions. It is intended to make CMRR more readily available to mine operators. When the CMRR was first developed …
Observations On The Variation In Acoustic Emissions With Changes In Rock Cutting Conditions, E. Williams, P. Hagan
Observations On The Variation In Acoustic Emissions With Changes In Rock Cutting Conditions, E. Williams, P. Hagan
Resource Operators Conference
The emission of acoustic signals or micro seismic activity in rock subjected to stress is a well established phenomenon that has been exploited in geomechanics for example to understand changes in stress levels around excavations in active mine areas. Another potential application is in the area of rock cutting. The finding of a study to investigate whether changes in rock cutting conditions are reflected in the nature of acoustic signals generated in rock is presented. A test facility was established comprising a linear rock cutting machine, acoustic transducer and data acquisition system. The study examined changes between a new and …
Recovering From Major Roof Cavities On The Longwall Face - A Current Perspective, R. Frith
Recovering From Major Roof Cavities On The Longwall Face - A Current Perspective, R. Frith
Resource Operators Conference
Recovering from roof cavities on the longwall face is an endemic aspect of longwall mining and this is especially the case today as longwall faces are wider and higher than they have ever been, yet powered support ratings are effectively technology constrained. There is little doubt that the ever-increasing dimensions of longwall faces are consequently increasing the likelihood of major roof falls occurring, especially in those more challenging geotechnical environments containing poor immediate roof conditions at depths of cover greater than 250 m. As a result, the efficiency and safety of longwall roof cavity recoveries is being given increased attention …
Joint Structure And Coal Strength As Controls On Rib Stability, Ross W. Seedsman
Joint Structure And Coal Strength As Controls On Rib Stability, Ross W. Seedsman
Resource Operators Conference
The assessment of the stability of coal ribs needs to consider not only the impact of the cleating and jointing in the coal but also the possible onset of failure of the coal itself. The same planar, wedge and toppling failure modes seen in pitwall slopes can be present in underground roadways. A 20o offset of the roadway from the strike of the through-going joints reduces the fall hazard, but a 35o offset may be required to reduce delays in installing support. Mining-induced fractures (MIF) in coal may be a manifestation of brittle rock behaviour and its preferential location at …
Airborne Geophysical Techniques, M. Armstrong, A. Rodeghiero
Airborne Geophysical Techniques, M. Armstrong, A. Rodeghiero
Resource Operators Conference
Airborne geophysical surveys have been used extensively in the mineral exploration industry predominantly for the delineation of metalliferous deposits. Recent advances in technology and the integration of multiple geophysical data-sets including aeromagnetic, radiometric and gravity surveys can provide useful information on lithology and structure. Additionally advances in data analysis, processing and image enhancement techniques have improved the resolution of geophysical datasets so that very subtle variations in the geophysical responses can be identified. High resolution aeromagnetic and radiometric surveys have recently been acquired over the Dendrobium mine district in the Illawarra Coal Fields. The primary objective of this survey was …
An Integrated Real-Time Roof Monitoring System For Underground Coal Mines, B. Shen, H. Guo, A. King, M. Wood
An Integrated Real-Time Roof Monitoring System For Underground Coal Mines, B. Shen, H. Guo, A. King, M. Wood
Resource Operators Conference
CSIRO has been conducting a five-year research project under the sponsorship of JCOAL and Ulan Mine to develop a real-time roof monitoring and roof fall warning system for underground coal mines. A preliminary system has been developed and successfully trialled twice in the gateroads at Ulan Mine during 2004 and 2005. The system integrates the displacement monitoring, stress monitoring and seismic monitoring in one package. It includes: • GEL multi-anchor extensometers • Vibrating wire uniaxial stress meters • ESG seismic monitoring system with microseismic sensors and high frequency AE sensors. The monitoring system has been automated and the data are …
The Use Of Downhole Presometers Implications For Modern Underground Mines, J. Doyle, G. Poole
The Use Of Downhole Presometers Implications For Modern Underground Mines, J. Doyle, G. Poole
Resource Operators Conference
An understanding of the hydrogeological environment of the strata over and about an operating mine provides some insight into the effectiveness of gas drainage, the identification of potential difficult drainage areas and the behaviour of overlying aquifers during mining. Bore hole piezometers have been routinely installed in BHP Billiton’s exploration holes for many years. The instruments were developed as one of the outcome of NERDCC research grants completed in 1983 and 1986. Piezometers and geophones packaged to survive the difficult environments of the Southern Coalfield remain operational and are routinely read today, twenty years after their installation. The data acquired …
Pike River Coal - Hydraulic Mine Design On New Zealand's West Coast, P. Whittall
Pike River Coal - Hydraulic Mine Design On New Zealand's West Coast, P. Whittall
Resource Operators Conference
Pike River Coal Limited is in the process of developing the Pike River Coal Mine in the Paparoa Ranges of New Zealand’s South Island. The mine will be developed to extract a coking coal deposit of the Brunner Seam, some 46 km north-east of Greymouth, using a combination of continuous miners and hydraulic extraction . The mining area is located within Department of Conservation (DOC) land and is adjacent to the escarpment of the Paparoa Range and the Paparoa National Park. As such, the major restriction to planned extraction is protection of: • The western escarpment; • Vertical and sub-vertical …
Advances In Surface Seismic Acquisition, Processing And Interpretation, A. Rodegheiro, L. Fredericks
Advances In Surface Seismic Acquisition, Processing And Interpretation, A. Rodegheiro, L. Fredericks
Resource Operators Conference
Seismic Reflection surveys and borehole drilling have been the two primary exploration tools used in Illawarra Coal’s operations in the Southern Coalfield. For the past 10 years the exploration department has been using their in house acquisition system developed by BHP. However, this system was limited to 180 channels and two dimensional surveys and a more advanced system was required with a much larger channel capacity for modern three dimensional seismic surveys. In July 2004 Illawarra Coal acquired a more advanced seismic acquisition system from Vibtech in the UK, which enabled high resolution three dimensional surveys to be conducted. Acquisition, …
A Website On Coal And Gas Outburst Management, D. Vyas, N. Aziz, R. Caladine, L.Ucia Tome
A Website On Coal And Gas Outburst Management, D. Vyas, N. Aziz, R. Caladine, L.Ucia Tome
Resource Operators Conference
The University of Wollongong received funding from the Australian Coal Association Research Program (ACARP) in 2005 to develop a website on coal and gas outbursts in the Australian environment < www.uow.edu.au/outburst >. The primary objective of the website is to provide the coal mining industry with the information on outburst occurrence and mechanisms of outburst phenomenon and the means of treating it. The online system provides access to the experiences, knowledge and information acquired by the coal mining industry, research organisations and educational institutions in a quality controlled environment. Although the website is specific to the Australian scene, it nevertheless contains information …
An Investigation Into Underground Mine Interaction With Overlying Aquifers, Huntly East Mine, New Zealand, G. Guy, W. Gale, B. Sinclair, D. Fergusson, B. Farnworth
An Investigation Into Underground Mine Interaction With Overlying Aquifers, Huntly East Mine, New Zealand, G. Guy, W. Gale, B. Sinclair, D. Fergusson, B. Farnworth
Resource Operators Conference
In recent years, Huntly East Mine has operated at a depth range of approximately 100 m to 220 m below a Quaternary aged clay, sand and silt aquifer that is connected to a nearby large river system (Waikato River). A key issue for mine planning and environmental management has been the development of mine design criteria to allow efficient mining of the reserves and to maintain the integrity of the aquifer. A case study and back analysis at Huntly East Mine is presented, which investigates the overburden conductivity and the impacts caused by mining-induced caving. The case study includes: i. …
Developing Methods For Placing Sand-Propped Hydraulic Fractures For Gas Drainage In The Bulli Seam, K. Mills, R. Jeffrey, D. Black, T. Meyer, K. Carey, S. Goddard
Developing Methods For Placing Sand-Propped Hydraulic Fractures For Gas Drainage In The Bulli Seam, K. Mills, R. Jeffrey, D. Black, T. Meyer, K. Carey, S. Goddard
Resource Operators Conference
BHP Billiton Illawarra Coal is seeking ways to significantly increase gas capture rates from in seam drilling programs in its underground coal mining operations. Hydraulic Fracture Technology (HFT), a joint venture between SCT Operations Pty Ltd and CSIRO Petroleum, is working with Illawarra Coal to develop the capability to enhance gas drainage rates in the Bulli Seam using sand-propped hydraulic fracturing based on HFT’s experience at Dartbrook Mine where gas drainage rates were increased by 5 to 180 times. One of the principal challenges for implementing sand-propped hydraulic fracturing in the Bulli Seam is the high vertical stresses that cause …
Management Of Impacts Of Longwall Mining Under Urban Areas, D. Kay, A. Waddington, J. Page, B. De Somer
Management Of Impacts Of Longwall Mining Under Urban Areas, D. Kay, A. Waddington, J. Page, B. De Somer
Resource Operators Conference
Current and proposed expansions to existing underground coal mines are occurring in closer proximity to and directly beneath urban areas. The density of built infrastructure potentially impacted by longwall mining is substantially increased in urban areas when compared with mining beneath rural areas. Management of the impacts of longwall mining in such areas requires extensive consultation with the affected community, including education and management of communities’ expectations regarding what could be expected during and after the mining period. Approaches undertaken by Tahmoor Colliery to manage the potential impacts of mining under the township of Tahmoor are discussed. A summary of …
An Assessment Of Load Transfer Mechanism Using The Instrumented Bolts, H. Jalalifar, N. Aziz, Muhammad N S Hadi
An Assessment Of Load Transfer Mechanism Using The Instrumented Bolts, H. Jalalifar, N. Aziz, Muhammad N S Hadi
Resource Operators Conference
Load transfer capacity and failure mechanism of a fully grouted bolt installed across joint plane in shear is evaluated experimentally and numerically, tests were made on un-instrumented and strained gauge instrumented bolts. Four types of bolts, with different properties and surface configurations were selected for the study. The changes in strength of the concrete, bolt mechanical properties and bolt pretension load were evaluated in different shear environments. Results from the instrumented bolts and numerical simulation showed that the tensile and compression stresses and strains are generated at early stage of loading and hinge points are created at both sides of …
High-Resolution Topographic Data For Subsidence Impact Assessment And Smp Preparation: Methods And Considerations, Daniel R. Palamara, G. Brassington, Phil Flentje, Ernest Baafi
High-Resolution Topographic Data For Subsidence Impact Assessment And Smp Preparation: Methods And Considerations, Daniel R. Palamara, G. Brassington, Phil Flentje, Ernest Baafi
Resource Operators Conference
Corporate and social requirements relating to sustainable mining practices have resulted in an increasing need for identification and assessment of natural features that may be susceptible to coalmine-induced subsidence. Natural features such as, cliff lines, watercourses and steep slopes, that are typically susceptible to subsidence-induced impacts can often be identified and quantified using high-resolution topographic data and a geographic information system (GIS). Once identified, digital representations of these features can be used in the impact assessment process and for Subsidence Management Plan (SMP) preparation. This paper demonstrates the use of topographic data for site characterisation and feature identification purposes by …
A Case Study On Longwall Mining Under The Tidal Waters Of Lake Macquarie, G. Li, I. Forster, M. Fellowes, A. Myors
A Case Study On Longwall Mining Under The Tidal Waters Of Lake Macquarie, G. Li, I. Forster, M. Fellowes, A. Myors
Resource Operators Conference
This article presents a case study of longwall mining under the tidal waters of Lake Macquarie, south of Newcastle, NSW. The mining operation took place at the Wyee Colliery from 1998 to 2002, without any incidence of ingress of water from the lake. This paper describes i) the design strategy used for a viable and robust mine layout that minimises the risk of water ingress ii) observations made during the operational phase and iii) a practical tool for designing underground coal mines under surface water bodies.
Monitoring Of Subsidence Movements At Major Infrastructure, J. Barbato, D. Kay, H. Pinkster, B. De Somer
Monitoring Of Subsidence Movements At Major Infrastructure, J. Barbato, D. Kay, H. Pinkster, B. De Somer
Resource Operators Conference
Time based mine subsidence predictions provide a valuable tool, as part of an overall management strategy to protect infrastructure, which involves making subsidence predictions at set increments of longwall travel. The predictions can be presented as a series of subsidence contours or profiles, and can be animated to show the progression of the subsidence travelling wave. The observed movements at major items of infrastructure can then be compared to the predicted movements at any time throughout the mining period. The challenges in providing time based predictions are discussed. Two examples are provided: the Main Southern Railway at Tahmoor Colliery and …
Airborne And Terrestrial Laser Scanning - Applications For Illawarra Coal, P. Riley, P. Crowe
Airborne And Terrestrial Laser Scanning - Applications For Illawarra Coal, P. Riley, P. Crowe
Resource Operators Conference
Laser Scanning technology was introduced to the mapping industry in 1998. The technology enables the acquisition of point data by a laser scanning device mounted either in a fixed or rotary winged aircraft (Airborne, ALS) or placed on ground stations (Terrestrial, TLS). Laser scanning provides a significant increase in data points (e.g. 18 million data points can be gathered per hour) over traditional data capture methods. It also affords cost reductions due to acquisition and processing times when compared to aerial photogrammetry or ground surveying, particularly in areas that are densely vegetated or difficult to access. Due to the relatively …
Surface Goaf Hole Drainage Trials At Illawarra Coal, T. Meyer
Surface Goaf Hole Drainage Trials At Illawarra Coal, T. Meyer
Resource Operators Conference
Surface goaf gas extraction methods are successfully applied at a number of Australian and overseas underground coal mines. BHPB Illawarra Coal has recently undertaken a trial program to determine the effectiveness of surface goaf wells to reduce gas concentrations within the longwall ventilation circuit, and minimise gas related production delays. Three trial wells have been completed within the Bulli Seam operations. Considerable production variation between the three wells was recorded. A goaf gas reservoir model is discussed which describes a sequence of permeability changes within the different goaf strata, dictated by stress changes associated with caving, then recompaction. A requirement …
Impacts Of Longwall Mining To Rivers And Cliffs In The Southern Coalfield, D. Kay, J. Barbato, G. Brassington, B. De Somer
Impacts Of Longwall Mining To Rivers And Cliffs In The Southern Coalfield, D. Kay, J. Barbato, G. Brassington, B. De Somer
Resource Operators Conference
Extraction of coal using longwall mining techniques causes subsidence which has potential to affect surface features, including environmentally sensitive areas such as rivers and cliffs. There are currently a number of proposed extensions to coal mining operations in the Southern Coalfield of New South Wales that are seeking to mine close to rivers and cliffs. These proposals have attracted some community concern at a local and regional level. This concern is largely founded on impacts that have occurred as a result of previous mining activities, the majority of which occurred directly beneath the impacted sites. It was therefore considered a …
Development Of In-House Coal Seam Permeability Testing Capabilities, T. Cummins, L. Fredericks
Development Of In-House Coal Seam Permeability Testing Capabilities, T. Cummins, L. Fredericks
Resource Operators Conference
Coal seam gas has historically been and still remains a major issue for underground Illawarra Coal’s mining operations in the Southern Coalfield. The control of seam and strata gas is essential to maintaining operational safety and mining continuity. The Resource and Exploration department surface exploration drilling program is currently investigating coal seam gas characteristics through the use of coal permeability testing (injection fall-off testing). The need for coal permeability testing is essential for assessing the reservoir gas characteristics in the seams. Coal seam structure and reservoir properties are closely related to regional and localised geological structure, which greatly influence insitu …
Bolt Surface Configurations And Load Transfer Mechanism, N. Aziz, H. Jalaifar, J. Concalves
Bolt Surface Configurations And Load Transfer Mechanism, N. Aziz, H. Jalaifar, J. Concalves
Resource Operators Conference
A series of laboratory based push and pull tests were carried out to investigate how surface profile influence the load transfer mechanism of bolt/resin interface. Tests were carried out in both 75 mm and 150 mm long steel sleeves. Three types of bolts were examined, they were bolts most commonly used for strata reinforcements in underground coal mines in Australia. The bolts had near equal core diameter but of different profile configurations. The change in the length of the encapsulation sleeve was examined in light of the small number of profiles encapsulated effectively in short 75 mm long sleeves. The …
Sterilisation Of Coal Resources In The Southern Nsw Coalfields: The Cfmeu Perspective, G. White
Sterilisation Of Coal Resources In The Southern Nsw Coalfields: The Cfmeu Perspective, G. White
Resource Operators Conference
The Construction, Forestry, Mining and Energy Union covers workers in several major industries, including coal mining. It represents an amalgamation of many trade-based and industry unions. One of these was “the Miners’ Federation” (ACSEF - Australasian Coal and Shale Employees’ Federation) that was formed in 1915. Union history shows sporadic coal unionism – including southern New South Wales – dating back to the 1850s. Within the coal industry the CFMEU represents the overwhelming majority of production and maintenance workers – over 15,000 across Australia. As a result of a high level of unionisation, and a history of strong union campaigning, …
Ground Vibrations Arising From Using Two Types Of Explosives - A Comparative Study, S. M. Hossaini, Gour Sen
Ground Vibrations Arising From Using Two Types Of Explosives - A Comparative Study, S. M. Hossaini, Gour Sen
Resource Operators Conference
Results of an investigation into ground vibrations carried out in an open pit coal mine in New South Wales has been analysed. As this mine is located in a sensitive area in regard to potential damage from ground vibrations, severe restrictions were imposed on the blasting operations. In this study 44 sets of recorded experimental blast data have been analysed. Two valuable equations have evolved from the data when two types of explosives were used. A comparison between the effects of two explosive types, namely ANFO and slurry, on ground vibration is presented. It has been shown that the intensity …
Water Inflow Issues Above Longwall Panels, W. Gale
Water Inflow Issues Above Longwall Panels, W. Gale
Resource Operators Conference
The aim of this paper is to discuss the issues which relate to surface water inflow through the fractured overburden above longwall panels. The information used is a combination of field experience and computer modeling. Computer models used in this study simulate the fracture process in the geological units throughout the overburden. Analysis of the mining induced fracture patterns and in situ joint patterns allows an estimation of the hydraulic conductivity within the overburden. The cubic flow relationship has been used in examples presented.