Engineering Commons^™

2002 Safety Belt Usage Survey In Kentucky, Kenneth R. Agent, Eric R. Green

Kentucky Transportation Center Research Report

The objective of this study was to establish 2002 safety belt and child safety seat usage rates in Kentucky. The 2002 survey continues to document the results after enactment of a statewide mandatory safety belt law in 1994. Data were collected at 200 randomly selected sites spread across Kentucky. Data from the individual sites were combined into a statewide percentage considering function classification, geographic region, and vehicle miles traveled.

The data show that the usage rate in 2002 (62.0) was almost identical to that for 2001 (61.9). This compared to 60 percent in 2000, 59 percent in 1999, 54 percent …

Use Of Booster Fan Ventilation At West Cliff Colliery, D. Benson

Resource Operators Conference

Large underground coal mining operations, such as West Cliff are continually having to balance and co-ordinate ventilation requirements for each working face, with the overall management of gas both CO2 and CH4 within the mine. As mining operations expand, along with areas of goaf the potential for gas make increases. It becomes increasingly more difficult to maintain adequate ventilation to the development panels with corresponding effects or consequences on coal production.

Current In-Seam Drilling Techniques, J. Hanes

Resource Operators Conference

In-seam drilling has two main purposes: gas drainage and exploration. Each hole can yield information on the geological structure of the ground drilled, but in the drilling of some gas drainage holes, valuable geological data is lost. Drilling technology has changed in some ways over the last ten years, but still has some way to go. There is room for more improvements to reduce the costs, to reduce the risks and to increase the information gathered.

Overview Of Gas Outbursts And Unusual Emissions, R. Lama, A. Saghafi

Resource Operators Conference

Gas and rock outbursts are unwanted complications of underground coal mining, which have occurred over the last 150 years of underground coal mining worldwide and are still occurring. ‘Outburst’ is a dynamic phenomenon that causes the sudden concurrent release of gas and strata energy. The released energy causes pulverization of large amounts of coal and rocks, which are then ejected into the working areas during mining of the outburst prone zone. This paper discusses some of the 30,000 outburst events recorded worldwide and suggests indices to identify the outburst zones as well as methods of management of outbursts. The conclusions …

The Development Of Hazard Plans At Kestrel Mine, N. Gordon

Resource Operators Conference

Kestrel Mine is currently longwalling in the 2.4-3.3 metre thick German Creek seam, at depths between 220 and 295 metres. Run of mine production for the year 2002 is budgeted at 5.3mt, ramping up to 6mt by 2004. Achieving these levels of production will require a thorough understanding of the geological and geotechnical environment. The identification of potential hazards prior to intersection, is vitally important to ensure a consistent coal flow, free of major disruptions and downtime. Hence the preparation of development and longwall panel hazard plans, is an integral part of the production process. Emphasis is on the compilation …

History Of Outbursts In Australia And Current Management Controls, C. Harvey

Resource Operators Conference

Outbursts have been recognized as an inherent, world wide mining related phenomenon since the 1850’s. The level of understanding has grown and developed as Mining Engineers and Geologists have been able to gain more understanding of coal seam characteristics and measure or test various coal or seam parameters such as seam gas content, seam gas pressure, coal strength and depth of cover. This paper outlines some of the concepts associated with understanding the factors, which contribute to outbursts and details more specifically the nature of outbursts experienced in Australia, especially for the Bulli Coal Seam. A number of key outburst …

Gas Content Testing For Outburst Management Compliance, R. Williams

Resource Operators Conference

It is fundamentally important to make sure that compliance for mining is not issued on the basis of gas content tests that are inadequately located, deficient in frequency or in error. This paper covers some of the issues in relation to location and frequency of cores and validation of gas content test results. Core locations are discussed in the context of recent findings on the reduction of gas drainage efficiency towards the end of in-seam, cross panel boreholes. Some guidelines for sample frequency are given, with increased frequency being required in circumstances involving departure from “normal” conditions as defined through …

Case Study Central Colliery Qld, D. Bruggemann

Resource Operators Conference

A coal mine outburst occurred on the 20th of July 2001, in ‘B’ heading of 310 panel. It is the first such incident to have occurred at the mine in its 17 year history. Mining has since the initial days progressed to deeper levels where now the workings are at some 425m below the surface. The issue of greater gas contents with depth is recognised where inseam cross block drainage hole patterns are employed to drain and therefore reduce gas levels in the developing panels and in the longwall. The outburst incident was intimately related with a geological structure, which …

Case Study Management Of Outburst Risk At Tahmoor Colliery, P. Wynne

Resource Operators Conference

Tahmoor Colliery mines the Bulli Seam at a depth of 400-440m and has had to manage the risk of outbursts since it commenced production in the early 1980’s. Of necessity, it has been at the forefront of the development of systems to reduce outburst risks and has made many significant contributions to the industry in this regard. In the 1980’s, the general strategy for addressing these risks was that outbursts were “inevitable” and so most effort went into protection against their consequences. By the 1990’s, this approach was no longer acceptable and there was a major redirection of effort towards …

Assessment Of Rib Instability Hazards For Strata Management Systems, J. Shepherd

Resource Operators Conference

The support and control of unstable coal mine ribs is an on-going problem for the industry but in actual fact systematic research investigations were started almost 20 years ago in Australian Coal Industries Research Laboratory (ACIRL). This came about through the interests of the Australian Coal Association and the Queensland Coal Association Thick Seam Mining Committee. Some work was also carried out on coal mine rib mechanics under the NERDDC program in the mid 1980’s. Several collieries were directly experiencing fairly acute rib control problems at this time and the research work was linked with these. A number of publications …

Investigations Aimed To Improve Tailgate Serviceability At Dartbrook Mine, G. Tarrant, R. Doyle, K. Mills

Resource Operators Conference

Dartbrook Mine has experienced rib control difficulties because of deterioration in the tailgate corner of the longwall face as overburden depth has increased. This paper summarises an investigation to optimise support and develop strategies to improve the serviceability of the tailgate roadways. Field measurements undertaken in the tailgate of Longwall 6 identified roadway softening mechanisms, deformation characteristics and factors controlling deformation. This provides the basis for optimising the reinforcement system as part of an ongoing Strata Management Plan at the mine.

Geological Structures In Relation To Outburst Events, R. Doyle

Resource Operators Conference

In Australia irrespective of coal seam or coalfield, geological structures play a crucial role in the experience of having Instantaneous Outbursts. Identification of geological structures through concerted exploration activities, including drilling and remote techniques, or through the observations of both operators and geological personnel can allow for hazards to be identified and for precautionary measures to be implemented. This paper reviews; geological structures known to be associated with outbursts, some techniques used in the definition of such structures, and touches on the current procedures in place at mines that experience outburst phenomena or are concerned about such risks.

Outburst Research, M. Wold

Resource Operators Conference

The two books published by Dr. Ripu Lama (1995) and Dr. Lama and Dr. Jakob Bodziony (1996) are outstanding collections of literature, observations and original work in the field of gas outburst research and management. They provide a very solid base for further effort and developments; but they also serve to indicate that the problem is one of extreme complexity for which no ‘silver bullet’ solution is likely to be found. Since 1996, research has continued in several locations in Australia and overseas, generally stimulated by outburst events, or the perceived risk of occurrence in new areas or as mines …

Hydraulic Fracturing Applied To Stimulation Of Gas Drainage From Coal, R. Jeffrey

Resource Operators Conference

Hydraulic fracturing is routinely applied to stimulation of oil, gas, and coalbed methane wells around the world. The stimulation effect is achieved in coal seams as in other reservoirs, by producing a conductive fracture, connecting the well to the coal reservoir. The conductivity of the fracture is usually maintained by placing a round and sieved sand proppant in the fracture channel. The proppant prevents the fracture faces from closing back completely on one another after the treatment. The design of the fracture treatment, therefore, centers on selecting fluids, injection rates, and slurry concentrations that will produce the desired propped fracture …

Case Study Outburst & Gas Management, P. Eade

Resource Operators Conference

Illawarra Coal is part of Carbon Steel Materials that is in turn part of the BHP Billiton organization. Illawarra Coal operates five underground coal mines, viz Appin, Tower, West Cliff, Cordeaux and Elouera. One of these mines is Cordeaux Mine which ceased production in April 2001 and is currently being operated on a care and maintenance basis until its ultimate future is decided. Approval for a new mine, Dendrobium, has been granted and construction has commenced with the aim of replacing dwindling Elouera Mine production and reserves by 2004. Appin, Tower and West Cliff mine from the Bulli or No. …

Gas Drainage Experience At The North Goonyella Mine, P. Allonby

Resource Operators Conference

The North Goonyella Coal Mine has been owned in Joint Venture by RAG Australia Coal and Thiess NG Pty Ltd since November 2000. The mine is operated under contract by Thiess. Effective gas drainage is a fundamental requirement for the safe and efficient operation of the mine. Drainage has been effective since 1999 and with access to Australian and German knowledge, techniques will continuously be improved to enable the mine to economically mine deeper and gasier reserves without compromise in the safety of the mine and its people.

Strata Management In Weak Roof Conditions At Crinum Mine, D. Payne, B. Ward

Resource Operators Conference

Crinum Mine is located in the Bowen Basin and is operated by BM Alliance Pty Ltd. Longwall extraction commenced in 1997 in the 3.4m thick Lilyvale Seam and seven panels have been mined to date in the current block. The roof strata are variable and include some of the weakest longwall mining conditions in Australia. The immediate roof is predominantly a 15 to 25 MPa thinly bedded sandstone but includes weaker siltstone layers, typically 1m to 2m thick, with an average strength of 10 MPa. In some parts of the mining area the whole of the immediate roof appears to …

Strata Control In Underground Coal Mines: A Risk Management Perspective, C. Allanson

Resource Operators Conference

Hawcroft Miller Swan (HMS) reviews approximately 120 mines per year, around the world. Of these approximately 60% mine coal and the remainder metal and other minerals. Also approximately 60% of these mine underground. From our experience it is apparent that the mines with a well-developed understanding of their risk profile and a systematic approach to the way they do business, enjoy better business outcomes in terms of safety, productivity, cost control, profitability and reputation. Others without systems in place, consume a phenomenal amount of time and energy dealing with day-to-day issues, without ever gaining effective control of the critical issues …

Use Of Cone Bolts In Ground Prone To Rockburst, R. Mckenzie

Resource Operators Conference

Big Bell Mine started using the Cone bolt as a yieldable support to combat rockburst in September 1999. Australia has little experience of mining in rockburst conditions which makes the ground support requirements a new experience to all involved. Much work went into the design of the support patterns and the sequence of operations. The workforce required training in installation procedures, the theory behind yielding support and in the importance of good quality installation practices. Testing has been carried out on various grout mixes to determine the best mix for optimum bolt performance. This paper gives an overview of the …

A New Technique To Determine The Load Transfer Capacity Of Resin Anchored Bolts, N. Aziz

Resource Operators Conference

This paper describes a new technique to evaluate the load transfer capacity of different resin anchored rock bolts. With an increasing number of rock bolts currently being introduced into the Australian market for use in a variety of ground conditions, a new technique to determine bolt load transfer capacity is necessary. The assessment of the performance bolt with regard to load transfer mechanisms is conducted in the laboratory under Constant Normal Stiffness (CNS) conditions. This method of testing is considered as being a realistic way of evaluating bolt surface roughness as the tests are carried out under different confining pressures …

Gibsons Colliery - Thin Seam And Ultra Close Mining, K. Singer

Resource Operators Conference

Thin Seam Mining Pty Ltd (TSM) is contracted by Allied Coal Pty Ltd (Allied) to mine the Balgownie Seam at Gibson’s Colliery, Russell Vale. TSM will utilise place change systems of work as practiced in West Virginia, USA. For that purpose TSM has imported purpose-built, low-profile mining equipment from the USA. The equipment has been retrofitted in Wollongong with electrical systems that comply with Australian Standards. Presently the TSM workforce consists of approximately 14 operators from West Virginia, and 14 from Australia. There is more coal mined in the state of West Virginia than in Australia. Most of that coal …

Industry Impacts Outburst And Gas Management, B. Allan

Resource Operators Conference

Outbursts of gas, coal and rock are not a new phenomenon and have seriously impacted the safety of men and equipment within mines and the ultimate viability of the operations. Operational and management techniques have been applied to mines in the Illawarra as a means of working with outburst issues, but a complete understanding of the phenomenon at the different mines and locations is still lacking. Over the years specialists have championed the studies and investigations and significant advancements have been made in the safety of the mines. Extraction of quality reserves in otherwise unmineable domains has been made possible. …