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Numerical Modelling On The Stability Of An Underground Research Facility Excavation In Czech Republic, Libin Gong, Petr Waclawik, Kamil Soucek, Martin Vavro, Jan Nemcik, Sahendra Ram, Radovan Kukutsch

Resource Operators Conference

ABSTRACT: A new Underground Research Facility (URF) is planned to be constructed in the Rožná Mine, Czech Republic. It is essential to evaluate the feasibility of the current excavation design before the start of the excavation. Numerical simulation using the software FLAC3D was adopted to investigate the stability or the strength-stress ratio of the URF. Laboratory tensile strength and uniaxial compressive strength tests on the rock specimens at various inclinations of the weak planes combined with the Geological Strength Index (GSI) system provide reliable deformation and strength input parameters for the explicit continuum model. The well-known modified Hoek-Brown constitutive model …

Improving Rock Mechanical Properties Estimation Using Machine Learning, Ruizhi Zhong, Matt Tsang, Gift Makusha, Ben Yang, Zhongwei Chen

Resource Operators Conference

ABSTRACT: Rock mechanical properties (e.g., uniaxial compressive strength or UCS, Young’s modulus, and Poisson’s ratio) are important input parameters for geotechnical assessment and excavation designs. Two common methods used to obtain these parameters are laboratory testing and geophysical logging. The former delivers probably the most reliable results, but can be costly and time-consuming and for a lot of the time it is challenging to source sufficient samples. Alternative ways to better predict rock mechanical properties are needed.

In this case study, the XGBoost machine learning algorithm was applied to correlate laboratory and geophysical logging data with the three mechanaical properties …

The Changes And Future Of Australian's Resources Sector And The Advancements The Industry Has Made In Relation To Safety, Ian Macfarlane

Resource Operators Conference

No abstract provided.

Angled Shear Testing Of 15.2 Mm Seven Wire Cable Bolt, Naj Aziz, Sina Anzanpour, Saman Khaleghparat, Ashkan Rastegarmanesh, Ali Mirzaghorbanali, Alex Remmenikov, Jan Nemcik, Joung Oh, Guangyao Si

Resource Operators Conference

ABSTRACT: This paper focuses on the experimental study of shear testing of 15.2 mm, 25 t capacity seven wire cables at zero, 30 and 45 degree angles using two different shear testing facilities at the University of Wollongong (UOW) and the University of Southern Queensland (USQ) in Toowoomba. A circular double shear rig MKIV was used for testing cable perpendicular to the sheared joint faces (zero angle of orientation), while testing the cable at 30 and 45 degrees was carried out using a larger size rectangular shaped rig. This study was part of the tri-universities funded ACARP project C27040 awarded …

Respirable Coal Dust And Silica Exposure Standards In Coal Mining: Science Or Black Magic?, Nikky Labranche, David Cliff, Kelly Johnstone, Carmel Bofinger

Resource Operators Conference

ABSTRACT: The re-identification of mine dust lung diseases in coal mine workers has prompted much work to be done to improve exposure monitoring and health surveillance in Australia. It is now recognised to be inadequate to talk about respirable dust in general terms, because size, shape and chemical content can affect the adverse consequences of excessive exposure. The Minerals Industry Safety and Health Centre within the Sustainable Minerals Institute undertook a gap analysis to identify needs for further research into respirable dust exposure monitoring and control. One such project is characterising the dust present in different mining atmospheres to understand …

A Case Of Longwall Coal Mining Productivity & Safety Optimisation, Sahar Ardehali, Naj Aziz, Habib Alehossein, Matthew Bowerman, Matt Robbins

Resource Operators Conference

ABSTRACT: This paper presents a study, the design and implementation of the Longwall Remote Operations centre that incorporates all aspects of automation for Longwall and coal clearance systems.

Developing the existing Longwall technology strategy and the design of coal transferring conveyors to smart systems incorporating emerging technologies such as artificial intelligence, automation and business strategy development.

The design phase of the project is structured to bring together the overall findings of the diagnose phase, business strategic direction, value case and options analysis to develop an overall project that covers people, technology, systems and process for the automated control of the …

Using Remote Reading Instrumentation To Improve Safety, Productivity, And Support Design In Underground Coal Mines, Samantha Watson, Nathan Owen, Claire Morton

Resource Operators Conference

ABSTRACT: Accurate and timely monitoring of strata stability in underground excavations is a critical activity that forms part of the fundamental daily mine safety processes and is mandated by law to be carried out in all operations. Coal mine strata monitoring includes the use of instrumentation and observations carried out by personnel. Mechanical tell-tales are an instrument widely used throughout the coal mining industry and are used to measure displacement of roof rock horizons. They comprise of either 2 or 4 reading indicators that are connected by stainless steel wires to anchors secured up a purposely drilled hole and require …

A First-Principles Causation Hypothesis For Pillar Bursts In Underground Coal Mines, Russell Frith

Resource Operators Conference

ABSTRACT: A review of published literature reveals case histories whereby the entire periphery of a coal pillar has “burst” out as a single event during first workings, the associated energy and material release causing significant damage to adjacent roadways and any equipment/infrastructure located within said roadways. Such events are distinct from coal burst events during first workings such as that at the Austar Mine in 2014, or those linked to overburden bumps related to either horizontal stress-driven slip along major faults and/or thick, massive strata units in the overburden or floor of the coal seam. The paper considers as to …

Backfill Grouting For Mining Subsidence Prevention, Habib Alehossein, Baotang Shen, Zongyi Qin

Resource Operators Conference

ABSTRACT: Mining subsidence has been a major hazard in most underground coal mines, particularly those where designs and practices are based on the wrong assumption of fixed, permanent and nondeteriorating coal pillars. Mining induced subsidence significantly affects mining costs where major surface structures and natural environment need to be protected. Remedial measures to manage damage caused by subsidence can often be very costly with potentially damaging impacts and irreversible consequences. Backfilling and injection of granular materials into the mining induced voids, separated beddings and cracks, as either diluted granular slurry or concrete paste, is widely used to control mine subsidence …

Why Slender Beam/Column Behaviour Should Not Be Ignored For Effective Ground Support Design., Mark Colwell, Russell Frith

Resource Operators Conference

ABSTRACT: As per most other earth science engineering problems, the underground coal geotechnical environment and the way in which roof and rib support interacts with the rock mass are complex issues. It is therefore generally recognised that without prudent simplification, the complexity of the problem will overwhelm all current geotechnical methods of modelling, not least for the reason that a rock mass can never be characterised to a level that allows a “non-simplified” analysis. The fact that numerical models, which are commonly purported to be a “simulation” tool and the so-called epitome of advanced geotechnical engineering, always need to be …

Pretension Effect On The Performance Of Cable Bolts In Underground Coal Mines, Xu Li, Guangyao Si, Joung Oh, Zizhuo Xiang, Naj Aziz, Ali Mirzaghorbanali

Resource Operators Conference

ABSTRACT: Pretension plays a critical role in providing active support to control roof sagging and bedding plane slippage in underground coal mines. However, the optimal amount of pretension for cable bolts to achieve effective ground control remains unknown. Applying excessive pretension on cable bolts may cause cable bolt failure. On the other hand, insufficient pretension is ineffective in preventing large roadway deformation and roof fall incidents. This paper investigates the pretension effect on cable bolts at various geological conditions for underground coal mines. A numerical model based on a coal mine in the Western Coalfield, NSW has been developed by …

Laboratory And Field Testing Of Surfactants Used To Meet New Workplace Exposure Standards For Respirable Dust In Coal Mines, Neil Alston, Ping Chang, Zidong Zhao, Apurna Ghosh

Resource Operators Conference

ABSTRACT: Respirable coal dust is generated during the mechanised mining process and is one of the main occupational health hazards in coal mines. Due to its fine characteristics, it can affect the performance of mining equipment and cause adverse health effects in mine workers. There is a recent focus upon improved dust control measures in Australian mines. This is primarily due to a resurgence in reported cases of coal mine lung dust disease in both NSW and QLD coal mines. New more stringent workplace exposure standards (WES) are currently being introduced for both respirable coal and silica dusts. Considerable research …

Proceedings Of The 2021 Resource Operators Conference, Naj Aziz, Ali Mirzaghorbanali

Resource Operators Conference

Proceedings of the 2021 Resource Operators Conference. All papers in these proceedings are peer reviewed. ISBN (ebook): 978-1-74128-336-5 ISBN (paperback): 978-1-74128-335-8.

Fracture Propagation Mode Of Coal Under Indirect Tensile Stresses, Mehdi Serati, Hamid Roshan, Ali Mirzaghorbanali, Mutaz El-Amin Mahmoud, Thejaswee Valluru

Resource Operators Conference

ABSTRACT: This work presents the results of an investigation on the study of fracture pattern in coal under induced tensile stresses using image processing techniques. Several high-speed recordings captured at 5 kHz and above were examined, and three distinct fracture propagation modes were identified. As the coal tensile strength increases, the fracture behaviour was observed to be a spalling-like rupture in the form of a dominant tensile crack accompanied with multiple large secondary shear fractures that break the test specimen apart into several pieces. Combined localised tensile and shear cracks at intact rock bridges within a coal Brazilian sample (with …

Effect Of Surface Profile On Axial Load Transfer Mechanism Of Tendons, Ashkan Rastegarmanesh, Joel Misa, Ali Mirzaghorbanali, Naj Aziz, Kevin Mcdougall

Resource Operators Conference

ABSTRACT: Cable bolts as one of the most common means of ground support in surface and underground projects are attracting more attention due to their advantages over more expensive and cumbersome support elements. Thus, newer cables with new configurations and surface properties are emerging on a regular basis. Conventionally, the performance of cable bolts is studied in two main categories of axial and shear load transfer mechanisms. This paper focuses on the former by developing and proposing an experimental plan to cast light on the effect of surface profile on axial performance of cable bolts. Consequently, 15 representative surface profiles …

Mining Equipment Human Factors Design For Workforce Diversity, Danellie Lynas, Gary Dennis, Robin Burgess-Limerick

Resource Operators Conference

ABSTRACT: The minerals industry is a complex system in which procedures, equipment and people need to interact safely and efficiently to achieve operational requirements. The sector is also an attractive employment option, creating an environment of significant workforce diversity within equipment operators and maintainers. While a variety of standards and guidance materials exist to assist designers to provide equipment that accommodates workplace diversity, designers face significant challenges in applying this information, and may unnecessarily restrict the range of potential employees who can operate and maintain this equipment, and in turn create elevated injury risk. Understanding how equipment design impacts safe …

Hydrogeological Properties And Mining Impacts On Groundwater In The Bowen, Styx And Galilee Basins, George Klenowski, John Bernal

Resource Operators Conference

ABSTRACT: The results of extensive hydrogeological investigations in the Bowen, Styx and Galilee Basins are described in this paper. These are coal mining areas with saline groundwater resulting from predominantly marine deposition. Small aquifers occur in Quaternary and Tertiary deposits and within coal measures strata. Tertiary Basalt flows sometimes contain larger aquifers. Mining results in localised groundwater drawdown. Testing has included determination of in situ permeability, pump-out flow rates, salinity and pH values of groundwater. Piezometer monitoring of aquifer drawdown during mining has been completed. Computer modelling and inflow calculations have been used to determine inflow rates during longwall mining. …

The Fundamentals Of Modern Ground Control Management In Australian Underground Coal Mines, Jason Emery, Ismet Canbulat, Chengguo Zhang

Resource Operators Conference

ABSTRACT: Underground coal mining is inherently hazardous, with uncontrolled ground failure regarded as one of only several critical risks for multiple fatality events. Development, implementation and management of overarching systems and procedures for maintaining strata control is an important step in mitigating the impact of ground failure hazards at a mine site operational level. This paper summarises the typical Proactive Ground Control Management System (PGCMS) implemented in various Australian underground coal mines. Australia produces approximately 100 million tonnes a year of metallurgical and thermal coal from approximately 30 of the world’s safest longwall mines operating in New South Wales and …

Thin Spray-On Liners: A Historical Overview And Their Future Potential As Support In Underground Coal Mines, Claire Morton, Zhongwei Chen, Mehmet Siddik Kizil

Resource Operators Conference

ABSTRACT: Thin Spray-on Liner (TSL) is a fast setting, multi-component, polymeric material that is designed to be spray applied to a rock surface and provide areal support. TSLs are widely used in hard rock mining and some civil applications; however, they are yet to become a preferred support element in coal mining operations. Understanding of how TSL products behave to provide support to a coal rock mass and how they can be tested and monitored in-situ, is not well enough understood for them to be included as a routine support system. This presents a current challenge to the industry as …

Developing An Innovative Protective Structure On Continuous Miners Against Coal Burst Hazards, Ting Ren, Alex Remennikov, Xiaohan Yang, Dulara Kalubadanage, Peter Holt

Resource Operators Conference

ABSTRACT: As mining progresses into deep ore deposits in Australia, geo-hazards such as coal burst and outbursts are becoming a major concern for mine workers. The occurrence of these hazards involved the ejection of coal lumps and sometimes large volumes of hazardous gases such as methane and carbon dioxide. Whilst it is extremely important to de-stress and de-gas the seam and adjacent strata before roadway development, and install competent support systems such as steel mesh and bolt, the last line of protection will be the installation of a protective canopy on the Continuous Miner to shield mine workers from these …

Goaf Gas Distribution Near The Tailgate Under Three Gateroad Conditions, Rao Balusu, Bharath Belle, Krishna Tanguturi

Resource Operators Conference

ABSTRACT: A collaborative project was undertaken to obtain an understanding of the goaf gas distribution profile near the tailgate area of the longwall goaf under 2 gateroad and 3 gateroad mining conditions for improved explosion risk management in gassy mines. Extensive computational fluid dynamics (CFD) modelling studies were conducted and calibrated using operational longwall goaf gas distribution data. The results of the simulations indicated that there is a significant difference in the spread of explosive fringe (or close to explosive range) gas distribution profiles near the tailgate side of the longwall goaf under 2 gateroad and 3 gateroad conditions, i.e. …

Active Roadway Explosion Barrier Evolution In Coal Mining, Arend Späth, Bharath Belle

Resource Operators Conference

ABSTRACT: Methane gas and coal dust are an ever-present source of risk during underground coal mining operation. Methane gas and coal dust can create a combustible atmosphere. Adding a high enough energy source might ignite this combustible atmosphere and lead to an explosion. The prevention of methane gas and coal dust accumulation during mechanised cutting and crushing has evolved to an extent that might be accepted as a state of safe mining. Historic events suggest that methane gas ignitions can occur despite a general preventative practise being in place. Active explosion barriers are considered a last resort once methane gas …

Coastal Reservoir-A Technology To Supply Sufficient, High-Quality And Affordable Water To Industry With Minimum Environmental/Social Impact, Shu-Qing Yang

Resource Operators Conference

ABSTRACT: This paper discusses how to supply sufficient water to meet industrial water demand. Australia is not running out of water, but water is running out of Australia’s rivers. About 440km3/year of runoff is lost to the sea, and the total water usage is only about 5-6% of the water availability. Australia is one of the most resourceful countries in the world. All industrial water for the coastal areas can be supplied from coastal reservoirs, even the high-quality cooling water for steel making. To supply sufficient water to inland areas, the author has suggested that the Murray-Darling basin’s cotton farms …

Water Tracer Technologies To Detect Sources Of Seepage And Protect Environmental Assets, Wendy Timms, Devmi Kurukulasuriya, Bill Howcroft, Ellen Moon, Karina Meredith

Resource Operators Conference

ABSTRACT: Water tracer technologies can help optimise water management in coal mining operations and improve outcomes from environmental studies and controls to protect sensitive assets. ACARP project C28024 (Stage 1) is demonstrating how tracer analysis of groundwater and surface water can provide information on whether systems are hydrologically disconnected, partly connected or well connected. This stage of the project is focusing on conventional tracers that are often used by other mining industries around the world (e.g. iron ore, potash) and in groundwater resource studies. Stage 2 of this project proposes to test new artificial tracers combined with suitable conventional tracers …

Dynamic Model Of Fault Slip And Its Effect On Coal Bursts In Deep Mines, Jan Nemcik, Gaetano Venticinque, Zhenjun Shan, Libin Gong

Resource Operators Conference

ABSTRACT: The success of deep mining operations relies upon controlling the fractured ground. It is a documented knowledge that many coal bursts occur when mining close to the existing faults. Gradual stress relief towards excavations and other mechanisms can unload stress normal to the nearby fault plane causing it to slip. The generated seismic waves impact the mine roadway rib sides and can produce a coal burst. As part of the ACARP project, the FLAC3D dynamic numerical model was used to show how a fault slip at various locations and orientations may initiate a coal burst. This study simulates an …

Benchmarking Study By Laboratory Load Transfer Testing Along Full Resin Encapsulated Rock Bolts, Sabitha Sasi, Peter Craig

Resource Operators Conference

ABSTRACT: The primary ground support used in Australian underground coal mines is a rebar rock bolt anchored to the rock mass using polyester resin capsules. The key objective of this research project was to benchmark different types of Australian rockbolt resin capsules, including relatively new formulations. Laboratory test methods were developed based on previous studies conducted in South Africa and subsequently at the University of Wollongong, which used 1.8 m JX bolts for installation in internally threaded steel pipes that simulated the borehole. The encapsulated bolts were cut into 80 mm long sections for push testing to obtain around 20 …

Effect Of Pretension On The Mechanical Behaviour Of Bolted Rock, Mahdi Saadat, Abbas Taheri

Resource Operators Conference

ABSTRACT: A stepwise pull-and-shear test (SPST) scheme that numerically analyses the mechanical behaviour of bolted rock joints subjected to simultaneous pull-shear loading. The SPST scheme allows us to identify the optimum pretension stress magnitude at which the bolting system exhibits its ultimate shear capacity. The micro-mechanical properties of grout and bolt-grout interface were calibrated against the laboratory data. The micro-mechanical parameters of rock were calibrated against the laboratory data of coal and shale, and the micro-mechanical properties of rock joint interface were identified by reproducing the laboratory behaviour of coal-shale interface under the direct shear test. Then, the SPST scheme …

Introduction To New Methods Of Static And Dynamic Pull Testing Of Rock Bolts And Cable Bolts, Sina Anzanpour, Naj Aziz, Jan Memcik, Ali Mirzaghorbanali, Jordan Wallace, Travis Marshall, Saman Khaleghparast

Resource Operators Conference

ABSTRACT: Despite the decades where application of rock bolts and tendons have been the main supporting system for ground in both hard and soft rock formations in mines and tunnels, there remains significant uncertainty about the behaviour and performance of these easy-to-use technologies. The importance of effective support is paramount with regard to ground seismicity and dynamic loading cause by outburst, rock burst and rock blasting activities. The evaluation and assessment of the axial loading and shear behaviour of rock bolts enables the design of a credible methodology for effective and sound ground reinforcement. This paper deals mainly with the …

Numerical Approach Towards Dynamic Double Shear Testing Of Tendons Using Ls-Dyna, Saman Khaleghparast, Alex Remennikov, Naj Aziz

Resource Operators Conference

ABSTRACT: Underground support systems using tendons has been one of the significant achievements in Civil and Mining engineering endeavors in facing the challenges of ground control. However, shear failure of rock bolts is a concern in underground excavations particularly with respect to seismic events. The understanding of the performance of rock bolts under dynamic loading condition requires a great deal of research. A series of tests were undertaken utilising a drop hammer mass of 592 kg dropped from a maximum height of 2 m onto grouted rock bolts encapsulated in concrete blocks in the double shear box to investigate the …

Determining Rock Elastic Parameters Using A New True-Triaxial-Based Technique, Robert Purser, Mytaz El-Amin Mohmoud, Mehdi Serati, Zhongwei Chen

Resource Operators Conference

ABSTRACT: Rock elastic parameters (e.g., elastic modulus and Poisson’s ratio) are the most critical design features in geotechnical engineering since intact and rock masses generally respond in an elastic fashion up to the yield point when under complex three-dimensional stress-strain states. For instance, when a low-porosity rock is subjected to a uniaxial loading condition, it responds elastically up to the Crack Initiation (CI) point which is defined as the onset of stress-induced damage after the closure of pre-existing cracks. The CI stress level can then be used as an estimate for designing a rock structure against in-situ spalling if the …