检索结果-南通市图书馆

International Journal of Mining Science and Technology 2020年第1期30卷 49-54页

作者： bruce hebblewhite School of Minerals and Energy Resources Engineering University of New South WalesSydney 2052Australia

Historically there have been a number of different hypotheses and empirical models developed in an attempt to describe the nature of fracturing above longwall panels in underground coal mining.The motivation for suchmodels varies,ranging fromunderstanding the impact ofmining on surface subsidence,to back-analysis of caving behaviour in the immediate roof behind the longwall face.One of the most critical motivating factors that is taking on increased importance in many coalfields,is the need for better understanding,and hence prediction of the impact of mining on overlying strata,particularly strata units acting as aquifers for different groundwater horizons.This paper reviews some of the major prediction models in the context of observed behaviour of strata displacement and fracturing above longwall panels in the southern coalfields of New South Wales,south of Sydney.The paper discusses the parameter often referred to as"height of fracturing"in terms of the critical parameters that influence it,and the relevance and appropriateness of this terminology in the context of overlying sub-surface subsidence and groundwater impact.The paper proposes an alternative terminology for this parameter that better reflects what it is and how it is used.The paper also addresses the potential role of major bedding shear planes mobilised by mining and their potential influence on overlying subsidence and groundwater interference.

关键词： Longwall mining Subsidence Groundwater Caving Underground coal mining

Coal mine roof rating(CMRR),rock mass rating(RMR)and strata control:Carborough Downs Mine,Bowen Basin,Australia

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2020年第2期30卷 225-234页

作者： Martin Brook bruce hebblewhite Rudrajit Mitra School of Environment University of AucklandAuckland 1010New Zealand School of Mining Engineering University of New South WalesNSW 2052Australia School of Mining Engineering University of the WitwatersrandJohannesburg 2050South Africa

The rock mass rating(RMR)has been used across the geotechnical industry for half a century.In contrast,the coal mine roof rating(CMRR)was specifically introduced to underground coal mines two decades ago to link geological characterization with geotechnical risk mitigation.The premise of CMRR is that strength properties of mine roof rock are influenced by defects typical of coal measures stratigraphy.The CMRR has been used in longwall pillar design,roof support methods,and evaluation of extended cuts,but is rarely evaluated.Here,the RMR and CMRR are applied to a longwall coal mine.Roof rock mass classifications were undertaken at 67 locations across the mine.Both classifications showed marked spatial variability in terms of roof conditions.Normal and reverse faulting occur across the mine,and while no clear relationships exist between rock mass character and faulting,a central graben zone showed heterogeneous rock mass properties,and divergence between CMRR and RMR.Overall,the CMRR data fell within the broad envelope of results reported for extended cuts at Australian and U.S.coal mines.The corollary is that the CMRR is useful,and should not be used in isolation,but rather as a component of a strata control programme.

关键词： Rock mass classification Roof strength Coal mine CMRR RMR Bowen Basin

A semi-quantitative coal burst risk classification system

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2018年第5期28卷 721-727页

作者： Onur Vardar Chengguo Zhang Ismet Canbulat bruce hebblewhite School of Minerals and Energy Resources Engineering University of New South Wales

Safety is the highest priority in the mining industry as underground mining in particular poses high safety risks to its workers. In underground coal mines, coal bursts are one of the most catastrophic hazards, which involves sudden and violent dynamic coal mass failure with rapid ejection of the broken material into the mine workings. Despite decades of research, the contributing mechanisms of coal bursts are still not completely understood. Hence, it remains challenging to forecast coal bursts and quantify their likelihood of occurrence. However, a range of geological and geotechnical factors are associated with coal bursts and can increase the coal burst proneness. This paper introduces a semi-quantitative coal burst risk classification system, namely, BurstRisk. Based on back-analysis of case histories from Australia, China and the United States, BurstRisk classifies the coal burst risk into three categories:low, medium and high risk. In addition, it allows mining engineers to modify the weighting of the selected factors based on specific conditions. The risk classification charts introduced are for both longwall retreat and development sections of long-wall mining operations. This paper also provides a set of risk management strategies and control measures for effective coal burst mitigation.

关键词： Underground coal mining Coal burst Rockburst Risk management Safety Semi-quantitative

A review of cavability evaluation in longwall top coal caving

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2017年第6期27卷 907-915页

作者： Tien Dung Le Rudrajit Mitra Joung Oh bruce hebblewhite School of Mining Engineering The University of New South Wales Sydney NSW 2052 Australia

Longwall Top Coal Caving has been considered as one of the most effective technologies for the extraction of underground thick coal seams. A large number of studies on the applicability of Longwall Top Coal Caving into new mine sites have linked the success of its application to the geo mechanical understanding of the cavability of the top coal. The paper aims to improve the knowledge of the top coal cavability evaluation. A range of parameters that affect the top coal cavability were first identified. Afterward, a number of cavability assessment methods and classifications were reviewed. The result is important in that it assists researchers in developing an advanced and reliable tool for the top coal cavability evaluation.

关键词： Longwall top coal caving Cavability Numerical modelling Caving mechanism Caving classification

Numerical modelling of strength and energy release characteristics of pillar-scale coal mass

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2019年第5期11卷 935-943页

作者： Onur Vardar Chengguo Zhang Ismet Canbulat bruce hebblewhite School of Minerals and Energy Resources Engineering.University of New South Wales

Coal burst is a manifestation of rapid energy release,which is considered as one of the most critical operational hazards in underground coal mines.This study numerically investigates the effects of discontinuities on the strength and energy release characteristics of coal mass samples under uniaxial compression.The universal distinct element code(UDEC)was used to model pillar-scale coal mass samples that were represented by an assembly of triangular deformable blocks,and pre-existing discontinuities such as bedding planes and cleats were also included in the models.It shows that cleat spacing can have a significant impact on compressive strength and energy release,with both strength and energy release(magnitude and rate)reducing as the number of cleats was increased.This work is one of the first attempts to numerically model and quantify the energy release which occurs during the failure of pillar-scale coal mass samples with varying cleat densities.The insights from the numerical modelling can help to understand the possible energy release mechanisms and associated coal burst potential in changing coal cleat conditions.

关键词： Coal burst Coal cleating Energy release Distinct element method(DEM) Numerical modelling

Discussions on rockburst and dynamic ground support in deep mines

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2019年第5期11卷 1110-1118页

作者： Charlie C.Li Peter Mikula Brad Simser bruce hebblewhite William Joughin Xiaowei Feng Nuwen Xu Norwegian University of Science and Technology (NTNU) Trondheim Norway Mikula Geotechnics Pty. Ltd. Kalgoorlie Australia Glencore Company Sudbury Canada The University of New South Wales (UNSW) Sydney Australia SRK Consulting Johannesburg South Africa China University of Mining and Technology Xuzhou China Sichuan University Chengdu China

The paper is a summary of discussions on four topics in rockburst and dynamic ground support.Topic 1 is the mechanisms of rockburst.Rockburst events are classified into two categories in accordance with the triggering mechanisms,i.***.strain burst and fault-slip burst.Strain burst occurs on rock surfaces when the tangential stress exceeds the rock strength in hard and brittle rocks.Fault-slip burst is triggered by fault-slip induced seismicity.Topic 2 is prediction and forecasting of rockburst events.Prediction for a rockburst event must tell the location,timing and magnitude of the event.Forecasting could simply foresee the probability of some of the three parameters.It is extremely challenging to predict rockbursts and large seismic events with current knowledge and technologies,but forecasting is possible,for example the possible locations of strain burst in an underground opening.At present,the approach using seismic monitoring and numerical modelling is a promising forecasting method.Topic 3 is preconditioning methods.The current preconditioning methods are blasting,relief-hole drilling and hydrofracturing.Defusing fault-slip seismicity is difficult and challenging but has been achieved.In very deep locations(>3000 m),the fracturing could extend from the excavation face to a deep location ahead of the face and therefore preconditioning is usually not required.Topic 4 is dynamic ground support against rockburst.Dynamic ground support requires that the support system be strong enough to sustain the momentum of the ejecting rock on one hand and tough enough on the other hand to absorb the strain and seismic energies released from the rock mass.The current dynamic support systems in underground mining are composed of yielding tendons and flexible surface retaining elements like mesh/screen and straps.Yielding props and engineered timber props are also used for dynamic support.

关键词： Rockburst Seismic event Dynamic ground support Forecasting Preconditioning

A review of the geomechanics aspects of a double fatality coal burst at Austar Colliery in NSW,Australia in April 2014

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2017年第1期27卷 3-7页

作者： hebblewhite bruce Calvin Jim School of Mining Engineering UNSWSydney 2052Australia

A coal burst occurred on 15 April, 2014 at the Austar Coal Mine, located west of Newcastle, NSW,Australia. The burst resulted in fatal injuries to two men working as part of the mining crew at the development face. At the time, a continuous miner was being used to mine a longwall development gate road through heavily structured coal, at a depth of approximately 550 m. A number of pre-cursor bumps had occurred on previous shifts, emanating from the coal ribs of the roadway, in proximity to the coal face.This paper reviews the geological, geotechnical and mining conditions and circumstances leading up to the coal burst event; and presents and discusses the available evidence and possible interpretations relating to the geomechanical behaviour mechanisms that may have been critical factors in this incident. The paper also discusses some key technical and operational considerations of ground support systems and mining practices and strategies needed for operating in such conditions in the future.

关键词：新南威尔士地质力学澳大利亚煤矿病死审查工程地质条件突发事件

Assessment of energy release mechanisms contributing to coal burst

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2017年第1期27卷 43-47页

作者： Zhang Chengguo Canbulat Ismet Tahmasebinia Faham hebblewhite bruce School of Mining Engineering UNSW Sydney 2052Australia

Coal burst is a dynamic release of energy within the rock(or coal) mass leading to high velocity expulsion of the broken/failed material into mine openings. This phenomenon has been recognised as one of the most catastrophic failures associated with the coal mining industry, which can often lead to injuries and fatalities of miners as well as significant production losses. This paper aims to examine the mechanisms contributing to coal burst occurrence, with an emphasis on the energy release concept. In this study, a numerical modelling study has been conducted to evaluate the roles and contributions of difference energy components. The energy analysis presented in this paper can help to improve the understanding of energy release mechanisms especially under Australian conditions.

关键词：能量释放释放机制煤爆评价动态释放煤炭开采生产损失数值模拟