آخرین محصولات
The Coal Mine Roof Rating (CMRR) A Practical Rock Mass ...
The Coal Mine Roof Rating System (CMRR) evaluates the structural competence of mine roof using simple field tests and observations obtained from underground exposures in roof falls or overcasts. The basis of the WRR is a weighing system which converts descriptive geologic roof rock data to a numerical value, facilitating its use in engineering ...
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Development of a Pre-Driven Recovery Evaluation Program ...
2009 Coal Operators' Conference The AusIMM Illawarra Branch 26 12 – 13 February 2009 . Figure 4 - Installation of pumpable cribs (Peng, 2007) Effect of mining parameters on pre-driven recovery roadways . The mining parameters that were analysed included: • Floor strength • Depth of extraction • Coal mine roof rating (CMRR)
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Development and Application of the Coal Mine Roof Rating ...
DEVELOPMENT AND APPLICATION OF THE COAL MINE ROOF RATING (CMRR) By Christopher Mark, Ph.D., P.E., 1 and Gregory M. Molinda 2 Principal research mining engineer. 2. Research geologist. Pittsburgh Research Laboratory, National Institute for Occupa-tional Safety and Health, Pittsburgh, PA. ABSTRACT The Coal Mine Roof Rating (CMRR) was developed
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Evaluation of rock mass classification schemes: a case ...
The development of an accurate engineering geological model and adequate knowledge of spatial variation in rock mass conditions are important prerequisites for slope stability analyses, tunnel design, mine planning and risk management. Rock mass classification schemes such as Rock Mass Rating (RMR), Coal Mine Roof Rating (CMRR), Q-system and Roof Strength Index (RSI) have been used …
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Roof Screening for Underground Coal Mines: Recent …
It has also been suggested that the Coal Mine Roof Rating (CMRR) could be used as a guide when considering the use of roof screen. If the CMRR of the roof is below 35, installing roof screen could
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The Coal Mine Roof Rating (CMRR) A Practical Rock Mass ...
The U.S. Bureau of Mines has developed a rock mass classification system for coal mine roof control. The Coal Mine Roof Rating System (CMRR) evaluates the structural competence of mine roof using simple field tests and observations obtained …
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Developing a new model based on neuro-fuzzy system for ...
Mark C, Molinda GM, Barton TM (2002) New developments with the coal mine roof rating. In: Proceedings of the 21st international conference on ground control in mining. West ia University, Morgantoen, WV, pp 294–301. 9. Deb D (2003) Analysis of coal mine roof fall rate using fuzzy reasoning techniques. Int J Rock Mech Min 40:251–257
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Support technologies for deep and complex roadways in ...
Based on geological and mining characteristics, coal mine roadways under complex conditions were divided into five types, for each type the deformation and damage characteristics of rocks surrounding roadways were analyzed. The recent developments of roadway support technologies were introduced abroad, based on the experiences of supports for deep and complex roadways from …
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Application of CMRI-ISM RMR for Stability Analysis of ...
Roof bolt failures in the mine generally occur due to the poor identification of the weak rock layers and considered as a major concern for underground coal mines in terms of its productivity and safety. The triggering factor responsible for underground roof failure is the presence of weak bedding planes and various geological discontinuities. Geological disruptions present in the mine roof ...
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New Developments With The Coal Mine Roof Rating - CORE
New Developments With The Coal Mine Roof Rating . By . Abstract. The Coal Mine Roof Rating (CMRR) was first presented at this Conference nine years ago. Since its introduction, the CMRR has been incorporated into many aspects of mine planning, including longwall pillar design, roof support selection, feasibility studies, and extended cut ...
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Figure 3 from Application Of The Coal Mine Roof Rating ...
Since it was first introduced, the Coal Mine Roof Rating (CMRR) has been widely accepted as a tool for geologic characterization and mine planning. This paper discusses the application of the CMRR to another practical ground control problem. Extended cuts (cuts greater than 6 m (20 ft) in length) are commonly used with remote control continuous ...
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CDC - Mining - Application of the Coal Mine Roof Rating ...
Since it was first introduced, the Coal Mine Roof Rating (CMRR) has been widely accepted as a tool for geologic characterization and mine planning. This paper discusses the application of the CMRR to another practical ground control problem.
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Assessment of development roadway roof conditions at an ...
Stephen Giese, Jason Emery and Ismet Canbulat, Assessment of development roadway roof conditions at an operating underground coal mine using neural network analysis, in Naj Aziz and Bob Kininmonth (eds.), Proceedings of the 2019 Coal Operators Conference, Mining Engineering, University of Wollongong, 18-20 February 2019, 66-81.
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Christopher MARK | Principal Roof Control Specialist | PhD ...
From 1999 through 2008, groundfall events resulted in 75 fatalities, 5,941 injuries and 13,774 noninjury roof falls in U.S. underground coal mines, according to the U.S. Mine Safety and Health ...
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The sustainable development of coal mines by new cutting ...
sustainable development, coal mine, roof cutting, chain arm, retain roadway Author for correspondence: Yang Tai e-mail: cumtcqty@163 The sustainable development of coal mines by new cutting roof technology Bin Yu1, Yang Tai2, Rui Gao3, QiangLing Yao2, Zhao …
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Design of primary ground support during roadway ...
The term "successful" refers to those designs that were used on a repeated basis for the purpose of roadway development. The primary roof support database indicates that the major factors influencing successful roof support designs are roof competency, expressed as the coal mine roof rating (CMRR), and in situ stress.
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Rating the strength of coal mine roof rocks. Information ...
@article{osti_229310, title = {Rating the strength of coal mine roof rocks. Information circular/1996}, author = {Molinda, G M and Mark, C}, abstractNote = {The Ferm pictoral classification of coal measure rocks is widely utilized in coalfield exploration. Although extremely useful as an alternative to conventional geologic description, no material properties are provided that would be ...
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Surface Subsidence Due to the Combined Effects ... - OneMine
New developments with the coal mine roof rating Application of geotechnical and geophysical parameters to im Development of a Risk Rating System for Use in Underground C Empirical and analytical design of large openings at a propo Shear Mechanism for Mining-Induced Fractures Applied to Rock Evaluating Techniques for Monitoring Rock Falls and ...
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A Case History Investigation of Two Coal Bumps in the ...
New developments with the coal mine roof rating Application of geotechnical and geophysical parameters to im Development of a Risk Rating System for Use in Underground C Empirical and analytical design of large openings at a propo Shear Mechanism for Mining-Induced Fractures Applied to Rock Evaluating Techniques for Monitoring Rock Falls and ...
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(PDF) Analysis of Coal Pillar Stability (ACPS): A New ...
Multiple-seam mining in the United States: An analysis of multiple seam stability in Northern Appalachian Coal Mines with minimal depth of cover and interburden Jan 2015 M J Castner
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Analysis of coal pillar stability (ACPS): A new generation ...
The coal mine roof rating (CMRR) rock mass classification was developed so that geologic factors could be quantified and integrated into the longwall pillar design process. Ultimately, a large database of case histories was collected during visits to longwall mines throughout the US, and modern multi-variate statistical techniques were used for ...
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NIOSH releases new coal mine roof rating software ...
The item NIOSH releases new coal mine roof rating software represents a specific, individual, material embodiment of a distinct intellectual or artistic creation found in Indiana State Library. This item is available to borrow from 1 library branch.
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Prediction of face advance rate and determination of the ...
A new approach for prediction of face advance rete (FAR) prior to mining operation and determination of the operation efficiency after mining operation in retreat longwall mining panel is presented based upon the concepts of rock engineering system (RES). For this purpose, six longwall panels considered in Parvadeh-I coal mine. Seven major effective parameters on FAR was selected …
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Design of coal mine roof support and yielding pillars for ...
@article{osti_5518512, title = {Design of coal mine roof support and yielding pillars for longwall mining in the Appalachian coalfield}, author = {Newman, D A}, abstractNote = {In this thesis, the existing Geomechanics Classification (Bieniawski, 1979) was modified for use in underground coal mines through the introduction of adjustment modifiers for strata weathering, horizontal stress, and ...
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University of Wollongong Research Online
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
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CDC - Mining - New Developments with the Coal Mine Roof ...
The Coal Mine Roof Rating (CMRR) has been incorporated into many aspects of mine planning, including longwall pillar design, roof support selection, feasibility studies, and extended cut evaluation. This paper presents recent improvements and application of the CMRR.
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NEW DEVELOPMENTS WITH THE COAL MINE ROOF RATING
The Coal Mine Roof Rating (CMRR) was developed nearly 10 years ago to try to fill this gap (1, 2). The CMRR weighs the geotechnical factors that contribute to roof competence, and combines them on single rating scale of zero to 100. The CMRR integrates years of research into geologic hazards in coal mining …
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IC 9313 Roof control of stress relief jointing near ...
ROOF CONTROL OF STRESS-RELIEF JOINTING NEAR OUTCROPS IN CENTRAL APPALACHIAN DRIFT COAL MINES By Gary P. sarnes! and Noel N. Moebs1 ABSTRACT This report discusses some practical applications of a geotechnical investigation conducted by the U.S. Bureau of Mines that can help mine operators meet revised Federal regulations in their roof control plans.
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Analysis of Mine Roof Support (AMRS) for US Coal Mines ...
During the late 1990s, NIOSH constructed a roof fall database from 37 coal mines located in all the major US coalfields. The database covered more than 1500 miles (2400 km) of drivage and included 900 roof falls [].Underground surveys yielded more than 100 "case histories," each one of which was a portion of a mine defined by its unique geology, depth, roof span, and roof support.
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Rock Load Estimation in Development Galleries and ...
Rock mass rating (RMR) plays important role in design and selection of support system (Ghosh, 2000). For stability assessment of rock mass it is very important to know the amount of rock load mobilized around the development gallery which is estimated using RMR (Singh et al., 2003, Barton et al., 1974, Bieniawski, 1984, and Ghosh et al., 1992). In Indian coal mines, Central Mining Research ...
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