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SME-ICGCM (1801)
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TITLE Subsidence and Uplift Prediction in German and Polish Hard Coal Mining
SUMMARY For the last 150 years, subsidence damage to the surface has been an unavoidable phenomenon associated with underground coal mining. In particular, the mechanization of mining methods in multiple seam mining and the concentration of mining activities in densely populated European metropolitan areas (e.g., Ruhr, Upper Silesian industrial region) have led to mining having a very strong influence on the earth?s surface. In both these regions, surface subsidence of more than 20m has been reported up...
AUTHOR Preusse, Axel
TITLE The Extraction of Main Heading Pillars with a Longwall at Nre Wongawilli Colliery
SUMMARY To maintain longwall continuity, NRE Wongawilli Colliery extracted the approximately 20-year-old Thompson Mains and in doing so, 20 roadways were holed into during longwall retreat. The orientation of these roadways with regard to the longwall face varied between (i) a parallel alignment where the entire roadway was simultaneously subjected to a significant increase in vertical stress on holing and (ii) a more favorable high angle of alignment, meaning that only a portion of the roadway was subj...
AUTHOR Stone, Ry
TITLE The Evaluation of Empirical Coal Pillar Strength Formula Based on Uncertainty Criterion
SUMMARY Several empirical equations to estimate coal pillar strength have been presented in academic studies. The development processes of these equations are similar and are usually obtained by fitting the mathematical function (curve) to field data. One of the best criteria to evaluate the quality of fitting for such equations is the correlation coefficient R2, which has limited applicability. It is necessary to calculate the correlation coefficient access to the initial data for which the equation is...
AUTHOR Hosseini, Navid
TITLE Massive Pillar Collapse: a Room?and?Pillar Marble Mine Case Study
SUMMARY The Mine Safety and Health Administration?s Roof Control Division responded to a massive ground failure at an underground marble mine in northern Georgia. The ground failure occurred in a benched area that had been abandoned in the early 1990s. It involved the failure of an estimated 19 pillars, in conjunction with a massive roof fall of an undetermined extent that was at least 60 ft high. Pillars in the benched area had been mined nominally 40 x 40 feet to a height of 50 feet ft, with 40-ft min...
AUTHOR Phillipson, Sandin E.
TITLE A Stability Factor for Supported Mine Entries Based on Numerical Model Analysis
SUMMARY This paper addresses the need for a method to compare the effectiveness of different support systems when designing ground support in coal mines. At present, support design methods include empirical methods based on observations of past performance of installed support systems, analytical methods where the roof is typically simulated by elastic beams and numerical model analysis. The approach presented in this paper estimates the relative stability of a support design through geotechnical evalua...
AUTHOR Esterhuizen, Gabriel S.
TITLE Prediction of First Weighting Distance in Longwall Coal Mining By 3D Numerical Modeling ? A Case Study
SUMMARY In longwall coal mines, estimation of roof strata condition, sequence of loading, and supporting requirements are of a high degree of importance, and they are directly related to production and safety. Also, a prediction of the initial caving distance is rather complicated to calculate, because there are many parameters that effect caving process?roof and floor strata conditions, thickness of immediate roof, depth of cover, excavation geometry, and magnitude, and direction of principal stresses....
AUTHOR Manteqi, Haile
TITLE Post?Collapse Seismicity of the Crandall Canyon Mine Using Double Difference Relocations
SUMMARY In 2007, the University of Utah Seismograph Stations (UUSS) temporarily expanded its seismic monitoring network in Emery County, Utah, in response to the August 6 Crandall Canyon mine collapse that trapped six workers. In spite of this additional coverage, no seismic events were located in the area during a six-day period (gap) from August 8 to August 13.The Mine Safety and Health Administration (MSHA) ?Command Center Log Books? however, contain references to 16 instances of underground ?bumping...
AUTHOR Kubacki, Tex M.
TITLE A Mine Evaluation Protocol Using Applied Rock Mechanics Techniques
SUMMARY The author has developed a seven-step process called the Applied Rock Mechanics (ARM) Protocol that the author has used to solve numerous roof stability problems in mines throughout North America since 1975. It is a practical evaluation process using trained observation, innovative data collection instrumentation, video borehole cameras, analytical processes, and controlled testing methods that have become highly effective in solving ground control problems in every type of underground mine. Thi...
AUTHOR Petersen, Gary B.
TITLE A Management System to Develop Occupational Health & Safety in Ground Control Operations of Underground Mines
SUMMARY Falls of ground have historically been the main cause for fatalities in underground mines. Although recent advances in technology have reduced the number of such accidents, when failures occur they usually result in severe consequences. Risks of rock falls, use of heavy machinery and electrical apparatus, entry to confined spaces, working in noisy and dusty environments, and working on unstable platforms are some of the hazards in ground control operations. Managing these risks requires a manage...
AUTHOR Oraee, Kazem
TITLE The Estimation of Ground Control Risk By Real?Time Quantitative Visual Assessments
SUMMARY Roof and rib falls are the basic ground control hazards associated with underground roadways during development, stand up and, if applicable, retreat. Falls of ground can happen following the deterioration of supports or rock conditions over time, and particularly as a consequence of continuing rock deformation and/ or failure to install adequate support. Once developed, the risk of a failure is increased due to the effects of time as well as to front abutment stresses through retreat mining. Th...
AUTHOR Garcia, Alexander