Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 21 for “"room and pillar"”.
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Numerical Modeling of Room-and-Pillar Coal Mine Ground Response
… challenge in rock mass engineering. Fall of roof and rib continue to present a hazard to underground personnel. Stability of underground openings is a prerequisite for successful underground coal mine workings. An adaptation of a civil engineering design standard for analyzing the stability of …
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Bump control design protocol for room-and-pillar retreat mining
… are the explosive failure of highly stressed pillars. The protocol was developed for room-and-pillar retreat mining conducted with available continuous miner technology. The inability of existing coal pillar equations to accurately represent the wide total extraction pillars required, forced …
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Microseismic Monitoring of a Room and Pillar Retreat Coal Mine in Southwest Virginia
… United States experienced over 3,300 injuries and 42 deaths between 2006 and 2012 from the fall of a roof or rib (MSHA, 2015). Out of the underground coal mining methods, room and pillar retreat mining lacks significant research to adequately understand the rockmass behavior associated with the …
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Subsidence Damaged Homes Over Room and Pillar Mines in Illinois (Ground Movements, Damage Criteria)
… is established between residential damage and ground movements over Illinois room and pillar mines. Using this ground movement-damage criterion and knowing the expected level of ground displacement house damage can be estimated. Subsidence characteristics observed at the ground surface over …
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Ground control ramifications and economic impact of retreat mining on room and pillar coal mines
… companies have to develop deeper deposits and increase percentage extraction to maintain production levels. Total extraction for room and pillar mines can only be achieved by pillar extraction. The unsupported roof increases during pillar extraction and hence the cost of ground control also …
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The prediction of surface subsidence due to room and pillar mining in the Appalachian coalfield
… with longwall mining. Investigations into room-and-pillar subsidence have often been neglected, despite the fact that this is the predominant mining system in this country. However, the recent economic incentives which have caused the need for higher secondary extractions in room-and-pillar …
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Pillar load transfer mechanisms in multi-seam mining
The mechanisms controlling pillar load transfer from an overlying seam to subadjacent workings is investigated. Mine geometry and geology are researched as major variables affecting interaction between contiguously placed seams. The thesis includes photoelastic experimentation, finite element …
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The Prediction and Occurrence of Chimney Subsidence in Southwestern Pennsylvania
… of the commonwealth. However, the mines abandoned before today's strict environmental regulations have degraded over half of Pennsylvania's counties. Subsidence incidents, known as chimney caves, are in the form of sinkholes and develop above abandoned room-and-pillar mines. Chimney caving …
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A Dynamic Programming Approach to Identifying Optimal Mining Sequences for Continuous Miner Coal Production Systems
… are the source of 33% of US coal production and 60% of worldwide coal production. Room-and-pillar mining with continuous miners has been the most common production system used in these mines since the 1960s. The introduction of continuous miners mechanized the underground coal mining industry …
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A New Style of Simulation Model for Mining Systems
… modeling to predict productivity of underground room-and-pillar mining systems are well-known and documented. These algorithms consider the time-varying relationships between mining equipment for a given geometry of operations as well as other constraints. This study presents a newly developed, …
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Mechanics of interseam failure in multiple horizon mining
… three approaches: case studies, physical models and computer analysis. Specific examples of multi-seam mines with the underlying seam mined first prior to the mining of the overlying seam were studied with some design guidelines drawn from them. A loading frame capable of testing model blocks of …
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Gateroad Design in Overlying Multi-Seam Mines
… first is to determine the location, magnitude and duration of stress transferred from lower seam mines; and the second is to predict the effect of stress transferred from lower seam mines on opening stability. To solve these problems for both longwall and room-and-pillar mines, case study data …
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Novel Uses of Distributed Optical Fiber Sensing for Geo-Mechanical Monitoring
… is crucial for ensuring workplace safety and efficiency. As mines become deeper and more complex, the need to monitor larger volumes of rock during mining becomes impractical with existing instruments due to high costs. Distributed Optical Fiber Sensing (DOFS) is a powerful technology with …
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Optimizing Pillar Design for Improved Stability and Enhanced Production in Underground Stone Mines
… mass behavior for maximizing safety. Optimizing pillar design is essential for preventing hazardous incidents and improving production in room-and-pillar mines. Maintaining regional and global stability is complicated for underground carbonate or stone deposits, where extensive fracture networks …
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An investigation into the modeling of ground deformations induced by underground mining
… were analyzed in an effort to better understand immediate roof behavior and surface displacements. Strata deformation characteristics above longwall and room-and-pillar mines in the eastern U.S. coalfields were evaluated and a numerical procedure was developed for calculating surface …
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Pillar design for St. Peter sandstone formation
<p>"Silica sands produced primarily from St. Peter Sandstone are used for hydraulic fracturing in the petroleum industry, glassmaking, chemicals, ceramics, filtration and the foundry industry in the US. The recent high demand for silica sands for hydraulic fracturing has triggered increased …
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A Method for Evaluating the Application of Variable Frequency Drives with Coal Mine Ventilation Fans
… are adjusted to change the amount of airflow and pressure to meet ventilation requirements. Typically, the fan does not operate at its optimum efficiency, which only occurs in a narrow band of air pressures and quantities. The use of variable frequency drives (VFDs), which control fan speed, …
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Investigation of coal bumps in the Pocahontas No. 3 seam, Buchanan County, Virginia
… recover reserves of coal situated within barrier pillars in the Beatrice Mine using the room and pillar method have thus far been largely frustrated due to magnitude, in or near the working places shortly after commencement of retreat mining in a given area. Since pillar mining offers the …
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Integrating Laser Scanning with Discrete Element Modeling for Improving Safety in Underground Stone Mines
According to the Mine Health and Safety Administration (MSHA), between 2006 and 2016, the underground stone mining industry had the highest fatality rate in 4 out of 10 years, compared to any other type of mining in the United States. Additionally, the National Institute for Occupational Safety and …
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