Estimation of non-effective width for different panel shapes in room and pillar extraction

Loui, John P.; Sheorey, P.R.

doi:10.1016/s1365-1609(01)00074-0

Cited by 15 publications

(6 citation statements)

References 1 publication

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“…To ensure the long-term stability of a coal pillar, if the coal seam is weak, the ratio should be larger than 0.65 [ 67 , 68 ]. If the safety factor is larger than 1.6, it can ensure the long-term stability of the coal pillars [ 69 , 70 ]. The calculation methods of the ratio and the safety factor are shown in Eq ( 10 ) and Eq ( 11 ) respectively [ 71 , 72 ].…”

Section: Coal Seam #2 Mining After the Double Strip Mining In The Undmentioning

confidence: 99%

The pressure relief protection effect of different strip widths, dip angles and pillar widths of an underside protective seam

et al. 2021

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To design underside protective seam strip layout. Similarity model experiments, numerical simulations and theoretical calculations are used to quantitatively study the pressure relief protection effect of different strip widths, dip angles and coal pillar widths of a thin underside protective seam under deeply buried conditions. The optimal strip width range is obtained according to the change law of strain during the mining process of the underside protective seam in a similar model experiment. The change law of the expansion of the protected coal seam is obtained and the fitting surfaces among the dip angle and strip width of the coal seam with the protection distance and pressure relief angle along the strike and dip of the protected coal seam are established according to the numerical simulation results of underside protective seam mining. It is concluded that the best pressure relief effect can be achieved when the dip angle is 16.7° and the strip width is 70 m. According to the stability threshold of coal pillars considered in strip mining theory, the coal pillar width is calculated to be 50 m. Similarity model experiments and numerical simulations of protected coal seam mining verify the pressure relief effect of the designed protective seam strip width and pillar width. A calculation method of the protective seam strip width, position and pillar width required by the specific width of the protected seam is proposed.

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Section: Coal Seam #2 Mining After the Double Strip Mining In The Undmentioning

confidence: 99%

The pressure relief protection effect of different strip widths, dip angles and pillar widths of an underside protective seam

et al. 2021

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“…Stability factor contours are extensively used to assess the failure or stability of underground excavations and many other stress analysis scenarios Loui et al (2007), Loui and Sheorey (2002) and Sheorey (1997). Though this method is the simplest form of numerical modeling analysis, it is still considered to be reliable and faster method for arriving at a solution.…”

Section: Elastic Simulation Using Stability Factor Contouringmentioning

confidence: 99%

Numerical Studies on Chip Formation in Drag-Pick Cutting of Rocks

Loui

Karanam

2011

Geotech Geol Eng

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A two dimensional non-linear finite element simulation model has been developed using a mathematical model for progressive rock failure for understanding the mode and sequence of rock failure under a drag pick cutter. Rock cutting simulation has also been done using linear elastic modeling using local stability factor contouring. It has been observed from the simulation results that during negative rake angle cutting the chipping occurs by shear failure of the elements. Whereas, in positive rake angle cutting, some elements were observed to fail in shear and some under tension. The predicted peak cutting force using the developed models was found to be up to 25% higher than the experimental values. The effect of input parameters such as rake angle, flank wear, depth of cut and rock properties on the predicted peak cutting force has been studied, verified from earlier experimental studies and compared with some earlier proposed theories on rock cutting. The elastic stress analysis model based on the stability factor contouring method has also been found to be an effective tool to bracket the expected peak cutting force for a given operational and rock parameters but failed to simulate the effect of pick geometry (rake angle) correctly. The non-linear simulation model using progressive rock element failure is superior to elastic linear stress analysis model by simulating the correct trends for all the rock and machining parameters.

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“…This is the most dangerous area of a room and pillar mine. Small increases in the intersection span can have extremely damaging effects on mine stability, particularly in areas where the roof is weak (Loui and Sheorey 2002). In order to maintain stable intersections the following key points should be addressed:…”

Section: Local Stability Issuesmentioning

confidence: 99%

Geological and geotechnical aspects of underground coal mining methods within Australia

et al. 2009

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About one quarter of the coal produced in Australia is by underground mining methods. The most commonly used underground coal mining methods in Australia are longwall, and room and pillar. This paper provides a detailed review of the two methods, including their advantages and disadvantages, the major geotechnical and operational issues, and the factors that need to be considered regarding their choice, including the varying geological and geotechnical conditions suited to a particular method. Factors and issues such as capital cost, productivity, recovery, versatility and mine safety associated with the two methods are discussed and compared. The major advantages of the longwall mining method include its suitability for mining at greater depth, higher recovery, and higher production rate compared to room and pillar. The main disadvantages of the room and pillar method are the higher risks of roof and pillar collapse, higher capital costs incurred as well as lower recovery rate.

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Estimation of non-effective width for different panel shapes in room and pillar extraction

Cited by 15 publications

References 1 publication

The pressure relief protection effect of different strip widths, dip angles and pillar widths of an underside protective seam

The pressure relief protection effect of different strip widths, dip angles and pillar widths of an underside protective seam

Numerical Studies on Chip Formation in Drag-Pick Cutting of Rocks

Geological and geotechnical aspects of underground coal mining methods within Australia

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