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Rock engineering problems are often data-limited. In mining, case histories are a rich potential source of data. Each pillar that is developed, or stope that is mined, is a full-scale test under real conditions. Many other fields that deal with highly complex, poorly-understood systems rely .
Practical coal pillar design considerations that incorporated the results of FEM and field measurements were presented by Su and Hasenfus [1996]. Nonlinear pillar strength curves were first presented to relate pillar strength to w/h ratio under simulated strong mine roof and floor conditions (figure 1).
155 COAL PILLAR STRENGTH AND PRACTICAL COAL PILLAR DESIGN CONSIDERATIONS By Daniel W. H. Su, Ph.D.,1 and Gregory J. Hasenfus2 ABSTRACT This paper demonstrates that finite-element modeling can be used to predict in situ coal pillar strength,
MNGN 316- Coal Mine Design (2001-2002) MNGN 598- Equipment Economics, Maintenance, and Automation (planned 2015) ... "Yield Pillar Design at Depth Based on Review of Case Histories." Transactions Volume 316, 2004, Society for Mining, Metallurgy and Exploration, Inc., Littleton, CO, p.
[PDF]Pillars have been used since the earliest days of mining. The first scientific pillar design method for US coal mines was developed more than a century ago. Yet, as late as the 1980s, no design technique had achieved wide acceptance, and few pillars were truly engineered . Most mines sized their pillars using local rules of thumb that were based on past experience.
@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 ...
[PDF]Thus, the design of any underground opening must consider roof/pillar and floor as one structural system. This paper presents guidelines for the design of mine floors, including the necessary field and laboratory investigations and the determination of the bearing capacity of floor strata.
[PDF]A reasonable mining pillar for highwall mining is conducive to safe and efficient mining. The highwall mining pillar design is a direct function of the coal strength, opening height, opening width, .
[PDF]minimize barrier failures and mine drainage problems. This research deals with the design of outcrop barrier widths, potential problems associated with impounding large volumes of water in an abandoned bi tuminous coal mine, outcrop grouting, and measures necessary to prevent seepage through a coal barrier. The Bureau of Mines authorized Dames ...
The far reaching consequences of designing pillars for coal mines, while retaining concern for safety and economics, are cause for the search for refinement of the existing engineering methods to continue. Coal pillars, while having various functions within the overall mine plan, are the basic structural elements that assure the stability of a mine.
[PDF]Abutment - In coal mining, (1) the weight of the rocks above a narrow roadway is transferred to the solid coal along the sides, which act as abutments of the arch of strata spanning the roadway; and (2) the weight of the rocks over a longwall face is transferred to the front abutment, that is, the solid coal ahead of the face and the back abutment, ...
[PDF]By 1980, the U.S. mining community had reached a broad consensus regarding coal pillar design. The pillar load could be estimated from the tributary area theory, and the pillar strength from empirical formulas and laboratory coal strength testing. Then the growth of longwall mining required new thinking. Recently, powerful design methods have emerged from analysis of large data bases of real-world pillar .
[PDF]DEVELOPMENTS IN COAL PILLAR DESIGN AT SMOKY RIVER COAL LIMITED, ALBERTA, CANADA by Dr. Peter Cain, P.Eng. Senior Ground Control Engineer Smoky River Coal Limited Grande Cache, AB. T0E 0Y0 CANADA ABSTRACT Smoky River Coal Limited (SRCL) mines low volatile metallurgical coal by surface and underground methods in the foothills of the Rocky Mountains of Alberta.
different approach to pillar design. He treated pillar design as a problem in mechanics, rather than one of curve-fitting to experimental or case history data. A pillar was analyzed as a complex structure with a nonuniform stress gradient, a buildup of confinement around a .
[PDF]rock bursts in underground coal mines. Each mine operator is required by 30 CFR 75.220 (a) (1) to develop and follow a roof control plan, approved by the Mine Safety and Health Administration (MSHA) District Manager, that is suitable to the prevailing geological conditions, and the mining system to be used at the mine.
This chapter focuses on the design, examination, maintenance, and evaluation of bleeder systems in underground coal mines. The history of coal mine explosions in the United States is a reminder of the importance of ade-quate ventilation. Some of those disasters were .
[PDF]Coal pillar design has been based on generalised formulae of the strength of the coal in a pillar and experience in localised situations. Stress measurements above and in coal pillars indicate that the actual strength and deformation of pillars varies much more than predicted by formulae.
Rock load = 4.80 t/m2 Hence, rock load in galleries and splits = 4.80 t/m. 2. To support the rock load we need to give support higher than the rock load at that area so that the roof will not fall. Type and capacity of various supports are chosen from Table 4 for design of Support system in bord and pillar workings.
The far reaching consequences of designing pillars for coal mines, while retaining concern for safety and economics, are cause for the search for refinement of the existing engineering methods to continue. Coal pillars, while having various functions within the overall mine plan, are the basic structural elements that assure the stability of a mine.
The paper points out that bord-and-pillar mining is the most important method of coal extraction in South African underground coal mines, and advocates that pillar design procedures should be ...
Coal produced from underground mines in South Africa is mainly extracted by the bord- and-pillar method in which the overburden is supported by coal pillars. The stability of these pillars is a major safety concern, since failure of the pillars could result in the collapse of several square kilometres of a mine.
MNGN 316- Coal Mine Design (2001-2002) MNGN 598- Equipment Economics, Maintenance, and Automation (planned 2015) ... "Yield Pillar Design at Depth Based on Review of Case Histories." Transactions Volume 316, 2004, Society for Mining, Metallurgy and Exploration, Inc., Littleton, CO, p.
Other underground coal mines are laid out in a checkerboard of rooms and pillars (Fig. 2), and the mining operation involves cyclical, step by- step mining sequences. The rooms are the empty areas from which coal has been mined, and the pillars are blocks of coal (generally 40 to 80 feet on a .
[PDF]3. Pillar Design Methods Pillar design in coal underground mines should be carried out so as to achieve two goals. These include the provision of a high level of safety and coal recovery. Before development of personal computers, mining designers designed coal pillar by .
Jan 16, 2018 · The pillar design guidelines have been incorporated into software packages that can be used for the preliminary design of pillars for longwall gateroads and retreat mining in coal and in limestone mines. The software packages are: ALPS (Analysis of Longwall Pillar Stability) for longwall gateroad pillars in coal
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In coal mines, pillar failures are known as squeezes because the roof squeezes down, crushing the pillars. Once one pillar fails, the weight on the adjacent pillars increases, and the result is a chain reaction of pillar .
prevalent in the Indian underground mines is the Bord and Pillar method of mining because of its history and ease of operation. The most important aspect of Bord and Pillar mining is the design of pillars.
Coal mine pillar design has been the subject of sustained and intensive research in the major coal producing countries of the world. Pillar design and stability are two of the most complicated and extensive problems in mining related to rock mechanics and ground control subjects.
Although some 90% of underground coal mining in the United States is by the room-and-pillar method, no comprehensive design procedure is available for this purpose. Following a survey of over 200 coal mines, typical mining conditions and room-and-pillar configurations were analyzed during a .
[PDF]Mines Research and Advisory Committee) project COL337 'Coal Pillar Design Procedures', and it focuses on situations where scaling represents the primary threat to the pillars. In this process coal strength remains unaltered and the weakening of the pillars is due entirely to a .
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