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Cleveland Potash - triumph over adversity
150A
goaf edges and subsequent depillaring operations are described. Production and productivity, subsidence, and safety aspects are discussed. 883375
Ground free~ag of Asfordby Brown, P A Mis Engr V147, N315, Dec 1987, P277-281 Coal Measures at Asfordby colliery are overlain by 80m of water bearing strata. The freezing of this strata to permit shaft sinking is described. Careful monitoring during the drilling of 85 freeze holes was undertaken since inaccurate positioning would prolong freeze time. As a result, only 1 hole was redrilled. Brine was used to freeze the ground from a depth of 275m, where a freeze chamber was constructed.
883380
Interaction during ovennini~ for Iongwall operations Wu, W; Haycocks, C Proc Fourth Annual Workskop Generic Mi~ral Teclmology Center, M i ~ Systems D~sign ~ Gcomul Control, Moscow, Idaho, 20-21 October 1986 P45-56. Publ Blacksburg: Virginia Polytechnic Institute and State University, 1986 The large horizontal extent of longwall openings and the caving inherent in the system increase seam interaction problems in multi-seam coal mines as longwalling replaces room and pillar exploitation. Photoelastic models of a multiseam mine have been constructed. Maximum shear stress distribution near the longwall face, effect of relative location of the longwall face, direction of maximum shear stress near the face, effect of innerburden thickness and layering, and possible failure mechanisms were studied.
883376
Thin seam mining in the Holly Lane seam at Holditch
883381
Comery
Alternative methods for ~ ~ steeply ~ eeal Hall, C J; Willoughby, W Proc Fourtk Ammal Workskop Gamie Mimmi Y ~ Center, Mbte Systom Dosigm ~ Grmmd CoaWol, Moscow, ldako, 20-21 October 1986 P101-113. Publ Bl~ksburg: Virginia Polytechnic Institute and State University, 1986
• Hollins, R C
Mira Eagr VI47, N315, Dec 1987, P296-302 Extraction techniques for a thin seam comprising lm of coal and 0.18m of soft dirt, along a 260m face at over 1000m depth, are presented. The strata above and below the seam are hard mudstone, causing drilling problems for roof-bolts, and the area has been extensively overworked by numerous seams, with pillar edges crossing the working area. Machinery and support techniques are discussed. 883377 Anger enhmem Sava~m coal extraeti~ S A Mira Worm V6, N9, Oct 1987, 1'92-95 Auger mining is used where conventional underground or opencast mining is too costly or unsafe, eg steeply dipping seams. An auger miner is used at Savmore, South Africa, to mine coal under a highwall left by opencast mining, and extract reserves which would have been abandoned. 883378
ClevdMd Potash - triumph over adversity S A MiR World V6, NIO, Nov 1987, P30-35 Use of the stress relief system of mining to extract potash at Boulby, Yorkshire, is described. 5 or 6 parallel tunnels are constructed, separated by pillars in a chevron pattern. As mining advances, the pillars of the outer tunnels fracture and the roof collapses. This releases pressure in the central tunnel which remains intact. The technique has higher productivity than room and pillar used previously. gg3379
Effnets of soft ~mr iataactioa in ~ coal minkl Chugh, Y P; Chandrashekhar, K; Caudle, R D; Shankar, S; Nath, R Proc Fomrtk Amumi Workskop Gemri¢ Mism,al Texkmiogy Center, Mime Systems D e ~ ¢~d Grolmd Costlgol, Moscow, ldako, 20-21 October 1956 P33-43. Publ Biacksburg: Virginia Polytechnic Institute and State University, 1986 Design of mine workings under weak floor conditions requires knowledge of in-piace deformation characteristics of floor strata and their interaction with immediate roof strata and coal pillar. Geomechanical properties of floor strata from a mine in Illinois, USA, were measured in the laboratory and in borehole shear tests. Beating capacity was measured in situ under as mined and soaked conditions. Floor strata movemerits, convergence, pillar load c ~ s , and surface subsidence were monitored. Attempts are being made to relate mine bchaviour with floor properties.
The Eastside coal deposit, Colorado, USA, is a 20ft thick seam which dips at 54 deg. Mining methods used to exploit steeply dipping coal in other parts of the world are examined: sublevel caving, top slicing, shrinkage stoping, sublevel stoping, cut and fill, room and pillar, and vertical crater retreat. Equipment, layout, economics, and extraction potential are considered. The necessity of treating each case on its merits is emphasised. 883382
Mine systems~
~~comrot
Hoskins, J; Werner, M; McMahoni T; Lourence, P; Lacerda, L Proc Fmtrtk A~uml Workskop Gemric Mkm~l T ~
Center,Mime S.VStems~ ~ 6~omd Cmm.Rl,Moscow, Idaho, 20-21 Octaber lJ~6 PI83-19L ~ I Blaeksb~$: Virginia Polytechnic Institute and State University, 1986 Two projects are described. The first involves the testing of Foam Concrete Raise Prep (FCRP) in a test structm'e as an alternative to wooden raise p ~ t i o n s t r n c t ~ . ~ second considers the feasibility of a d o r n of uadexhand longwall stoping in a deep vein silver.lead mine. Finite ~ t : m o d e l , ling of a stope indicates closures and crown ~ r s ~ are acceptably low, and stress concentrations w ~ could lead :to rockburst are reduced. Field observations are in broad agreement with predictions. The planning and logistics of using this method in the mine are then ~ initially a ~ l ual simulation to illustrate the basic procedures, then: a computer model. 883383 Support of lell~ali woO..Iqs hi ddek seam extraegm Isaac, A K; Smith, P E n,: Groz~t M ~ ml ~ ~ to ~ ~
(papers to t k SJmi#ali~a, ~ , A~ 213. Pubi Parkville: AuslMM, 1986
1 ~ ) P204,
Correct selection of the underground equ~lgl~t, power loader, face conveyor, and powered supports, dete~nnines the effectiveness of strata control in longwali ~ ~ experiences suggest different behaviour from ~ t p ~ u s l y encountered with thin seams. Structural integrity o f the face wall is influenced by seam discontinuities, natural joints, mining induced fractures, and the presence of stone bands or dirt
© 1988 Pergamon Press pie. Reproduction not permitted
goaf edges and subsequent depillaring operations are described. Production and productivity, subsidence, and safety aspects are discussed. 883375
Ground free~ag of Asfordby Brown, P A Mis Engr V147, N315, Dec 1987, P277-281 Coal Measures at Asfordby colliery are overlain by 80m of water bearing strata. The freezing of this strata to permit shaft sinking is described. Careful monitoring during the drilling of 85 freeze holes was undertaken since inaccurate positioning would prolong freeze time. As a result, only 1 hole was redrilled. Brine was used to freeze the ground from a depth of 275m, where a freeze chamber was constructed.
883380
Interaction during ovennini~ for Iongwall operations Wu, W; Haycocks, C Proc Fourth Annual Workskop Generic Mi~ral Teclmology Center, M i ~ Systems D~sign ~ Gcomul Control, Moscow, Idaho, 20-21 October 1986 P45-56. Publ Blacksburg: Virginia Polytechnic Institute and State University, 1986 The large horizontal extent of longwall openings and the caving inherent in the system increase seam interaction problems in multi-seam coal mines as longwalling replaces room and pillar exploitation. Photoelastic models of a multiseam mine have been constructed. Maximum shear stress distribution near the longwall face, effect of relative location of the longwall face, direction of maximum shear stress near the face, effect of innerburden thickness and layering, and possible failure mechanisms were studied.
883376
Thin seam mining in the Holly Lane seam at Holditch
883381
Comery
Alternative methods for ~ ~ steeply ~ eeal Hall, C J; Willoughby, W Proc Fourtk Ammal Workskop Gamie Mimmi Y ~ Center, Mbte Systom Dosigm ~ Grmmd CoaWol, Moscow, ldako, 20-21 October 1986 P101-113. Publ Bl~ksburg: Virginia Polytechnic Institute and State University, 1986
• Hollins, R C
Mira Eagr VI47, N315, Dec 1987, P296-302 Extraction techniques for a thin seam comprising lm of coal and 0.18m of soft dirt, along a 260m face at over 1000m depth, are presented. The strata above and below the seam are hard mudstone, causing drilling problems for roof-bolts, and the area has been extensively overworked by numerous seams, with pillar edges crossing the working area. Machinery and support techniques are discussed. 883377 Anger enhmem Sava~m coal extraeti~ S A Mira Worm V6, N9, Oct 1987, 1'92-95 Auger mining is used where conventional underground or opencast mining is too costly or unsafe, eg steeply dipping seams. An auger miner is used at Savmore, South Africa, to mine coal under a highwall left by opencast mining, and extract reserves which would have been abandoned. 883378
ClevdMd Potash - triumph over adversity S A MiR World V6, NIO, Nov 1987, P30-35 Use of the stress relief system of mining to extract potash at Boulby, Yorkshire, is described. 5 or 6 parallel tunnels are constructed, separated by pillars in a chevron pattern. As mining advances, the pillars of the outer tunnels fracture and the roof collapses. This releases pressure in the central tunnel which remains intact. The technique has higher productivity than room and pillar used previously. gg3379
Effnets of soft ~mr iataactioa in ~ coal minkl Chugh, Y P; Chandrashekhar, K; Caudle, R D; Shankar, S; Nath, R Proc Fomrtk Amumi Workskop Gemri¢ Mism,al Texkmiogy Center, Mime Systems D e ~ ¢~d Grolmd Costlgol, Moscow, ldako, 20-21 October 1956 P33-43. Publ Biacksburg: Virginia Polytechnic Institute and State University, 1986 Design of mine workings under weak floor conditions requires knowledge of in-piace deformation characteristics of floor strata and their interaction with immediate roof strata and coal pillar. Geomechanical properties of floor strata from a mine in Illinois, USA, were measured in the laboratory and in borehole shear tests. Beating capacity was measured in situ under as mined and soaked conditions. Floor strata movemerits, convergence, pillar load c ~ s , and surface subsidence were monitored. Attempts are being made to relate mine bchaviour with floor properties.
The Eastside coal deposit, Colorado, USA, is a 20ft thick seam which dips at 54 deg. Mining methods used to exploit steeply dipping coal in other parts of the world are examined: sublevel caving, top slicing, shrinkage stoping, sublevel stoping, cut and fill, room and pillar, and vertical crater retreat. Equipment, layout, economics, and extraction potential are considered. The necessity of treating each case on its merits is emphasised. 883382
Mine systems~
~~comrot
Hoskins, J; Werner, M; McMahoni T; Lourence, P; Lacerda, L Proc Fmtrtk A~uml Workskop Gemric Mkm~l T ~
Center,Mime S.VStems~ ~ 6~omd Cmm.Rl,Moscow, Idaho, 20-21 Octaber lJ~6 PI83-19L ~ I Blaeksb~$: Virginia Polytechnic Institute and State University, 1986 Two projects are described. The first involves the testing of Foam Concrete Raise Prep (FCRP) in a test structm'e as an alternative to wooden raise p ~ t i o n s t r n c t ~ . ~ second considers the feasibility of a d o r n of uadexhand longwall stoping in a deep vein silver.lead mine. Finite ~ t : m o d e l , ling of a stope indicates closures and crown ~ r s ~ are acceptably low, and stress concentrations w ~ could lead :to rockburst are reduced. Field observations are in broad agreement with predictions. The planning and logistics of using this method in the mine are then ~ initially a ~ l ual simulation to illustrate the basic procedures, then: a computer model. 883383 Support of lell~ali woO..Iqs hi ddek seam extraegm Isaac, A K; Smith, P E n,: Groz~t M ~ ml ~ ~ to ~ ~
(papers to t k SJmi#ali~a, ~ , A~ 213. Pubi Parkville: AuslMM, 1986
1 ~ ) P204,
Correct selection of the underground equ~lgl~t, power loader, face conveyor, and powered supports, dete~nnines the effectiveness of strata control in longwali ~ ~ experiences suggest different behaviour from ~ t p ~ u s l y encountered with thin seams. Structural integrity o f the face wall is influenced by seam discontinuities, natural joints, mining induced fractures, and the presence of stone bands or dirt
© 1988 Pergamon Press pie. Reproduction not permitted