- Email: [email protected]
Criteria for selecting a boom-type roadheader
78A
892218 Prediction of peak particle velocity and peak air pressure generated by buried explosion Gupta, R N; Pal Roy, P; Singh, B lnt J Min Geoi Engng V6. NI, March 1988, P15-26 Three sets of formulae, expressed as functions of dynamic elastic constants of rock, obtained from density, longitudinal and shear wave velocities, and some design parameters involved in a buried explosion, are explicitly derived to predict peak particle velocity (PPV) and peak air pressure (PAP). Separate equations are derived to estimate PPV and PAP for inside, outside and at the boundary of the crater zone. The formulae were applied to 7 rock types, including diorite, granite and limestone, and then verified using data from in situ controlled blasting.
892219 Scientific approach to blast design. The influence of rock characteristics Rorke, A J Quarry Manage Oct 1988. P33-42 Successful blast design produces a diggable rock pile with minimum adverse environmental impact. The outcome of the blast depends upon the nature and characteristics of the rock, the real performance of the explosive within the rock, and blast design. Rock characterisation in terms of dynamic and static properties, effects of dynamic properties on fragmentation and heave, influence of rock structure, and effects of explosives performance on blast qualities have been analysed using computer simulations.
892220 Model study of crater blasting Fourney, W L; Dick, R D; Simha, K R Y Rock Mech Rock Engng V21, N3, July-Sept 1988, P183-205 Cratering experiments to date have been unable to quantify the effects of stemming on cratering and fragmentation. To clarify this, small scale model tests using granite, Hydrostone (gypsum based), and plexiglass blocks were carried out. Results indicate that fracture and fragmentation in single hole crater blasting situations are not influenced by stemming. Radial cracks are formed before the crater formation process begins, and the crater initiates at the borehole wall and propagates to the surface. Crater formation is heavily dependent on stress wave effects and only in a minor way on borehole pressurisation. Scale effects and limitations on extrapolation of small scale model tests are discussed.
892221 Getting the right 'bang' in the right place at the right time Martin, D Tunn Tunnlg V20. N9, Sept 1988, P32-37 The non-electric detonator represented a significant development in blasting technology. It has no blast effect since it is confined in a tube, is not sensitive to electric currents and is safer than traditional detonators. Another improvement in blasting was development of emulite, a water-in-oil emulsion, which is safer than nitroglycerine, has good rock breaking qualities, and is stable and water resistant. The smooth blasting technique is outlined and charging equipment described.
892222 Some suitable patterns of drilling and controlled blasting in the surrounding of four hydroelectric projects in India Gupta, R N: Pal Roy, P: Bagchi, A; Singh, R B: Singh, B Proc Symposium on Rock Mechanics and Power Plants, Madrid, 12-16 Sept 1988 VI. P49-56. Publ Rotterdam: A A Balkema, 1988 Prevention of blasting damage to existing structures or part completed projects is essential. Although geological parameters are set, borehole, burden, spacing, stemming, explosive type, and delay firing may be varied to minimise vibration, often at little or no extra cost. A critical analysis of blast design is presented, and application of its results to four major projects described.
892223 Longer rounds to improve tunnelling and development work Niklasson, B; Holmberg, R; Olsson, K; Schorling, S Proc Tunnelling '88, London, 18-21 April 1988 P213-221. Publ London: IMM, 1988 Work in a Swedish iron ore mine where change to large scale sublevel caving is being investigated is presented. Development of the drilling, blasting, scaling, loading, and transport processes in drift driving is described. Currently available drill rigs are found to be inefficient in pulling drill rounds 7m long. Effects on setting times for other operations in the cycle, blast design, and performance are considered.
Crushing and grinding 892224 Fundamental study of dry and wet grinding from the viewpoint of breaking strength Kanda, Y; Abe, Y; Yamaguchi, M; Endo, C Powder Technol V56, NI. Sept 1988, P57-62 Differences between wet and dry grinding have been studied. Bending tests were conducted on a glass material to investigate the quantitative effects of water on bending strength, crack propagation and the relationship between strength and number of cracks. Results show crack length is greater in water than in air, bending strength is lower in water than in air, and a wet grinding process is useful from point of view of strength of solids.
Machine excavation 892225 Roadheader cutting heads and picks Hurt, K G Colliery Guard V236, N9, Sept 1988, P332-335 As roadheaders have become larger and more sophisticated, cutterhead design has assumed increasing importance. Design trends are illustrated, with the change from radial to point or forward attack picks, improvements in pick layout to minimise vibration, and water jet assistance being considered. Limits to roadheader cutting ability are also discussed.
892226 Criteria for selecting a boom-type roadheader Schneider, H Min Mag Sept 1988, P183-187 The simplest classification of boom type roadheaders is by weight. This allows the engineer to obtain information on approximate price on a weight basis, size, and field of applications. The areas where roadheaders in the 5 weight classes
~! 1989 Pergamon Press plc. Reproduction not permitted
79A suggested have been applied are described. Three types of cutter head, in line, transverse, and cylindrical, advancing and articulated booms, and water jet assisted cutting, and their particular advantages are considered. Finally, special project requirements are examined.
Rock and Soil Reinforcement and Support
892231 Ten thousand anchorages in rock Barley, A D Ground Engng V21, N7, Oct 1988, P24-35 Use of ground anchors in chalk, mudstones, siltstones, shales and marls, and sandstones is considered using data from a variety of projects. For each rock type, development of construction method, ultimate bond, failure mechanism and working anchorages are considered, and a data table presented showing SPT values, fixed length, diameter, working bond, test bond, ultimate bond and F value for a number of sites. 892232 Stability of rock masses reinforced by passive, fully-grouted rock bolts Sharma, K G; Pande, G N Int J Rock Mech Min Sci V25, NS, Oct 1988, P273-285
See also: 892407 892227 Rock support Hoek, E; Wood, D F Min Mug Oct 1988. P282-287 A comprehensive evaluation of support requirements for underground hard rock mining is presented. Suggested rock support for conditions from good quality rock under low in situ stress to poor quality rock in shear zones is illustrated in tabular form. Active rock reinforcement, the range of bolts, dowels, bars and anchors, and passive support, mesh, straps, shotcrete and steel sets, are illustrated, and areas for their application discussed.
Bolts and anchors 892228 Australian mining - the role of roofbolting Banford, C R Colliery Guard V236, N9, Sept 1988, P315-318 As open pit mine reserves have become depleted, deep longwall mining has assumed increasing importance in Australia. The historical development of roofbolting in Australian pits and currently used methods and equipment are described. Factors which must be taken into account to adapt these practices to British conditions are examined. The role of the strata control group at ACIRL is also described. 892229 Roofbolting for retreat Eaton, J Colliery Guard V236, N9, Sept 1988, P320-322 Key areas where cost reductions are possible in British coal mines are outlined. The mechanism of roadway stability and influences of rock mass strength, stress level and orientation, and size and shape of roadway are considered. The use of active roofbolt support for longwall mining with retreat as a specific economy measure is described. 892230 Ten thousand anchorages in rock Barley, A D Ground Engng V21, N6, Sept 1988. P20-29 An overview of the use, effectiveness and development of rock anchorages, based on data from 10,000 cases, is presented. Fixed anchor dimensions, drilling and flushing methods, borehole alignment, methods to ensure grout tightness of a fixed anchor length, grout and grout mixing, and anchor tendons are considered.
The behaviour of a jointed rock mass with fully grouted passive reinforcements is simulated using the equivalent material approach, which distributes the influence of rock joints as well as rock bolts throughout the rock mass. Properties of the rock material, joint sets and reinforcement sets are discussed, and a finite element program developed to analyse the problem of a jointed rock slope and compute factors of safety against collapse. It is shown that the dilatancy of rock joints and the orientation of rock bolts are the most important factors in determining the effectiveness of passive, fully grouted rock bolts. 892233 Estimation of gain in pillar strength due to bolting: technical note Sheorey, P R lnt J Rock Mecli Min Sci V25, NS, Oct 1988. P321-326 Wilson's theory to define pillar strength in terms of the vertical stress developed in the failed rock zone has been extended to obtain the probable strength of bolted pillars which are intact before bolting. The approach assumes that bolting becomes fully effective only when the pillar is about to fail. Estimation of the triaxial parameter and strength is outlined. 892234 Response of grouted roof bolts to blast loading: technical note Otuonye, F O lnt J Rock Mech Min Sci V25, NS. Oct 1988. P345-349 The transfer of stresses from rock to rock bolt and the bolt's response during blast loading have been studied, using a time series and systems modelling technique, Data Dependent Systems. The technique was applied to signals from strain gauges on a fully grouted resin roof bolt, and signals from accelerometers on the bolt head and roof rock used to examine the roof bolt's response to repeated blast loading. The damping ratios and natural frequencies of modes of vibration can reveal alteration of a bolt's dynamics due to deterioration of the roof rock, and can be used to identify incidence of instability in the roof bolt system. 892235 Uplift testing of model anchors Su, W; Fragaszy, R J J Geotech Engng Div ASCE VII4, N9, Sept 1988, P961-983 Model anchor tests were performed in sand to study uplift behaviour, difference between top and skin resistance, influence of anchor shape and size on uplift capacity, and the difference in the behaviour of anchors with and without free anchor length. Both deep and shallow failure were observed
© 1989 Pergamon Press plc. Reproduction not permitted
892218 Prediction of peak particle velocity and peak air pressure generated by buried explosion Gupta, R N; Pal Roy, P; Singh, B lnt J Min Geoi Engng V6. NI, March 1988, P15-26 Three sets of formulae, expressed as functions of dynamic elastic constants of rock, obtained from density, longitudinal and shear wave velocities, and some design parameters involved in a buried explosion, are explicitly derived to predict peak particle velocity (PPV) and peak air pressure (PAP). Separate equations are derived to estimate PPV and PAP for inside, outside and at the boundary of the crater zone. The formulae were applied to 7 rock types, including diorite, granite and limestone, and then verified using data from in situ controlled blasting.
892219 Scientific approach to blast design. The influence of rock characteristics Rorke, A J Quarry Manage Oct 1988. P33-42 Successful blast design produces a diggable rock pile with minimum adverse environmental impact. The outcome of the blast depends upon the nature and characteristics of the rock, the real performance of the explosive within the rock, and blast design. Rock characterisation in terms of dynamic and static properties, effects of dynamic properties on fragmentation and heave, influence of rock structure, and effects of explosives performance on blast qualities have been analysed using computer simulations.
892220 Model study of crater blasting Fourney, W L; Dick, R D; Simha, K R Y Rock Mech Rock Engng V21, N3, July-Sept 1988, P183-205 Cratering experiments to date have been unable to quantify the effects of stemming on cratering and fragmentation. To clarify this, small scale model tests using granite, Hydrostone (gypsum based), and plexiglass blocks were carried out. Results indicate that fracture and fragmentation in single hole crater blasting situations are not influenced by stemming. Radial cracks are formed before the crater formation process begins, and the crater initiates at the borehole wall and propagates to the surface. Crater formation is heavily dependent on stress wave effects and only in a minor way on borehole pressurisation. Scale effects and limitations on extrapolation of small scale model tests are discussed.
892221 Getting the right 'bang' in the right place at the right time Martin, D Tunn Tunnlg V20. N9, Sept 1988, P32-37 The non-electric detonator represented a significant development in blasting technology. It has no blast effect since it is confined in a tube, is not sensitive to electric currents and is safer than traditional detonators. Another improvement in blasting was development of emulite, a water-in-oil emulsion, which is safer than nitroglycerine, has good rock breaking qualities, and is stable and water resistant. The smooth blasting technique is outlined and charging equipment described.
892222 Some suitable patterns of drilling and controlled blasting in the surrounding of four hydroelectric projects in India Gupta, R N: Pal Roy, P: Bagchi, A; Singh, R B: Singh, B Proc Symposium on Rock Mechanics and Power Plants, Madrid, 12-16 Sept 1988 VI. P49-56. Publ Rotterdam: A A Balkema, 1988 Prevention of blasting damage to existing structures or part completed projects is essential. Although geological parameters are set, borehole, burden, spacing, stemming, explosive type, and delay firing may be varied to minimise vibration, often at little or no extra cost. A critical analysis of blast design is presented, and application of its results to four major projects described.
892223 Longer rounds to improve tunnelling and development work Niklasson, B; Holmberg, R; Olsson, K; Schorling, S Proc Tunnelling '88, London, 18-21 April 1988 P213-221. Publ London: IMM, 1988 Work in a Swedish iron ore mine where change to large scale sublevel caving is being investigated is presented. Development of the drilling, blasting, scaling, loading, and transport processes in drift driving is described. Currently available drill rigs are found to be inefficient in pulling drill rounds 7m long. Effects on setting times for other operations in the cycle, blast design, and performance are considered.
Crushing and grinding 892224 Fundamental study of dry and wet grinding from the viewpoint of breaking strength Kanda, Y; Abe, Y; Yamaguchi, M; Endo, C Powder Technol V56, NI. Sept 1988, P57-62 Differences between wet and dry grinding have been studied. Bending tests were conducted on a glass material to investigate the quantitative effects of water on bending strength, crack propagation and the relationship between strength and number of cracks. Results show crack length is greater in water than in air, bending strength is lower in water than in air, and a wet grinding process is useful from point of view of strength of solids.
Machine excavation 892225 Roadheader cutting heads and picks Hurt, K G Colliery Guard V236, N9, Sept 1988, P332-335 As roadheaders have become larger and more sophisticated, cutterhead design has assumed increasing importance. Design trends are illustrated, with the change from radial to point or forward attack picks, improvements in pick layout to minimise vibration, and water jet assistance being considered. Limits to roadheader cutting ability are also discussed.
892226 Criteria for selecting a boom-type roadheader Schneider, H Min Mag Sept 1988, P183-187 The simplest classification of boom type roadheaders is by weight. This allows the engineer to obtain information on approximate price on a weight basis, size, and field of applications. The areas where roadheaders in the 5 weight classes
~! 1989 Pergamon Press plc. Reproduction not permitted
79A suggested have been applied are described. Three types of cutter head, in line, transverse, and cylindrical, advancing and articulated booms, and water jet assisted cutting, and their particular advantages are considered. Finally, special project requirements are examined.
Rock and Soil Reinforcement and Support
892231 Ten thousand anchorages in rock Barley, A D Ground Engng V21, N7, Oct 1988, P24-35 Use of ground anchors in chalk, mudstones, siltstones, shales and marls, and sandstones is considered using data from a variety of projects. For each rock type, development of construction method, ultimate bond, failure mechanism and working anchorages are considered, and a data table presented showing SPT values, fixed length, diameter, working bond, test bond, ultimate bond and F value for a number of sites. 892232 Stability of rock masses reinforced by passive, fully-grouted rock bolts Sharma, K G; Pande, G N Int J Rock Mech Min Sci V25, NS, Oct 1988, P273-285
See also: 892407 892227 Rock support Hoek, E; Wood, D F Min Mug Oct 1988. P282-287 A comprehensive evaluation of support requirements for underground hard rock mining is presented. Suggested rock support for conditions from good quality rock under low in situ stress to poor quality rock in shear zones is illustrated in tabular form. Active rock reinforcement, the range of bolts, dowels, bars and anchors, and passive support, mesh, straps, shotcrete and steel sets, are illustrated, and areas for their application discussed.
Bolts and anchors 892228 Australian mining - the role of roofbolting Banford, C R Colliery Guard V236, N9, Sept 1988, P315-318 As open pit mine reserves have become depleted, deep longwall mining has assumed increasing importance in Australia. The historical development of roofbolting in Australian pits and currently used methods and equipment are described. Factors which must be taken into account to adapt these practices to British conditions are examined. The role of the strata control group at ACIRL is also described. 892229 Roofbolting for retreat Eaton, J Colliery Guard V236, N9, Sept 1988, P320-322 Key areas where cost reductions are possible in British coal mines are outlined. The mechanism of roadway stability and influences of rock mass strength, stress level and orientation, and size and shape of roadway are considered. The use of active roofbolt support for longwall mining with retreat as a specific economy measure is described. 892230 Ten thousand anchorages in rock Barley, A D Ground Engng V21, N6, Sept 1988. P20-29 An overview of the use, effectiveness and development of rock anchorages, based on data from 10,000 cases, is presented. Fixed anchor dimensions, drilling and flushing methods, borehole alignment, methods to ensure grout tightness of a fixed anchor length, grout and grout mixing, and anchor tendons are considered.
The behaviour of a jointed rock mass with fully grouted passive reinforcements is simulated using the equivalent material approach, which distributes the influence of rock joints as well as rock bolts throughout the rock mass. Properties of the rock material, joint sets and reinforcement sets are discussed, and a finite element program developed to analyse the problem of a jointed rock slope and compute factors of safety against collapse. It is shown that the dilatancy of rock joints and the orientation of rock bolts are the most important factors in determining the effectiveness of passive, fully grouted rock bolts. 892233 Estimation of gain in pillar strength due to bolting: technical note Sheorey, P R lnt J Rock Mecli Min Sci V25, NS, Oct 1988. P321-326 Wilson's theory to define pillar strength in terms of the vertical stress developed in the failed rock zone has been extended to obtain the probable strength of bolted pillars which are intact before bolting. The approach assumes that bolting becomes fully effective only when the pillar is about to fail. Estimation of the triaxial parameter and strength is outlined. 892234 Response of grouted roof bolts to blast loading: technical note Otuonye, F O lnt J Rock Mech Min Sci V25, NS. Oct 1988. P345-349 The transfer of stresses from rock to rock bolt and the bolt's response during blast loading have been studied, using a time series and systems modelling technique, Data Dependent Systems. The technique was applied to signals from strain gauges on a fully grouted resin roof bolt, and signals from accelerometers on the bolt head and roof rock used to examine the roof bolt's response to repeated blast loading. The damping ratios and natural frequencies of modes of vibration can reveal alteration of a bolt's dynamics due to deterioration of the roof rock, and can be used to identify incidence of instability in the roof bolt system. 892235 Uplift testing of model anchors Su, W; Fragaszy, R J J Geotech Engng Div ASCE VII4, N9, Sept 1988, P961-983 Model anchor tests were performed in sand to study uplift behaviour, difference between top and skin resistance, influence of anchor shape and size on uplift capacity, and the difference in the behaviour of anchors with and without free anchor length. Both deep and shallow failure were observed
© 1989 Pergamon Press plc. Reproduction not permitted