- Email: [email protected]
Experiences with new hydraulic rock drilling techniques at the Hanging Lake Project, Glenwood Canyon, Colorado, USA
240A
Design methods 934262 Uncertainties in the analysis of rock structures (In German) Schubert, P Felsbau II10, N4, Nov 1992, P191-195 Uncertainty in stability analysis in rock engineering has a number of contributory factors: the geological prediction model; the mechanical properties of the rock mass; the primary stress field; and the capabilities of the calculation model. Stability analysis is thus a multiparameter problem, with each parameter introducing new uncertainties. An example is illustrated which emphasises the systematic combination of parameters and estimated probability of parameter combinations. 934263 Ground control models for coal mine design Peng, S S J Min Metal Fuels V40, N5/6, May-June 1992, P169-178 Four ground control computer programs developed for design of underground coal mines are discussed. PILLAR can be used to design both stiff and yielding pillars in room and pillar workings. ROOFBOLT is a combined BE-FE method for analysis of bolt-reinforced ground. DEPOWS is for longwall shield design. CISPM, based on the influence function method, is for prediction of surface subsidence. Examples of use of each program are shown. 934264 Kinematic indeterminacy as basis for the determination of optimum mining procedures Howell, G C; Kirsten, H A D Proc International Symposium on Rock Support, Sudbury, 1619 June 1992 P139-148. Publ Rotterdam: ,4 /4 Balkema, 1992 The stability of mining/civil engineering structures is dependent on the integrity and load carrying capacity of the remaining broken rock and its interaction with applied support. A uniform criterion for performance evaluation of various mining procedures is proposed, based on the hypothesis that differences is mining problems are related to particular boundary conditions, not fundamental physicomechanical differences. Broken ground is subject basically to indeterminate displacements and such indeterminacy is, in theory, treatable by numerical analysis. A unified performance criterion, related to the degree to which kinematic indeterminacy is present, can be established for design purposes.
Rock Breakage and Excavation Drilling 934265 D.T.H. Drilling - the preferred option Bennett, A Geodrilling N76, Nov 1992, P12-14 Comparison is presented between downhole, rotary, and percussion (drifter) drilling of rocks. DTH drilling is shown to have advantages in ability to drill in almost all rocks, from soft to very hard, to produce cleaner, straighter holes, to have lower costs, high output capability and penetration rate, to drill a wide range of hole diameters, and to be quieter than percussion drilling.
934266 Drilling of rock bolt-holes in confined mine spaces (In German) Dahle, O Gluckauf V128, N8, Aug 1992, P616-618 The Flexi-Driil drill rig is presented, which was developed to allow drilling of long bolt holes from confined mine spaces. Its design is based on earlier experience with flexible drill strings. Adequate thrust force and torque can be applied to achieve penetration rates of 1.3m/min for 36mm diameter holes in low strength rocks. Drilling heads with diamond cutting edges have been developed for use in harder and more abrasive rocks. 934267 Dome-shaped PDC cutters drill harder rock effectively Moran, D P Oil Gas J ;I90, NSO, Dec 1992, P46-49 Data are presented from a number of wells drilled in Queen and Grayburg formation carbonate rocks. Bit records, welibore log data, and laboratory tests on core samples have been analysed. PDC bits with dome headed cutters effectively drilled rocks with compressive strengths 16-82% greater than the typical (flat) PDC bit applications in the area. The convex cutter shows good impact resistance, cuttings removal, heat dissipation, and wear resistance. 934268 New water-based muds for tertiary shale control Reid, P I; Minton, R C S P E Drilling Engng V7, N4, Dec 1992, P237-240 Environmental problems limit the application of oil-based drilling muds to control reactive shales in the North Sea. Laboratory and field evaluation of a series of water muds by BP is outlined. They are based on the original KC1/partiaily hydrolized polyacrylamide formulation plus cationic starch. Levels of inhibition are further increased by additions of polyglycerol or a phosphate salt and polyglycerol. Performance of the most inhibitive is close to that of an oil-based mud. 934269 Development of hydrodynamic-model-based air-drilling design procedures Tian, S; Adewumi, M A S P E Drilling Engng V7, N4, Dec 1992, P241-246 A comprehensive study of air drilling hydraulics has been undertaken and used as a basis for systematic design of air drilling procedures. Models for air flow in the drillstring, air flow in the bit nozzles, and cuttings transport are combined. Design procedures to predict standpipe pressure, maximum well depth, and optimum air flow rate are presented. Practical applications of these procedures are illustrated. 934270 Experiences with new hydraulic rock drilling techniques at the Hanging Lake Project, Glenwood Canyon, Colorado, USA Hamrin, H Proc TUNCON '92, Design and Construction of Tunnels, Masern, Lesotho, September 1992 P23-27. Publ Yeoville: South African National Council on Tunnelling, 1992 A new generation of hydraulic rock drill capable of 50% higher performance than other drills has been developed. Control systems have also been developed and refined and the result is the Rocket Boomer tunnel drill rig from Atlas Copco. Experiences in using the Rocket Boomer in excavation of
© 1993 Pergamon Press Ltd. Reproduction not permitted
241A highway tunnels in quartz, diorite, and fractured granite are described. The improved drill power results in a practical drilling output increase of 25%.
on fracture mechanics principles is presented to calculate fracture surface energy, which allows comparison of energy required to create the new surface with explosive energy input.
Blasting
934275 Explosion phenomenology in jointed rocks - new insights Heuze, F E; Butkovich, T R; Walton, O R; Maddix, D M
See also: 934324, 934406
Proe 7th I S R M lnternafonal Congress on Rock Mechanics,
934271 Vibration control in the use of explosives (In Italian and
Eu#sh) Piovano, G Gallerie V14, N38, 1992, P27-35 Blast, structure, and ground details all influence the stress and vibration levels imposed on a building by the detonation of an explosive. Of these, only ground conditions are effectively unalterable. Two approaches are proposed for blast vibration control. The first, which is straightforward, is planning in line with statutory limits. The second, which is more complex and expensive but may allow more efficient blasting, starts with dynamic analysis of the structure, and, having established acceptable levels at this point, works backwards to determine explosive charge parameters.
934272 Damage in rock under explosive loading: implementation in DYNA2D of a TCK model Sanchidrian, J A; Pesquero, J M; Garbayo, E Int d Surf Min V6, N3, I992, P109-114 Rock fragmentation is a primary objective of blasting. The TCK damage mechanics model of rock (Taylor, Chen, and Kuszmanl, 1986) is presented and implemented in the finite element code DYNA2D (Hallquist, 1988) to simulate explosive detonation. Results are presented in the form of charts of pressure isolines, damage parameter distribution, and radial stress as a function of time. The need for much more experimental evidence to allow calibration of the simulation is noted.
934273 Burden, spacing and borehole diameter at rock blasting Rustan, R A lnt J Surf Min V6, N3, 1992, P141-149 Statistical analysis is presented of data from 100 open pit and underground mines, which indicates that the relation between burden and blasthole diameter follows a power law. The linear relation given in many publications is valid only over a narrow range of diameter. Burden in underground mines is consistently relatively lower than in surface mines, due to greater confinement during blasting, higher ore densities, and greater demand for well fragmented ore. The formulae presented, which give no indication of fragmentation, are intended as preliminary blast design tools.
934274 Analysis of rock fragmentation in bench blasting using digital image processing Farmer, I W; Kemeny, J M; McDoniei, C Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V2, P1037-1042. Publ Rotterdam: A A Balkema, 1991 Digital image processing techniques used to determine size distribution of fragmented rocks before and after blasting are described. Several techniques are demonstrated, based on spherical, cubical, minimum elliptical, and average elliptical assumptions. Size distributions from image processing are in good agreement with those from sieving. A procedure based
Aachen, 16-20 September 1991 V2, P1043-1048. Publ Rotterdam: A A Balkema, 1991 Hard rock masses are rarely continuous and the presence of discontinuities controls the propagation of ground shock and kinematics of subsequent movement associated with high energy explosions. The shortcomings of continuum models to describe these phenomena are outlined. The DIBS (Discrete Interaction Block System) discrete element model, developed to simulate the dynamics of discontinuous media, is presented. It is illustrated modelling ground movement around a generic contained nuclear explosion. 934276 Correlation of powder factor with physical rock properties and rotary drill performance in Turkish surface coal mines Muftuoglu, Y V; Pasmehmetoglu, A G; Karpuz, C Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V2, P1049-1052. Publ Rotterdam: A A Balkema, 1991 Diggability, drillability, and blastability have been investigated at many Turkish open pit coal mines. Correlations have been examined between powder factor for overburden blasting and various physical properties of many different types of rock. Promising correlation is seen between powder factor and UCS, tensile strength, density, and P wave velocity. The Rock Quality Index (Leighton et al, 1982), determined from monitoring of blasthole drill performance, is found to a most useful indicator of required powder factor.
Machine excavation See also: 934442 934277 Operating experience with impact rippers in the drivage of gate roads at the Monopol colliery (In German) Kremer, M Gluckanf V128, N3, March 1992, P165-170 Impact rippers are well established for driving coal haulage roads at the Monopol colliery. Three designs are in use, which differ in the position of the impact ripper head in relation to the road axis, and thus require different loading machines. Hard rocks are blasted to maintain advance rates, and a drilling rig can be mounted on the ripper for this purpose. Under normal conditions, a lm advance can be achieved in 2.5-3h. Costs are given.
934278 New selective-cut road-heading machine technology at Ruhrkole (In German) Roesch, M Gluckauf V128, N12, Dec 1992, P923-931 Two new selective cut roadheaders are described. Their main developments from earlier models are improvements to machine kinematics and cutting technology, use of the slow cutting drive, use of a new spraying method, electrification of all drives, and testing of a performance monitoring system. Their performance is compared to that of the machines
© 1993 Pergamon Press Ltd. Reproduction not permitted
Design methods 934262 Uncertainties in the analysis of rock structures (In German) Schubert, P Felsbau II10, N4, Nov 1992, P191-195 Uncertainty in stability analysis in rock engineering has a number of contributory factors: the geological prediction model; the mechanical properties of the rock mass; the primary stress field; and the capabilities of the calculation model. Stability analysis is thus a multiparameter problem, with each parameter introducing new uncertainties. An example is illustrated which emphasises the systematic combination of parameters and estimated probability of parameter combinations. 934263 Ground control models for coal mine design Peng, S S J Min Metal Fuels V40, N5/6, May-June 1992, P169-178 Four ground control computer programs developed for design of underground coal mines are discussed. PILLAR can be used to design both stiff and yielding pillars in room and pillar workings. ROOFBOLT is a combined BE-FE method for analysis of bolt-reinforced ground. DEPOWS is for longwall shield design. CISPM, based on the influence function method, is for prediction of surface subsidence. Examples of use of each program are shown. 934264 Kinematic indeterminacy as basis for the determination of optimum mining procedures Howell, G C; Kirsten, H A D Proc International Symposium on Rock Support, Sudbury, 1619 June 1992 P139-148. Publ Rotterdam: ,4 /4 Balkema, 1992 The stability of mining/civil engineering structures is dependent on the integrity and load carrying capacity of the remaining broken rock and its interaction with applied support. A uniform criterion for performance evaluation of various mining procedures is proposed, based on the hypothesis that differences is mining problems are related to particular boundary conditions, not fundamental physicomechanical differences. Broken ground is subject basically to indeterminate displacements and such indeterminacy is, in theory, treatable by numerical analysis. A unified performance criterion, related to the degree to which kinematic indeterminacy is present, can be established for design purposes.
Rock Breakage and Excavation Drilling 934265 D.T.H. Drilling - the preferred option Bennett, A Geodrilling N76, Nov 1992, P12-14 Comparison is presented between downhole, rotary, and percussion (drifter) drilling of rocks. DTH drilling is shown to have advantages in ability to drill in almost all rocks, from soft to very hard, to produce cleaner, straighter holes, to have lower costs, high output capability and penetration rate, to drill a wide range of hole diameters, and to be quieter than percussion drilling.
934266 Drilling of rock bolt-holes in confined mine spaces (In German) Dahle, O Gluckauf V128, N8, Aug 1992, P616-618 The Flexi-Driil drill rig is presented, which was developed to allow drilling of long bolt holes from confined mine spaces. Its design is based on earlier experience with flexible drill strings. Adequate thrust force and torque can be applied to achieve penetration rates of 1.3m/min for 36mm diameter holes in low strength rocks. Drilling heads with diamond cutting edges have been developed for use in harder and more abrasive rocks. 934267 Dome-shaped PDC cutters drill harder rock effectively Moran, D P Oil Gas J ;I90, NSO, Dec 1992, P46-49 Data are presented from a number of wells drilled in Queen and Grayburg formation carbonate rocks. Bit records, welibore log data, and laboratory tests on core samples have been analysed. PDC bits with dome headed cutters effectively drilled rocks with compressive strengths 16-82% greater than the typical (flat) PDC bit applications in the area. The convex cutter shows good impact resistance, cuttings removal, heat dissipation, and wear resistance. 934268 New water-based muds for tertiary shale control Reid, P I; Minton, R C S P E Drilling Engng V7, N4, Dec 1992, P237-240 Environmental problems limit the application of oil-based drilling muds to control reactive shales in the North Sea. Laboratory and field evaluation of a series of water muds by BP is outlined. They are based on the original KC1/partiaily hydrolized polyacrylamide formulation plus cationic starch. Levels of inhibition are further increased by additions of polyglycerol or a phosphate salt and polyglycerol. Performance of the most inhibitive is close to that of an oil-based mud. 934269 Development of hydrodynamic-model-based air-drilling design procedures Tian, S; Adewumi, M A S P E Drilling Engng V7, N4, Dec 1992, P241-246 A comprehensive study of air drilling hydraulics has been undertaken and used as a basis for systematic design of air drilling procedures. Models for air flow in the drillstring, air flow in the bit nozzles, and cuttings transport are combined. Design procedures to predict standpipe pressure, maximum well depth, and optimum air flow rate are presented. Practical applications of these procedures are illustrated. 934270 Experiences with new hydraulic rock drilling techniques at the Hanging Lake Project, Glenwood Canyon, Colorado, USA Hamrin, H Proc TUNCON '92, Design and Construction of Tunnels, Masern, Lesotho, September 1992 P23-27. Publ Yeoville: South African National Council on Tunnelling, 1992 A new generation of hydraulic rock drill capable of 50% higher performance than other drills has been developed. Control systems have also been developed and refined and the result is the Rocket Boomer tunnel drill rig from Atlas Copco. Experiences in using the Rocket Boomer in excavation of
© 1993 Pergamon Press Ltd. Reproduction not permitted
241A highway tunnels in quartz, diorite, and fractured granite are described. The improved drill power results in a practical drilling output increase of 25%.
on fracture mechanics principles is presented to calculate fracture surface energy, which allows comparison of energy required to create the new surface with explosive energy input.
Blasting
934275 Explosion phenomenology in jointed rocks - new insights Heuze, F E; Butkovich, T R; Walton, O R; Maddix, D M
See also: 934324, 934406
Proe 7th I S R M lnternafonal Congress on Rock Mechanics,
934271 Vibration control in the use of explosives (In Italian and
Eu#sh) Piovano, G Gallerie V14, N38, 1992, P27-35 Blast, structure, and ground details all influence the stress and vibration levels imposed on a building by the detonation of an explosive. Of these, only ground conditions are effectively unalterable. Two approaches are proposed for blast vibration control. The first, which is straightforward, is planning in line with statutory limits. The second, which is more complex and expensive but may allow more efficient blasting, starts with dynamic analysis of the structure, and, having established acceptable levels at this point, works backwards to determine explosive charge parameters.
934272 Damage in rock under explosive loading: implementation in DYNA2D of a TCK model Sanchidrian, J A; Pesquero, J M; Garbayo, E Int d Surf Min V6, N3, I992, P109-114 Rock fragmentation is a primary objective of blasting. The TCK damage mechanics model of rock (Taylor, Chen, and Kuszmanl, 1986) is presented and implemented in the finite element code DYNA2D (Hallquist, 1988) to simulate explosive detonation. Results are presented in the form of charts of pressure isolines, damage parameter distribution, and radial stress as a function of time. The need for much more experimental evidence to allow calibration of the simulation is noted.
934273 Burden, spacing and borehole diameter at rock blasting Rustan, R A lnt J Surf Min V6, N3, 1992, P141-149 Statistical analysis is presented of data from 100 open pit and underground mines, which indicates that the relation between burden and blasthole diameter follows a power law. The linear relation given in many publications is valid only over a narrow range of diameter. Burden in underground mines is consistently relatively lower than in surface mines, due to greater confinement during blasting, higher ore densities, and greater demand for well fragmented ore. The formulae presented, which give no indication of fragmentation, are intended as preliminary blast design tools.
934274 Analysis of rock fragmentation in bench blasting using digital image processing Farmer, I W; Kemeny, J M; McDoniei, C Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V2, P1037-1042. Publ Rotterdam: A A Balkema, 1991 Digital image processing techniques used to determine size distribution of fragmented rocks before and after blasting are described. Several techniques are demonstrated, based on spherical, cubical, minimum elliptical, and average elliptical assumptions. Size distributions from image processing are in good agreement with those from sieving. A procedure based
Aachen, 16-20 September 1991 V2, P1043-1048. Publ Rotterdam: A A Balkema, 1991 Hard rock masses are rarely continuous and the presence of discontinuities controls the propagation of ground shock and kinematics of subsequent movement associated with high energy explosions. The shortcomings of continuum models to describe these phenomena are outlined. The DIBS (Discrete Interaction Block System) discrete element model, developed to simulate the dynamics of discontinuous media, is presented. It is illustrated modelling ground movement around a generic contained nuclear explosion. 934276 Correlation of powder factor with physical rock properties and rotary drill performance in Turkish surface coal mines Muftuoglu, Y V; Pasmehmetoglu, A G; Karpuz, C Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V2, P1049-1052. Publ Rotterdam: A A Balkema, 1991 Diggability, drillability, and blastability have been investigated at many Turkish open pit coal mines. Correlations have been examined between powder factor for overburden blasting and various physical properties of many different types of rock. Promising correlation is seen between powder factor and UCS, tensile strength, density, and P wave velocity. The Rock Quality Index (Leighton et al, 1982), determined from monitoring of blasthole drill performance, is found to a most useful indicator of required powder factor.
Machine excavation See also: 934442 934277 Operating experience with impact rippers in the drivage of gate roads at the Monopol colliery (In German) Kremer, M Gluckanf V128, N3, March 1992, P165-170 Impact rippers are well established for driving coal haulage roads at the Monopol colliery. Three designs are in use, which differ in the position of the impact ripper head in relation to the road axis, and thus require different loading machines. Hard rocks are blasted to maintain advance rates, and a drilling rig can be mounted on the ripper for this purpose. Under normal conditions, a lm advance can be achieved in 2.5-3h. Costs are given.
934278 New selective-cut road-heading machine technology at Ruhrkole (In German) Roesch, M Gluckauf V128, N12, Dec 1992, P923-931 Two new selective cut roadheaders are described. Their main developments from earlier models are improvements to machine kinematics and cutting technology, use of the slow cutting drive, use of a new spraying method, electrification of all drives, and testing of a performance monitoring system. Their performance is compared to that of the machines
© 1993 Pergamon Press Ltd. Reproduction not permitted