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Rotary drilling prediction
303A external databases. An example to demonstrate the system capability and handling of uncertainty by fuzzy logic mechanisms is presented. 9152% Use of an expert system in site investigation Toll, D G; Attewell, P B Proc 6th ZnrernationcJ Congress Znternu~ionaZAssociation of Engineering Geology, Amstrrdom, 6-10 August 1990 VI, P767-773. Pub1 Rotterdam: A A Balkema, 1990 An expert system for site investigation should include geologicaljgeotechnical and structural interactions plus components considering financial and contractual/legal details, which cannot be disregarded in the real world. Interpretation of the state of the ground by interpolation between limited data sets, usually boreholes, is the severe test for knowledge based systems. Interrogation and interpretation at different levels of complexity is necessary, from broad classification to qualitative description to quantitative analysis. An example of such a system is described. 915297 Computer assisted stope design Tatiya, R R Rot 2Zst Znrernatiorurl Symposium on AppZication of Computers and Operations Research in the Mine& Zndusrry, Las Vegas, 27 February-2 March 1989 P.506~520. Publ
and concrete. Fracturing is quasi static (minutes to hours) and gas, dust, flyrock, and vibration are absent. The mechanism of fracture, stress fields generated, estimation of crack length, and required borehole spacing are examined on a theoretical basis. Laboratory and field tests using the Aconex RBC are described. Areas with potential for RBC application are discussed.
Rock fracture under dynamic stresses 915300 Optimization of impact bit spacing using ultrasonic wave transit time measurements Inyang, H I; Pitt, J M Rock Mechanics Contributions and ChaZlenges: Z’roc 3Zst US SympoSum, Go&n, 18-20 June 1990 P519-526. Pub1
Rotterdam: A A Balkema, 1990 Bit spacing is a critical feature in design of tools for rock breaking which apply impact loads. A NDT technique to estimate the size of fractured zones around impact points, using ultrasonic methods to measure the extent of damage, has been developed. Tests were carried out on blocks of two granites using single impact bits. Use of results to optimise bit spacing for impact and impact/drag bit excavators is discussed.
Littleton: AIME. 1989 Algorithms have been developed to model sublevel, down-thehole, and cut and fill stoping. They may be applied to design and analyse economic performance of one or more stopes in a continuous orebody. Each individual stope is first considered, followed by design and economic assessment of the composite pattern. Stope design aspects only are presented. 915298 MINSIM - the MINe SIMulator Lavrencic, J B Proc 2Zsr Zn~ernational Symposium on AppZication of Computers and Operations Research in & Mine& In&try, Las Vega, 27 February-2 March 1989 P653-661. Publ
Littleton: AZME, 1989 Mineral deposits generally have irregular geology. The questions of what production can be expected and where and with what equipment must be considered. The MINSIM simulator is a structured computer program which can be tailored to fit conditions of a wide range of underground and surface mines. It considers a network of working places connected by paths of varying quality, and exploited by working groups using mining equipment. MINSIM evaluates optimum sequencing of operations. The kernel, subroutines, and structure of MINSIM are described.
Rock Breakage and Excavation 915299 Use of rock breaking compounds (RBC) in mining and civil engineering - laboratory and field investigations Dcy, U K; Gupta, R N; Ghose, A K J Min MetaZ Fuel V38, N9. Sept 1990. P209-215, 227 RBCs, expansive cements mixed with water and poured into drillholes of appropriate dimensions, can generate expansive stresses in excess of 30MPa, which will fracture most rocks 0
Drilling See also: 915253, 915255
915301
Production drilling technologies Zaburunov, S A Engng Min J V192, N2. Feb 1991, P29-37
Developments in drilling technology may not be immediately visible but often have great importance. Dry drilling in a hard rock mine in Ontario gave faster penetration rate than wet drilling, because of improved flushing and lower drill bit wear. Low maintenance, non-mechanical seals have been developed to keep dust make to acceptable levels. Drill bits with improved flushing have been designed and advances made in drilling automation and monitoring. Economics of good drilling practice are outlined.
915302 Rotary drilling prediction Wijk, G Znt J Rock Mech Min Sci V28. Nl, Jan 1991, P35-42 The Stamp Test (ibid, V26, 1989, P37-44) has been presented for rock drillability classification in percussion drilling. In both percussion and rotary drilling the rock destruction mechanism is the same, although the respective rates at which the buttons penetrate the rock are metres and millimetres per second. It should therefore be possible to develop a drillability classification for rotary drilling on a similar basis as the Stamp Test. A direct physical model is proposed to replace the dimensional analysis of the Stamp Test in order to accommodate the case of thrust force too low for rotary bit buttons to break the rock. This yields predictions of the accuracy required in practical cases. A simple model of rotary drilling economics is defined.
1991 Pergamon Press plc. Reproduction
not permitted
and concrete. Fracturing is quasi static (minutes to hours) and gas, dust, flyrock, and vibration are absent. The mechanism of fracture, stress fields generated, estimation of crack length, and required borehole spacing are examined on a theoretical basis. Laboratory and field tests using the Aconex RBC are described. Areas with potential for RBC application are discussed.
Rock fracture under dynamic stresses 915300 Optimization of impact bit spacing using ultrasonic wave transit time measurements Inyang, H I; Pitt, J M Rock Mechanics Contributions and ChaZlenges: Z’roc 3Zst US SympoSum, Go&n, 18-20 June 1990 P519-526. Pub1
Rotterdam: A A Balkema, 1990 Bit spacing is a critical feature in design of tools for rock breaking which apply impact loads. A NDT technique to estimate the size of fractured zones around impact points, using ultrasonic methods to measure the extent of damage, has been developed. Tests were carried out on blocks of two granites using single impact bits. Use of results to optimise bit spacing for impact and impact/drag bit excavators is discussed.
Littleton: AIME. 1989 Algorithms have been developed to model sublevel, down-thehole, and cut and fill stoping. They may be applied to design and analyse economic performance of one or more stopes in a continuous orebody. Each individual stope is first considered, followed by design and economic assessment of the composite pattern. Stope design aspects only are presented. 915298 MINSIM - the MINe SIMulator Lavrencic, J B Proc 2Zsr Zn~ernational Symposium on AppZication of Computers and Operations Research in & Mine& In&try, Las Vega, 27 February-2 March 1989 P653-661. Publ
Littleton: AZME, 1989 Mineral deposits generally have irregular geology. The questions of what production can be expected and where and with what equipment must be considered. The MINSIM simulator is a structured computer program which can be tailored to fit conditions of a wide range of underground and surface mines. It considers a network of working places connected by paths of varying quality, and exploited by working groups using mining equipment. MINSIM evaluates optimum sequencing of operations. The kernel, subroutines, and structure of MINSIM are described.
Rock Breakage and Excavation 915299 Use of rock breaking compounds (RBC) in mining and civil engineering - laboratory and field investigations Dcy, U K; Gupta, R N; Ghose, A K J Min MetaZ Fuel V38, N9. Sept 1990. P209-215, 227 RBCs, expansive cements mixed with water and poured into drillholes of appropriate dimensions, can generate expansive stresses in excess of 30MPa, which will fracture most rocks 0
Drilling See also: 915253, 915255
915301
Production drilling technologies Zaburunov, S A Engng Min J V192, N2. Feb 1991, P29-37
Developments in drilling technology may not be immediately visible but often have great importance. Dry drilling in a hard rock mine in Ontario gave faster penetration rate than wet drilling, because of improved flushing and lower drill bit wear. Low maintenance, non-mechanical seals have been developed to keep dust make to acceptable levels. Drill bits with improved flushing have been designed and advances made in drilling automation and monitoring. Economics of good drilling practice are outlined.
915302 Rotary drilling prediction Wijk, G Znt J Rock Mech Min Sci V28. Nl, Jan 1991, P35-42 The Stamp Test (ibid, V26, 1989, P37-44) has been presented for rock drillability classification in percussion drilling. In both percussion and rotary drilling the rock destruction mechanism is the same, although the respective rates at which the buttons penetrate the rock are metres and millimetres per second. It should therefore be possible to develop a drillability classification for rotary drilling on a similar basis as the Stamp Test. A direct physical model is proposed to replace the dimensional analysis of the Stamp Test in order to accommodate the case of thrust force too low for rotary bit buttons to break the rock. This yields predictions of the accuracy required in practical cases. A simple model of rotary drilling economics is defined.
1991 Pergamon Press plc. Reproduction
not permitted