- Email: [email protected]
Estimating grade differentials from drilling results on new gold properties
23A 891180 G~otomography in the study of rockbm'sts and selsmicity in mines Young, R P Pro¢ 2ad lnterutional Sympadam of Rockbarsts and
Seismieity in Mines, Mianeapolls, 8-10 Jane 1988, Keynote Presentations P122-138. Pubi Minneapolis: University of Minnesota, 1988 Geotomography, a technique where seismic or acoustic waves are used to produce digital images based on velocity or attenuation of signals, can be used to interpret the state of large volumes of rock between traditional point measurements. Three techniques are briefly described: transform, algebraic reconstruction, and direct inversion. Factors affecting velocity and attenuation of seismic waves in rock masses are examined. Applications such as data acquisition for mine planning, identification of anomalous zones ahead of mining, and monitoring using sequential tomography are discussed.
by up to 60% despite all cones conforming to the European standard. Dependent on the cone, negative or positive sleeve friction was measured in clays, and pore pressures measured behind the tip can be up to 30% lower than those measured at the tip. Correction for pore pressure and temperature shift effects reduces variations in cone resistance but has little effect on sleeve friction. 891185
Piezoconc: improvements in soil investigation (In French) Parez, L, Fauriel, R
Rev Fr Geotecb N44, 1988. P13-27
Borehole and core logging
The piezocone test, with a standard electric friction cone incorporating a pressure transducer, is relatively new. The state of the art in piezocone testing is described. Influences of filter position, penetration rate, and response time of the instrument are examined. A suitable calibration procedure is described. Methods of using the piezocone to obtain soil classification data, undrained shear strength of clays, liquefaction resistance of sands, and to forecast consolidation times are described.
891181
891186
Graphic presentation of discontinuities in rock cores (In
Estimating grade differentials from drilling results on new gold properties Krige, D G
French)
Clouet, A A
int Assoc Engng Geol Bull N37. April 1988. P107-112 A statistical study of the spacing of the discontinuities along cores from two dam sites was conducted. Cumulative curves were prepared, and it is shown that best statistical information is gained by examining lengths of broken and unbroken core rather than the whole core. Statistical information on discontinuity spacings and lengths of broken core was obtained. 891182
Percussion corer and extrusion device for unconsolidated sediments. Research method paper Parker, A; McCann, C
J Sediment Petrol V58, N4. July 1988. P752-753 A simple corer of a lm long PVC lined steel tube, for use in soils or sediments, is described. The cutting head is designed to minimise disturbance. Cores are extruded using a hydraulic pump, which allows precise control. 891183
Dilatometer tests in sands Lacasse, S; Lunne, T
Norw Geotech Inst Publ NITI, 1988.8P The application of the Marchetti flat dilatometer to control of compaction and determination of constrained modulus when a 15m deep sand deposit was vibrocompacted is described. Results indicate compaction was effective to at least 14m deep, and resulted in increase of horizontal in situ stress, resistance to compression, and effective friction angle. Constrained moduli evaluated from DMTs on a loose sand were in good agreement with those from screw plate tests and back analysis of settlement in silos. 891184 Laboratory and field evaluation of cone penetrometers Lunne, T; Eidsmoen, T; Gillespie, D; Howland, J D
Norw Geotech lnst Publ NI71, 1988, 13P Eight cone penetrometers were evaluated at three sites, to determine factors affecting accuracy, and improve repeatability and accuracy. Pore pressure and temperature zero shift influenced uncorrected cone resistance and sleeve friction. Magnitude of pore pressure was dependent on the location of the porous filter. Measured cone resistances varied
Proc APCOM 87, Johannesburg, 19-23 October 1987 V2. P31-41. Publ Johannesburg: SAIMM, 1987 When estimating grade differences between subdivisions using only borehole results, exaggerated differentials will be obtained if data solely from within each subarea are used. Smoothing is required to minimise exaggeration. Kriging using the Iognormal-de Wijsian model is demonstrated to be advantageous for several data sets when indicating the spatial structure for the boreholes, even when they are far apart. 891187 ln-situ deformability and fracturation studies by use of
Probex-I borehole dilatumeter Scoble, M J; Cullen, M; Barclay, R; Carter, M A
Proc CARE 88 (Conference on Applied Rock Engineering), Newcastle, 6-8 January 1988 P203-211. Publ London: IMM, 1988 Details of the testing procedures of the Probex-I and its use as a dilatometer and impression packer are presented. It was used to determine the extent of fracturing and modulus reduction due to confined underground blasting, and the level of deformation and fracturing in stope pillars. The dilatometer is shown to be field reliable although deformation modulus results are sensitive to mode of operation. The fracture impression technique is accurate and reliable. 891188
Evaluation of sample quality by thin-wall sampling tube Horiuchi, T; Eiki, A; Funahashi, M
Proc Eighth Asian Regional Conference on Soil Mechmdcs and Foundation Engineering, Kyoto, 20-24 July 1987 VI. P4144. Publ Japan: Japanese Society for Soil Mechanics and Foundation Engineering, 1987 Thin wall tube samples of soft clayey soil were taken using hammer driven open, stationary open, and hydraulic piston samplers. 8cm by 3.5cm diameter specimens were taken from within the tube samples, and subjected to unconfined compression tests, with failure stress and strain and modulus of deformability being measured. The parameter modulus of deformability:failure strength less than 50 was taken as indicative of disturbed soil. The volumes of disturbed soil in the samples taken by each method are discussed.
© 1989 Pergamon Press pie. Reproduction not permitted
Seismieity in Mines, Mianeapolls, 8-10 Jane 1988, Keynote Presentations P122-138. Pubi Minneapolis: University of Minnesota, 1988 Geotomography, a technique where seismic or acoustic waves are used to produce digital images based on velocity or attenuation of signals, can be used to interpret the state of large volumes of rock between traditional point measurements. Three techniques are briefly described: transform, algebraic reconstruction, and direct inversion. Factors affecting velocity and attenuation of seismic waves in rock masses are examined. Applications such as data acquisition for mine planning, identification of anomalous zones ahead of mining, and monitoring using sequential tomography are discussed.
by up to 60% despite all cones conforming to the European standard. Dependent on the cone, negative or positive sleeve friction was measured in clays, and pore pressures measured behind the tip can be up to 30% lower than those measured at the tip. Correction for pore pressure and temperature shift effects reduces variations in cone resistance but has little effect on sleeve friction. 891185
Piezoconc: improvements in soil investigation (In French) Parez, L, Fauriel, R
Rev Fr Geotecb N44, 1988. P13-27
Borehole and core logging
The piezocone test, with a standard electric friction cone incorporating a pressure transducer, is relatively new. The state of the art in piezocone testing is described. Influences of filter position, penetration rate, and response time of the instrument are examined. A suitable calibration procedure is described. Methods of using the piezocone to obtain soil classification data, undrained shear strength of clays, liquefaction resistance of sands, and to forecast consolidation times are described.
891181
891186
Graphic presentation of discontinuities in rock cores (In
Estimating grade differentials from drilling results on new gold properties Krige, D G
French)
Clouet, A A
int Assoc Engng Geol Bull N37. April 1988. P107-112 A statistical study of the spacing of the discontinuities along cores from two dam sites was conducted. Cumulative curves were prepared, and it is shown that best statistical information is gained by examining lengths of broken and unbroken core rather than the whole core. Statistical information on discontinuity spacings and lengths of broken core was obtained. 891182
Percussion corer and extrusion device for unconsolidated sediments. Research method paper Parker, A; McCann, C
J Sediment Petrol V58, N4. July 1988. P752-753 A simple corer of a lm long PVC lined steel tube, for use in soils or sediments, is described. The cutting head is designed to minimise disturbance. Cores are extruded using a hydraulic pump, which allows precise control. 891183
Dilatometer tests in sands Lacasse, S; Lunne, T
Norw Geotech Inst Publ NITI, 1988.8P The application of the Marchetti flat dilatometer to control of compaction and determination of constrained modulus when a 15m deep sand deposit was vibrocompacted is described. Results indicate compaction was effective to at least 14m deep, and resulted in increase of horizontal in situ stress, resistance to compression, and effective friction angle. Constrained moduli evaluated from DMTs on a loose sand were in good agreement with those from screw plate tests and back analysis of settlement in silos. 891184 Laboratory and field evaluation of cone penetrometers Lunne, T; Eidsmoen, T; Gillespie, D; Howland, J D
Norw Geotech lnst Publ NI71, 1988, 13P Eight cone penetrometers were evaluated at three sites, to determine factors affecting accuracy, and improve repeatability and accuracy. Pore pressure and temperature zero shift influenced uncorrected cone resistance and sleeve friction. Magnitude of pore pressure was dependent on the location of the porous filter. Measured cone resistances varied
Proc APCOM 87, Johannesburg, 19-23 October 1987 V2. P31-41. Publ Johannesburg: SAIMM, 1987 When estimating grade differences between subdivisions using only borehole results, exaggerated differentials will be obtained if data solely from within each subarea are used. Smoothing is required to minimise exaggeration. Kriging using the Iognormal-de Wijsian model is demonstrated to be advantageous for several data sets when indicating the spatial structure for the boreholes, even when they are far apart. 891187 ln-situ deformability and fracturation studies by use of
Probex-I borehole dilatumeter Scoble, M J; Cullen, M; Barclay, R; Carter, M A
Proc CARE 88 (Conference on Applied Rock Engineering), Newcastle, 6-8 January 1988 P203-211. Publ London: IMM, 1988 Details of the testing procedures of the Probex-I and its use as a dilatometer and impression packer are presented. It was used to determine the extent of fracturing and modulus reduction due to confined underground blasting, and the level of deformation and fracturing in stope pillars. The dilatometer is shown to be field reliable although deformation modulus results are sensitive to mode of operation. The fracture impression technique is accurate and reliable. 891188
Evaluation of sample quality by thin-wall sampling tube Horiuchi, T; Eiki, A; Funahashi, M
Proc Eighth Asian Regional Conference on Soil Mechmdcs and Foundation Engineering, Kyoto, 20-24 July 1987 VI. P4144. Publ Japan: Japanese Society for Soil Mechanics and Foundation Engineering, 1987 Thin wall tube samples of soft clayey soil were taken using hammer driven open, stationary open, and hydraulic piston samplers. 8cm by 3.5cm diameter specimens were taken from within the tube samples, and subjected to unconfined compression tests, with failure stress and strain and modulus of deformability being measured. The parameter modulus of deformability:failure strength less than 50 was taken as indicative of disturbed soil. The volumes of disturbed soil in the samples taken by each method are discussed.
© 1989 Pergamon Press pie. Reproduction not permitted