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Light sectioning of underground excavations
212A
SITE INVESTIGATIONS:MAPPING
956162 The effect of sample disturbance on laboratory properties of Lac do Bonnet granite C. D. Martin 8c B. Stimpsoa, Canadian Geotechnical Joumul, 31(5), 1994, pp 692-702. Laboratory properties of Lac du Bonnet granite samples collected at depths ranging from near-surface to 1000 m were established. The laboratory properties indicated that either the in situ properties were changing with depth or the samples were changing with depth. Comparison of P-wave velocities in the samples and in situ confirmed the latter, i.e., sample disturbance was a.lTecting the laboratory properties. The strength of the damaged samples indicated the sample disturbance affected the cohesion of the material, not the frictional properties, and that the cohesion loss cannot be accounted for, by applying a confining stress. Sample disturbance started to affect the laboratory properties when the maximum far-field in situ stress exceeded about 10% of the unconfined compression strength. (Authors)
SITE INVESTIGATION AND FIELD OBSERVATION General 956163 Precious metals geology and exploration in Spain: progress and questions R. Castroviejo, Chronique de la Recherche Miniere, 516, 1994, pp 3-24. A summary review is given of the precious metal deposit types, classified and described in the framework of Iberian geology, as well as of their exploration and mining potential with a special emphasis on the hypogene gold deposits of the Hercynian Hesperian Massif and the epithermal gold deposits of the Neogene calcalkaline volcanic province of SE Spain. (from Author)
Remote sensing and photographic techniques 956164 Increasing range of tasks for rmderwater acoustic positioning R. Binks, Geomatics Info Magazine, 9(4), 1995, pp 47-50. Underwater acoustic positioning now plays a key role in every aspect of offshore oil and gas exploitation, from the positioning of seismic streamers, in exploration drilling, in field development, construction, production and maintenance. This article looks at just two examples of underwater positioning at work in the Far East: on China’s Liuhua Field and on the dynamically positioned construction vessel ‘Pacific Constructor’. Finally, the role of acoustics in establishing an underwater GIS is examined. (from Author) 956165 GPS for beight determination A. H. Dodson, Survey Review, 33(256), 1995, pp 66-76. The Global Positioning System (GPS) has considerable potential for providing high accuracy height measurement over considerable distances. At long range it has higher precision than conventional levelling and, at all but the shortest ranges, it is much more efficient. However, GPS levelling has its problems, regarding for example geoid determination, atmospheric propagation delay, and ocean loading effects. This paper reviews the state of GPS levelling
with specific reference to both engineering and large scale environmental applications. (Author) 956166 Studies of the GPS technique on engineering surveying applications using tbe wild GPS system 200 E. Mok & J. So, Survey Review, 33(256), 1995, pp 115-129. A series of field tests were carried out at Chek Lap Kok - the new Hone Kong airnort site - to investieate the suitabilitv of applying GPS &&ques for engineerin;! surveying appfications. Results of the field tests are uresented with discussions. (Authors) 1
956167 Remote sensing of seismic vibrations by laser Doppler interferometry A. J. Bemi, Geophysics, 59(12), 1994, pp 1856-1867. Geophones have been used as seismometers since the beginning of the seismic exploration industry. Analog transmission over multi-conductor cables has given way to field digitixation and telemetry using wire, optical fiber, radio waves, or transportation of cassettes. All of these have concentrated on improving the transmission of the data after detection by the geophone. In this paper, a different sensing method that uses a laser and an optical interferometer is investigated. The objective is to sense seismic particle motion by recovering the Doppler shift of a laser beam that is directed to various ground spots from a remote location. This paper presents results from two field tests using experimental, laser-based, data acquisition systems. In the first test, strong ground-roll vibrations were detected at an 800-m range by reflecting the beam directly from various terrain targets. The second test used a novel optical interferometer that cancelled turbulence noise. (from Author) 956168 Light sectioning of underground excavations & ThereIt & A. J. Beer, Survey Review, 33(256), 1995, pp - . The benefits of measuring open stope excavations, in order to determine potential ore dilution are significant in the current economic climate. Cambome School of Mines has developed a simple cost effective method of remote stope measurement utilizing light sectioning. The method uses a rotating focusable light source positioned in the stope, which is projected perpendicular to its axis of rotation, the image being captured by a 35 mm camera using a wide angle or ‘fish-eye’ lens. After distortion corrections, overbreak can be determined by direct comparison to designed profiles highlighting blast parameter inefficiencies. (Authors)
Structural and geotechnical mapping 956169 Command Area Development Programme in Rajasthan U. R. Mehta, Irrigation & Power Journal, 50(4), 1993, pp 147-180. The Rajasthan State Electricity Board is constructing gasbased coal-based thermal and small hydroprojects in the deserts of north-western Rajasthan. This area is characterised by highly undulating ground with unstable sand dunes, low rainfall and strong dust storms. Rock strata is not available to a great depth and the dune sands have low bearing capacities with higher settlement values. Construction of heavy structures with dynamic loadings on these sandy soils is a challenging task. In order to correctly assess the geotechnical properties of the soil and to ensure that the foundations do
SITE INVESTIGATIONS:MAPPING
956162 The effect of sample disturbance on laboratory properties of Lac do Bonnet granite C. D. Martin 8c B. Stimpsoa, Canadian Geotechnical Joumul, 31(5), 1994, pp 692-702. Laboratory properties of Lac du Bonnet granite samples collected at depths ranging from near-surface to 1000 m were established. The laboratory properties indicated that either the in situ properties were changing with depth or the samples were changing with depth. Comparison of P-wave velocities in the samples and in situ confirmed the latter, i.e., sample disturbance was a.lTecting the laboratory properties. The strength of the damaged samples indicated the sample disturbance affected the cohesion of the material, not the frictional properties, and that the cohesion loss cannot be accounted for, by applying a confining stress. Sample disturbance started to affect the laboratory properties when the maximum far-field in situ stress exceeded about 10% of the unconfined compression strength. (Authors)
SITE INVESTIGATION AND FIELD OBSERVATION General 956163 Precious metals geology and exploration in Spain: progress and questions R. Castroviejo, Chronique de la Recherche Miniere, 516, 1994, pp 3-24. A summary review is given of the precious metal deposit types, classified and described in the framework of Iberian geology, as well as of their exploration and mining potential with a special emphasis on the hypogene gold deposits of the Hercynian Hesperian Massif and the epithermal gold deposits of the Neogene calcalkaline volcanic province of SE Spain. (from Author)
Remote sensing and photographic techniques 956164 Increasing range of tasks for rmderwater acoustic positioning R. Binks, Geomatics Info Magazine, 9(4), 1995, pp 47-50. Underwater acoustic positioning now plays a key role in every aspect of offshore oil and gas exploitation, from the positioning of seismic streamers, in exploration drilling, in field development, construction, production and maintenance. This article looks at just two examples of underwater positioning at work in the Far East: on China’s Liuhua Field and on the dynamically positioned construction vessel ‘Pacific Constructor’. Finally, the role of acoustics in establishing an underwater GIS is examined. (from Author) 956165 GPS for beight determination A. H. Dodson, Survey Review, 33(256), 1995, pp 66-76. The Global Positioning System (GPS) has considerable potential for providing high accuracy height measurement over considerable distances. At long range it has higher precision than conventional levelling and, at all but the shortest ranges, it is much more efficient. However, GPS levelling has its problems, regarding for example geoid determination, atmospheric propagation delay, and ocean loading effects. This paper reviews the state of GPS levelling
with specific reference to both engineering and large scale environmental applications. (Author) 956166 Studies of the GPS technique on engineering surveying applications using tbe wild GPS system 200 E. Mok & J. So, Survey Review, 33(256), 1995, pp 115-129. A series of field tests were carried out at Chek Lap Kok - the new Hone Kong airnort site - to investieate the suitabilitv of applying GPS &&ques for engineerin;! surveying appfications. Results of the field tests are uresented with discussions. (Authors) 1
956167 Remote sensing of seismic vibrations by laser Doppler interferometry A. J. Bemi, Geophysics, 59(12), 1994, pp 1856-1867. Geophones have been used as seismometers since the beginning of the seismic exploration industry. Analog transmission over multi-conductor cables has given way to field digitixation and telemetry using wire, optical fiber, radio waves, or transportation of cassettes. All of these have concentrated on improving the transmission of the data after detection by the geophone. In this paper, a different sensing method that uses a laser and an optical interferometer is investigated. The objective is to sense seismic particle motion by recovering the Doppler shift of a laser beam that is directed to various ground spots from a remote location. This paper presents results from two field tests using experimental, laser-based, data acquisition systems. In the first test, strong ground-roll vibrations were detected at an 800-m range by reflecting the beam directly from various terrain targets. The second test used a novel optical interferometer that cancelled turbulence noise. (from Author) 956168 Light sectioning of underground excavations & ThereIt & A. J. Beer, Survey Review, 33(256), 1995, pp - . The benefits of measuring open stope excavations, in order to determine potential ore dilution are significant in the current economic climate. Cambome School of Mines has developed a simple cost effective method of remote stope measurement utilizing light sectioning. The method uses a rotating focusable light source positioned in the stope, which is projected perpendicular to its axis of rotation, the image being captured by a 35 mm camera using a wide angle or ‘fish-eye’ lens. After distortion corrections, overbreak can be determined by direct comparison to designed profiles highlighting blast parameter inefficiencies. (Authors)
Structural and geotechnical mapping 956169 Command Area Development Programme in Rajasthan U. R. Mehta, Irrigation & Power Journal, 50(4), 1993, pp 147-180. The Rajasthan State Electricity Board is constructing gasbased coal-based thermal and small hydroprojects in the deserts of north-western Rajasthan. This area is characterised by highly undulating ground with unstable sand dunes, low rainfall and strong dust storms. Rock strata is not available to a great depth and the dune sands have low bearing capacities with higher settlement values. Construction of heavy structures with dynamic loadings on these sandy soils is a challenging task. In order to correctly assess the geotechnical properties of the soil and to ensure that the foundations do