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Horizon control holds key to automation: Part two
2~4A of strain level. On this basis a criterion is proposed for determining the pressure amplitude for load-unload tests in sands, whose adoption reduces the variations in shear modulus from successive loops at different initial pressures. 925241 EXPANSOL, a new apparatus for expansive soil studies (In French) Flavigny, E; Magnan, D; Muschotti, E Proc lOth European Conference on Soil l~lechanics and Foundation Engineering, Florence, 26-30 May 1991 VI, P8790. Publ Rotterdam: A A Balkema, 1991 EXPANSOL, a new pressuremeter device, has been developed for use in expansive or moisture sensitive soils. It has two chambers, one mounted vertically above the other. The first is, in effect, a normal pressuremeter, the second has an additional system which allows introduction of water and measurement of free swell or swelling pressure. The instrument is illustrated, method of use described, and results of its application presented.
Presentation and interpretation of data See also: 925021, 925044 925242 Use of a Geographic Information System as a tool in mineral exploration Hummer, R W C I M Bull V85, N957, Feb 1992. P67-71 The application of a GIS in mineral exploration is illustrated with reference to the Eskay Creek area of British Columbia. The concepts of the system, data entry, analysis and manipulation (including map merging and overlay production), and output are described. The ability to perform complex searches of large and diverse data sets to indicate target areas for mining is illustrated. Data from geological, geophysical, geochemical,and mineral deposit sources can be combined and analysed in relatively short times. 925243 Application of diffraction tomography to fracture detection Tura, M A C; Johnson, L R; Majer, E L; Peterson, J E Geophysics V57, N2, Feb 1992, P245-257 The conventional back-propagation method and a new quadratic programming method incorporating constraints have been applied to crosshole seismic data to detect fractures in a rock mass. The Born approximation is used for linearisation of the inverse problem. The data used are from the well characterised Grimsel test site in Switzerland. Images obtained show possible fracture zones which agree well, at the boundaries of the region examined, with fractures indicated from borehole cores. The quadratic programming method is much slower than the back-propagation method, but yields high resolution images where constraints can be imposed. 925244 Integrity of pseudo-sonic transforms Worthington, P F Sci Drilling V2, N5, 1991, P279-286 Pseudo-sonic transforms are algorithms used to construct equivalent sonic data at a corresponding scale from measurements of other physical properties, and to generate sonic logs for boreholes where no sonic tool was run. The value of the pseudo-sonic data is governed by quality of input data and
accuracy of the transform. Relative effectiveness of these transforms is evaluated and shortcomings identified and rectified where possible.
Suggested testing methods and standards 925245 Interpretation of plate load test data Boyle, W J Int J Rock Mech Min Sci 1129, N2, March 1992, P133-141 The ISRM suggested method for determining in situ deformability of rock masses uses the plate load test. Previous work indicates there is potential for large errors in interpreting plate load data, with values of deformability returned being greater than Young's modulus measured on intact rock. A finite element simulation of the plate load test is presented, with the aim of assessing effects ofjointing and excavation geometry on the results of the test. Based on this work, a modification is proposed to the ISRM suggested method data interpretation, which also allows calculation of Poisson's ratio. 925246 Suggested Method for Blast Vibration Monitoring International Society for Rock Mechanics Commission on Testing Methods Int J Rock Mech Min Sci V29, N2, March 1992, P143.156 A suggested method is presented which can be divided into three main sections. In the first, the characteristics of blast excitations are discussed: ground motion; the transient nature of blast motion; sinusoidal approximation; dominant frequencies; propagation effects; and air over-pressures. Measurement techniques and instrumentation are then described. The evaluation of these measurements is considered in the final section. Structural response classes are defined, statistical analysis of data discussed, and frequency control of structural response examined. Comparisons are made between blast and environmental effects and of response of restrained structures and rock masses.
Monitoring rock and soil mass performance See also: 925037 925247 Horizon control holds key to automation: Part two Mowrey, G L Coal 1187, N1, Jan 1992, P47-51 Interface detection techniques not described in the earlier work are outlined. An infrared imaging video system to monitor temperatures associated with the coal-rock cutting interface is one approach. Optical methods based on a sensor mounted on the cutter head to monitor changes in rock surface reflectance or video monitoring of colour change of rock or dust are also under development. Change in motor current to cut rock or continuous X-ray fluorescence monitoring have also been examined. The only commercially operational system is one based on monitoring of natural gamma radiation. 925248 Design and performance of the Imperial College instrumented pile Bond, A J; Jardine, R J; Dalton, J C P Geotech Test J II14, N4, Dec 1991, P413-424 Design, calibration, and performance of instrumentation developed for research into behaviour of displacement piles in clays and sands are described. The 7m long, 102mm diameter
© 1992 Pergamon Press Ltd. Reproduction not permitted
Presentation and interpretation of data See also: 925021, 925044 925242 Use of a Geographic Information System as a tool in mineral exploration Hummer, R W C I M Bull V85, N957, Feb 1992. P67-71 The application of a GIS in mineral exploration is illustrated with reference to the Eskay Creek area of British Columbia. The concepts of the system, data entry, analysis and manipulation (including map merging and overlay production), and output are described. The ability to perform complex searches of large and diverse data sets to indicate target areas for mining is illustrated. Data from geological, geophysical, geochemical,and mineral deposit sources can be combined and analysed in relatively short times. 925243 Application of diffraction tomography to fracture detection Tura, M A C; Johnson, L R; Majer, E L; Peterson, J E Geophysics V57, N2, Feb 1992, P245-257 The conventional back-propagation method and a new quadratic programming method incorporating constraints have been applied to crosshole seismic data to detect fractures in a rock mass. The Born approximation is used for linearisation of the inverse problem. The data used are from the well characterised Grimsel test site in Switzerland. Images obtained show possible fracture zones which agree well, at the boundaries of the region examined, with fractures indicated from borehole cores. The quadratic programming method is much slower than the back-propagation method, but yields high resolution images where constraints can be imposed. 925244 Integrity of pseudo-sonic transforms Worthington, P F Sci Drilling V2, N5, 1991, P279-286 Pseudo-sonic transforms are algorithms used to construct equivalent sonic data at a corresponding scale from measurements of other physical properties, and to generate sonic logs for boreholes where no sonic tool was run. The value of the pseudo-sonic data is governed by quality of input data and
accuracy of the transform. Relative effectiveness of these transforms is evaluated and shortcomings identified and rectified where possible.
Suggested testing methods and standards 925245 Interpretation of plate load test data Boyle, W J Int J Rock Mech Min Sci 1129, N2, March 1992, P133-141 The ISRM suggested method for determining in situ deformability of rock masses uses the plate load test. Previous work indicates there is potential for large errors in interpreting plate load data, with values of deformability returned being greater than Young's modulus measured on intact rock. A finite element simulation of the plate load test is presented, with the aim of assessing effects ofjointing and excavation geometry on the results of the test. Based on this work, a modification is proposed to the ISRM suggested method data interpretation, which also allows calculation of Poisson's ratio. 925246 Suggested Method for Blast Vibration Monitoring International Society for Rock Mechanics Commission on Testing Methods Int J Rock Mech Min Sci V29, N2, March 1992, P143.156 A suggested method is presented which can be divided into three main sections. In the first, the characteristics of blast excitations are discussed: ground motion; the transient nature of blast motion; sinusoidal approximation; dominant frequencies; propagation effects; and air over-pressures. Measurement techniques and instrumentation are then described. The evaluation of these measurements is considered in the final section. Structural response classes are defined, statistical analysis of data discussed, and frequency control of structural response examined. Comparisons are made between blast and environmental effects and of response of restrained structures and rock masses.
Monitoring rock and soil mass performance See also: 925037 925247 Horizon control holds key to automation: Part two Mowrey, G L Coal 1187, N1, Jan 1992, P47-51 Interface detection techniques not described in the earlier work are outlined. An infrared imaging video system to monitor temperatures associated with the coal-rock cutting interface is one approach. Optical methods based on a sensor mounted on the cutter head to monitor changes in rock surface reflectance or video monitoring of colour change of rock or dust are also under development. Change in motor current to cut rock or continuous X-ray fluorescence monitoring have also been examined. The only commercially operational system is one based on monitoring of natural gamma radiation. 925248 Design and performance of the Imperial College instrumented pile Bond, A J; Jardine, R J; Dalton, J C P Geotech Test J II14, N4, Dec 1991, P413-424 Design, calibration, and performance of instrumentation developed for research into behaviour of displacement piles in clays and sands are described. The 7m long, 102mm diameter
© 1992 Pergamon Press Ltd. Reproduction not permitted