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Automated pressuremeter for offshore soil testing at water depths to 300m
234A
934215 Automated pressuremeter for offshore soil testing at water depths to 300m Korneshchuk, D G; Teryaev, N G; Okko, O Proc 3rd International Symposium on Field Measurements in Geomechanics, Oslo, 9-11 September 1991 V1, P315-322. Publ Rotterdam." A A Balkema, 1991 An instrument based on the pneumatic marine pressuremeter is described. It requires no hydraulic or electronic connections and shipboard collection of test data is relatively simple. Testing procedures and interpretation to obtain values of deformation and strength properties, friction angle, cohesion, and coefficient of consolidation are outlined. Examples of its use are presented and possible improvements suggested.
934219 Integrated interpretation of marine engineering geological and geophysical data on the principles of expert system technology Kovalevsky, E V; Kharchenko, V I Geophys Prospect V40, 3/8, Nov 1992, P909-923 An expert system under development for indcntification of seafloor sub-bottom soils is described. Seismic and electrical site investigation data for each point are transformed to give a subjective probability of that soil being of a particular type. Local geotechnical (mainly drilling) data, extrapolated by means of diffusion of the initial membership function distribution, also provide a similar set of probabilities~ The fuzzy information is aggregated and decisions made by Bayesian summation. An example of the principles is illustrated.
Presentation and interpretation of data See also: 934040 934216 Statistical modelling of spatial variability of undrained strength Ravi, V Can Geotech J V29, NS, Oct 1992, P721-729 Both natural soil deposits and man-made soil structures possess inherent variability in values of undrained strength with depth. A number of predictive models based on autoregressive moving average models exist. An improved modelling procedure is proposed which removes the trend in the spatial series of depth vs Cu and can estimate undrained strength at a given depth better than other models in this class. A computer program has been developed to fit the model in conjunction with a standard nonlinear least squares routine. The program is rapidly convergent. Its application to case studies is shown.
934220 Location of subsurface targets in geophysical data using neural networks Poulton, M M; Sternberg, B K; Glass, C E Geophysics V57, N12, Dec 1992, P1534-1544 The ability of 5 neural network paradigms to estimate the offset, depth, and conductivity-area product of a buried conductive target has been examined. The basic principles of the neural networks are outlined. Of particular interest are how the different networks handle the data, field data obtained over the same target used for training but with a different background geoelectrical model, and how well the networks can extrapolate for both input and output parameters. Neural networks are no panacea for unsolvable problems, but in some cases may provide a faster, more accurate, or more flexible solution than traditional procedures.
934217 Optimal estimation of crack-strike MacBeth, C; Yardley, G S Geophys Prospect V40, N8, Nov 1992, P849-872
934221 Estimating autoeovariance of in-situ soil properties DeGroot, D J; Baecher, G B J Geotech Engng Div ASCE V119, N1, Jan 1993, P147-166
Analysis of shear wave splitting is one method of gaining information on crack strike and crack density of reservoir rocks. The dual source cumulative (DCT) technique, common in processing VSP and surface data, is demonstrated using synthetic seismograms to examine its ability to determine depth variation of crack strike. A complementary alternative technique, the dual-independent source-geophone technique (DIT), is also applied to see whether it provides any additional benefits.
Soil properties tend to show a spatial correlation structure. A procedure to estimate this structure, based on the method of Maximum Likelihood, principally applied in econometrics, is presented. The power and simplicity of ML estimators of spatially variable soil properties and their superiority over present estimation techniques are demonstrated theoretically and with data from a practical geotechnical project. The ML techniques are easily incorporated in computerized data acquisition systems.
934218 Multipurameter geophysical logging at the Yava lead deposit: a statistical approach Cinq-Mars, A; Mwenifumbo, C J; Killen, P G; Chouteau, M Geophys Prospect V40, N8, Nov 1992, P829-848 Statistical analysis of multiparameter data from a sandstone lead deposit is presented. The spectral gamma-gamma ratio log (SGG ratio) is seen to be the most effective for characterising the disseminated sulphide mineralisation. Principal Component Analysis shows that IP logs respond both to the clay minerals in the sandstone and disseminated galena. PCA also confirms that S G G ratio and density are related to lead content and that lithological variations can be delineated using natural radioactivity and resistivity. Zinc content of the deposit was only poorly resolved by geophysics.
934222 Use of computers in the engineering geology of the urban renewal of London's docklands Howland, A F Q J Engug Geol V25, N4, 1992, P257-267 Development of London Docklands has provided a large amount of geotechnical data which is now available for application in future engineering projects. To store, manipulate and retrieve this information, a PC database, GEODASY, was devised which can hold stratigraphic data from a projected 10000 boreholes plus field and laboratory test data. Output can be in tabular or graphical form. System development is outlined and input and output formats illustrated.
© 1993 Pergamon Press Ltd. Reproduction not permitted
934215 Automated pressuremeter for offshore soil testing at water depths to 300m Korneshchuk, D G; Teryaev, N G; Okko, O Proc 3rd International Symposium on Field Measurements in Geomechanics, Oslo, 9-11 September 1991 V1, P315-322. Publ Rotterdam." A A Balkema, 1991 An instrument based on the pneumatic marine pressuremeter is described. It requires no hydraulic or electronic connections and shipboard collection of test data is relatively simple. Testing procedures and interpretation to obtain values of deformation and strength properties, friction angle, cohesion, and coefficient of consolidation are outlined. Examples of its use are presented and possible improvements suggested.
934219 Integrated interpretation of marine engineering geological and geophysical data on the principles of expert system technology Kovalevsky, E V; Kharchenko, V I Geophys Prospect V40, 3/8, Nov 1992, P909-923 An expert system under development for indcntification of seafloor sub-bottom soils is described. Seismic and electrical site investigation data for each point are transformed to give a subjective probability of that soil being of a particular type. Local geotechnical (mainly drilling) data, extrapolated by means of diffusion of the initial membership function distribution, also provide a similar set of probabilities~ The fuzzy information is aggregated and decisions made by Bayesian summation. An example of the principles is illustrated.
Presentation and interpretation of data See also: 934040 934216 Statistical modelling of spatial variability of undrained strength Ravi, V Can Geotech J V29, NS, Oct 1992, P721-729 Both natural soil deposits and man-made soil structures possess inherent variability in values of undrained strength with depth. A number of predictive models based on autoregressive moving average models exist. An improved modelling procedure is proposed which removes the trend in the spatial series of depth vs Cu and can estimate undrained strength at a given depth better than other models in this class. A computer program has been developed to fit the model in conjunction with a standard nonlinear least squares routine. The program is rapidly convergent. Its application to case studies is shown.
934220 Location of subsurface targets in geophysical data using neural networks Poulton, M M; Sternberg, B K; Glass, C E Geophysics V57, N12, Dec 1992, P1534-1544 The ability of 5 neural network paradigms to estimate the offset, depth, and conductivity-area product of a buried conductive target has been examined. The basic principles of the neural networks are outlined. Of particular interest are how the different networks handle the data, field data obtained over the same target used for training but with a different background geoelectrical model, and how well the networks can extrapolate for both input and output parameters. Neural networks are no panacea for unsolvable problems, but in some cases may provide a faster, more accurate, or more flexible solution than traditional procedures.
934217 Optimal estimation of crack-strike MacBeth, C; Yardley, G S Geophys Prospect V40, N8, Nov 1992, P849-872
934221 Estimating autoeovariance of in-situ soil properties DeGroot, D J; Baecher, G B J Geotech Engng Div ASCE V119, N1, Jan 1993, P147-166
Analysis of shear wave splitting is one method of gaining information on crack strike and crack density of reservoir rocks. The dual source cumulative (DCT) technique, common in processing VSP and surface data, is demonstrated using synthetic seismograms to examine its ability to determine depth variation of crack strike. A complementary alternative technique, the dual-independent source-geophone technique (DIT), is also applied to see whether it provides any additional benefits.
Soil properties tend to show a spatial correlation structure. A procedure to estimate this structure, based on the method of Maximum Likelihood, principally applied in econometrics, is presented. The power and simplicity of ML estimators of spatially variable soil properties and their superiority over present estimation techniques are demonstrated theoretically and with data from a practical geotechnical project. The ML techniques are easily incorporated in computerized data acquisition systems.
934218 Multipurameter geophysical logging at the Yava lead deposit: a statistical approach Cinq-Mars, A; Mwenifumbo, C J; Killen, P G; Chouteau, M Geophys Prospect V40, N8, Nov 1992, P829-848 Statistical analysis of multiparameter data from a sandstone lead deposit is presented. The spectral gamma-gamma ratio log (SGG ratio) is seen to be the most effective for characterising the disseminated sulphide mineralisation. Principal Component Analysis shows that IP logs respond both to the clay minerals in the sandstone and disseminated galena. PCA also confirms that S G G ratio and density are related to lead content and that lithological variations can be delineated using natural radioactivity and resistivity. Zinc content of the deposit was only poorly resolved by geophysics.
934222 Use of computers in the engineering geology of the urban renewal of London's docklands Howland, A F Q J Engug Geol V25, N4, 1992, P257-267 Development of London Docklands has provided a large amount of geotechnical data which is now available for application in future engineering projects. To store, manipulate and retrieve this information, a PC database, GEODASY, was devised which can hold stratigraphic data from a projected 10000 boreholes plus field and laboratory test data. Output can be in tabular or graphical form. System development is outlined and input and output formats illustrated.
© 1993 Pergamon Press Ltd. Reproduction not permitted