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Techniques to investigate and remedy sinkholes
74A
SITE INVESTIGATION:GENERAL
conventional 'triaxiar compression configuration are contrasted with discrete failure tests conducted in the true triaxial cell, by means of the familiar yon Mises and extended 3-D Griffith criteria. Microseismic data and macroscopic observations from discrete failure tests performed within the true triaxial cell, are supportive of a brittle deformation mechanism involving stress-induced dilatant microcracks extending parallel to a2 and opening against ~3, progressively coalescing with increasing at to form a pervasive fault also oriented by the applied 3-D stress field (from Authors)
962208 Shear-wave velocity to evaluate in-situ state of Ottawa sand P. K. Robertson, S. Sasitharan, J. C. Cunning & D. C. Sego, Journal of Geotechnical Engineering - ASCE, 121(3), 1995, pp 262-273. This paper presents an experimental study of shear-wave velocity interpretation for clean Ottawa sand based on steady/critical state concepts. The results show that the large-strain behaviour of Ottawa sand can be estimated using shear-wave velocity measurements combined with a knowledge of the in situ effective stress. Knowledge of the state of a sand makes it is possible to estimate the boundary between either a contraetant or dilatant sand at large strains. (from Authors) 962209 On the go factor R. Szepeshazi, Periodica Polytechnica: Civil Engineering, 38(1), 1994, pp 127-135. After presenting the significance of the K0 factor the paper discusses some aspects of the formulae for the coefficient of earth pressure at rest, mainly the well-known Jaky's equation. An improvement for the critical Jaky's assumption is introduced and a modified /Co ...dO relationship is deduced. All the formulae originating from Jaky's idea and some other continuum mechanical or speculative equations are tested against 153 measured data. The original Jaky's equation, and the ones from Vierbiezky and Matsuoka-Sakakibara were found to be the best. (from Author) 962210 In sitn evaluation of go in eastern Canada clays K. K. Hamouche, S. Leroueil, M. Roy & A. J. Lutenegger, Canadian Geotechnical Journal, 32(4), 1995, pp 677-688. The horizontal effective stress in an overconsofidated clay deposit is often approximated from an estimate of the effective stress ratio, /Co, using the equation K ° = K0nc O C R ~. It is also generally cousidercd that the ~ parameter is approximately equal to sin dO'.For evaluating/Co in sensitive clays three differentin situ devices were used: the Cambridge self-boring pressuremeter, the flatdilatomcter, and hydraulic fracturing.The resultsshow that the differenttechniques give essentiallythe same K0 values. They also give K0 values larger than those expected, with an ~ parameter typically between 0.75 and 1.15. (from Authors) 962211 Fractographic features on joints of KTB drill cores (Bavaria, Germany) P. Bankwitz & E. Bankwitz, in: Fractography: fracture topography as a tool in fracture mechanics and stress analysis, ed M.S. Ameen, (Geological Society, London; Special Publication, 92), 1995, pp 39-58. Cores were used to estimate the orientation of the contemporary maximum horizontal stress by several methods in the KTB-field laboratory, including a study of core disking, borehole break-outs, cuttings and relaxation of the cores. Core disking surfaces are one type of coring-induced joint occurring in quasi-isotropic parts of the rock. The in situ stress orientation was determined from fractographic structures on common coring-induced fractures, which are present in all sections of the cores. This analysis is based on the symmetry of joint characteristics (3D shape and surface features of joint planes). The symmetry axes of these joint
features are related to the principal stress axes, which permits a determination of the orientation of the recent maximum and minimum horizontal stress axis (SH ~ Sh)- (from Authors)
962212 Borehole televiewer data analysis of Hole 504B from Legs 137 and 140 A. Kxammer, P. Pezard, P. K. H. Harvey & K. Fuchs, in: Proc., scientific results, ODP Leg 137/140, Costa Rica Rift, ed J. Erzinger & others, (ODP, Texas A&M University, College Station), 1995, pp 293-304. All BHTV data were analyzed for borehole breakouts and vertical fractures and compared with previous results from BHTV measurements at intermediate depth sections of this hole under consideration of ancillary information about the nearby tectonic setting. In addition, disturbed (logging after the end of drilling and circulation) and undisturbed (logging after reentry) temperature profiles through the complete borehole were used to estimate the temperature effect on borehole breakout and vertical fracture initiation. (from Authors) 962213 A practical geometry correction for interpreting pressuremeter tests in clay D. A. Shuttle & M. G. Jefferies, Geotechnique, 45(3), 1995, pp 549-553. The authors have repeated the core analyses of Houlsby & Carter (1993) using a public domain fmite element code which is substantially more accurate than that previously reported, thereby eliminating one possible error. Also, the analyses were extended to include the concentration phase of the selfbored pressuremeter (SBP) tests to minimize uncertainty in recovered properties. Like Houlsby & Carter, the authors use the numerical results to develop a finite geometry correction, but, unlike them, show that the correction factors recover the input soil parameters (referred to here as the 'true' parameters) within a defined certainty. Broadly, su can be recovered with an uncertainty of about ± 5% and Ir can be recovered to an uncertainty of about ± 20%. The accuracy with which O'ho can be recovered is approximately ± 2%. (from Authors) 962214 The performance of push-in spade cells installed in stiff clay M. D. Ryley & D. R. Carder, Geotechnique, 45(3), 1995, pp 533-539. In this study, a unique opportunity was available to install spade cellsin London clay horizontally from the shaft for the Heathrow Express trian tunnel and calibratethe instruments against known overburden stresses. Ceils were installed at differentdepths from boreholes drilledto 15 m from the shaft to ensure that verticalstresseswere outside the influence zone of the shaR, and therefore at overburden values. The overburden pressure at each spade cell location was then determined using the bulk density obtained from high-quality soil samples taken from an additional verticalborehole in the vicinity of the spade cells.(from Authors)
SITE INVESTIGATION AND FIELD OBSERVATION General 962215 Techniques to investigate and remedy sinkholes B. S. Qubain, E. J. Seksinsky & E. G. Aldin, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 341-347. The simple approach involved a visual inspection of the ground surface throughout the building and parking areas. Ground depressions were excavated, revealing substantial
SITE INVESTIGATIONS:REMOTE SENSING voids in the overburden. Once the cavities were exposed and the surrounding soft soils removed, the on-site soils were treated with lime and used as backfill. In contrast, the elaborate approach involved test borings with continuous standard penetration testing. At a third site locations were divided into three classifications depending on the severity of sinkhole activity, and a grouting program was developed to accomplish the needed improvement. At a third site a combination of elaborate and simple techniques was used. Electromagnetic profiling was utilized to delineate potential sinkholes. After excavation of the EM anomalies, geotextiles, rip rap, and lime treated on-site soil were installed to stabilize the sinkhole area. (from Authors)
962216 The use of geochemical methods in the investigation of hazardous waste sites in covered karst terrain T. Glover, J. Daniel & A. Lonergan, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 235-240. A suite of geochemical and statistcal data analysis tools has been used to define local hydrostratigraphy and flow regimes and augment limited drilling, core, and boring data in the interpretation of local areas of recharge, discharge, and interaquifer mixing and a better understanding of the general site characteristics. These tools include water type plots saturation indices, and elemental ratios. (from Authors)
962217 Selection of corridors for power transmission lines and highways through karst terranes E. H. Kastning, in: Karat geohazards: engineering and enviromnental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F~ Beck, (Balkema), 1995, pp 1951198. A major karat area is Currently under simultaneous consideration for routing of a 765-kilovolt power transmission line and several highways, including a major new interstate. For each project, several proposed alternative corridors cross the New River Valley drainage basin, including areas of karst in Montgomery, Craig, Giles, and Bland counties in Virginia and Monroe County in West Virginia. Karst has been mapped in the case of the power lines, albeit the level of detail is wanting. Karat has not been seriously considered during site evaluation for the proposed highways. Power-line and highway corridors coincide in some areas and not in others. Composite maps compiled by citizens action groups and this author indicate potentially threatening environmental problems in the region. (from Authors)
962218 Paleokarstic features in the Belgian carboniferous timestones - implications to engineering A. V. Y. Quinif & J. M. Charlet, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, B.F. Beck, (Balkema), 1995, pp 487-486. Proposes an efficient and comprehensive procedure locating Palaeokarst, defines a method of prospection appropriate to the type of karsts detected and describes an experiment applied to the 'Carriere du Milieu' terrain situated in the Tournaisis area. Both radon and temperature measurements were taken and interpreted by also taking into account a preliminary study of the morphostructures of the site. (from Authors)
75A
Remote sensing and photographic techniques 962219 Ground gamma radiation maps: processing of airborne, laboratory, and/n situ spectrometry data L. Rybach & G. F. Schwarz, First Break, 13(3), 1995, pp 97104. Maps of terrestrial gamma radiation, when converted to dose rate distribution, are indispensable for various purposes: they provide basic information for radiation biology and a welldocumented reference base for accident and emergency situations. Furthermore, they can aid geological mapping and/or prospecting for raw materials. Gamma radiation maps are especially needed on the scale of whole countries. Here, the methodology followed to establish a set of ground gamma radiation maps for Switzerland is summarized. (from Authors) 962220 Statistical interpretation of airborne gamma-ray spectrometric data, Esh E1 Milaha area, northern East Desert, Egypt S. I. Ruble, M. E. Mostafa & A. F. Khalil, Journal of African Earth Sciences, 19(1-2), 1994, pp 117-123. The technique of factor analysis has been applied to airborne gamma-ray spectrometric data. This analysis allows the geophysicists to perform a co-ordinated transformation of the three radioactive element concentrations (eU, eTh and K%), their ratios and the total count. The calculated factor scores may be used to spatially characterize different rock units in the area. (from Authors) 962221 Thermal emission from particulate surfaces: a comparison of scattering models with measured spectra J. E. Moersch & P. R. Christensen, Journal of Geophysical Research, 100(E4), 1995, pp 7465-7477. Emissivity spectra of particulate mineral samples are highly dependent on particle size when that size is comparable to the wavelength of light emitted (5-50 Inn for the midinfrared). Proper geologic interpretation of data from planetary infrared spectrometers will require that these particle size effects be well understood. To address this issue, samples of quartz powders were produced with narrow, well-characterized particle size distributions. Mean particle diameters in these samples ranged from 15 to 277 pro. Emission spectra of these powders allow the first detailed comparison of the complex spectral variations with particle size observed in laboratory data with the predictions of radiative transfer models. Four such models are considered. (from Authors) 962222 Remote sensing provides high-tech clues for mineral exploration C. H. Spencer, Earth Observation Magazine, 4(1), 1995, pp 21-23. This article provides an overview of how the high technology of satellite imagery can be used in the identification and location of minerals. A background on the instrumentation, in the form of a description of the major platforms and sensors available is given. This includes Landsat MSS and TM, SPOT and SAR. The relative advantages of using satellite imagery is covered with also an assessment of each sensor capability and the applications of mineral identication, exploration geology and geobotany. (after Author)
962223 Geotechnologies facilitate geologic mapping and field operations in Colombia J. M. Ellis, W. Narr, P. B. Goodwin & G. Perez, Earth Observation Magazine, 4(2), 1995, pp 18-21. This article provides an investigation into the use of Landsat TM, SPOT, SAR imagery and aerial photography as sources
SITE INVESTIGATION:GENERAL
conventional 'triaxiar compression configuration are contrasted with discrete failure tests conducted in the true triaxial cell, by means of the familiar yon Mises and extended 3-D Griffith criteria. Microseismic data and macroscopic observations from discrete failure tests performed within the true triaxial cell, are supportive of a brittle deformation mechanism involving stress-induced dilatant microcracks extending parallel to a2 and opening against ~3, progressively coalescing with increasing at to form a pervasive fault also oriented by the applied 3-D stress field (from Authors)
962208 Shear-wave velocity to evaluate in-situ state of Ottawa sand P. K. Robertson, S. Sasitharan, J. C. Cunning & D. C. Sego, Journal of Geotechnical Engineering - ASCE, 121(3), 1995, pp 262-273. This paper presents an experimental study of shear-wave velocity interpretation for clean Ottawa sand based on steady/critical state concepts. The results show that the large-strain behaviour of Ottawa sand can be estimated using shear-wave velocity measurements combined with a knowledge of the in situ effective stress. Knowledge of the state of a sand makes it is possible to estimate the boundary between either a contraetant or dilatant sand at large strains. (from Authors) 962209 On the go factor R. Szepeshazi, Periodica Polytechnica: Civil Engineering, 38(1), 1994, pp 127-135. After presenting the significance of the K0 factor the paper discusses some aspects of the formulae for the coefficient of earth pressure at rest, mainly the well-known Jaky's equation. An improvement for the critical Jaky's assumption is introduced and a modified /Co ...dO relationship is deduced. All the formulae originating from Jaky's idea and some other continuum mechanical or speculative equations are tested against 153 measured data. The original Jaky's equation, and the ones from Vierbiezky and Matsuoka-Sakakibara were found to be the best. (from Author) 962210 In sitn evaluation of go in eastern Canada clays K. K. Hamouche, S. Leroueil, M. Roy & A. J. Lutenegger, Canadian Geotechnical Journal, 32(4), 1995, pp 677-688. The horizontal effective stress in an overconsofidated clay deposit is often approximated from an estimate of the effective stress ratio, /Co, using the equation K ° = K0nc O C R ~. It is also generally cousidercd that the ~ parameter is approximately equal to sin dO'.For evaluating/Co in sensitive clays three differentin situ devices were used: the Cambridge self-boring pressuremeter, the flatdilatomcter, and hydraulic fracturing.The resultsshow that the differenttechniques give essentiallythe same K0 values. They also give K0 values larger than those expected, with an ~ parameter typically between 0.75 and 1.15. (from Authors) 962211 Fractographic features on joints of KTB drill cores (Bavaria, Germany) P. Bankwitz & E. Bankwitz, in: Fractography: fracture topography as a tool in fracture mechanics and stress analysis, ed M.S. Ameen, (Geological Society, London; Special Publication, 92), 1995, pp 39-58. Cores were used to estimate the orientation of the contemporary maximum horizontal stress by several methods in the KTB-field laboratory, including a study of core disking, borehole break-outs, cuttings and relaxation of the cores. Core disking surfaces are one type of coring-induced joint occurring in quasi-isotropic parts of the rock. The in situ stress orientation was determined from fractographic structures on common coring-induced fractures, which are present in all sections of the cores. This analysis is based on the symmetry of joint characteristics (3D shape and surface features of joint planes). The symmetry axes of these joint
features are related to the principal stress axes, which permits a determination of the orientation of the recent maximum and minimum horizontal stress axis (SH ~ Sh)- (from Authors)
962212 Borehole televiewer data analysis of Hole 504B from Legs 137 and 140 A. Kxammer, P. Pezard, P. K. H. Harvey & K. Fuchs, in: Proc., scientific results, ODP Leg 137/140, Costa Rica Rift, ed J. Erzinger & others, (ODP, Texas A&M University, College Station), 1995, pp 293-304. All BHTV data were analyzed for borehole breakouts and vertical fractures and compared with previous results from BHTV measurements at intermediate depth sections of this hole under consideration of ancillary information about the nearby tectonic setting. In addition, disturbed (logging after the end of drilling and circulation) and undisturbed (logging after reentry) temperature profiles through the complete borehole were used to estimate the temperature effect on borehole breakout and vertical fracture initiation. (from Authors) 962213 A practical geometry correction for interpreting pressuremeter tests in clay D. A. Shuttle & M. G. Jefferies, Geotechnique, 45(3), 1995, pp 549-553. The authors have repeated the core analyses of Houlsby & Carter (1993) using a public domain fmite element code which is substantially more accurate than that previously reported, thereby eliminating one possible error. Also, the analyses were extended to include the concentration phase of the selfbored pressuremeter (SBP) tests to minimize uncertainty in recovered properties. Like Houlsby & Carter, the authors use the numerical results to develop a finite geometry correction, but, unlike them, show that the correction factors recover the input soil parameters (referred to here as the 'true' parameters) within a defined certainty. Broadly, su can be recovered with an uncertainty of about ± 5% and Ir can be recovered to an uncertainty of about ± 20%. The accuracy with which O'ho can be recovered is approximately ± 2%. (from Authors) 962214 The performance of push-in spade cells installed in stiff clay M. D. Ryley & D. R. Carder, Geotechnique, 45(3), 1995, pp 533-539. In this study, a unique opportunity was available to install spade cellsin London clay horizontally from the shaft for the Heathrow Express trian tunnel and calibratethe instruments against known overburden stresses. Ceils were installed at differentdepths from boreholes drilledto 15 m from the shaft to ensure that verticalstresseswere outside the influence zone of the shaR, and therefore at overburden values. The overburden pressure at each spade cell location was then determined using the bulk density obtained from high-quality soil samples taken from an additional verticalborehole in the vicinity of the spade cells.(from Authors)
SITE INVESTIGATION AND FIELD OBSERVATION General 962215 Techniques to investigate and remedy sinkholes B. S. Qubain, E. J. Seksinsky & E. G. Aldin, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 341-347. The simple approach involved a visual inspection of the ground surface throughout the building and parking areas. Ground depressions were excavated, revealing substantial
SITE INVESTIGATIONS:REMOTE SENSING voids in the overburden. Once the cavities were exposed and the surrounding soft soils removed, the on-site soils were treated with lime and used as backfill. In contrast, the elaborate approach involved test borings with continuous standard penetration testing. At a third site locations were divided into three classifications depending on the severity of sinkhole activity, and a grouting program was developed to accomplish the needed improvement. At a third site a combination of elaborate and simple techniques was used. Electromagnetic profiling was utilized to delineate potential sinkholes. After excavation of the EM anomalies, geotextiles, rip rap, and lime treated on-site soil were installed to stabilize the sinkhole area. (from Authors)
962216 The use of geochemical methods in the investigation of hazardous waste sites in covered karst terrain T. Glover, J. Daniel & A. Lonergan, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 235-240. A suite of geochemical and statistcal data analysis tools has been used to define local hydrostratigraphy and flow regimes and augment limited drilling, core, and boring data in the interpretation of local areas of recharge, discharge, and interaquifer mixing and a better understanding of the general site characteristics. These tools include water type plots saturation indices, and elemental ratios. (from Authors)
962217 Selection of corridors for power transmission lines and highways through karst terranes E. H. Kastning, in: Karat geohazards: engineering and enviromnental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F~ Beck, (Balkema), 1995, pp 1951198. A major karat area is Currently under simultaneous consideration for routing of a 765-kilovolt power transmission line and several highways, including a major new interstate. For each project, several proposed alternative corridors cross the New River Valley drainage basin, including areas of karst in Montgomery, Craig, Giles, and Bland counties in Virginia and Monroe County in West Virginia. Karst has been mapped in the case of the power lines, albeit the level of detail is wanting. Karat has not been seriously considered during site evaluation for the proposed highways. Power-line and highway corridors coincide in some areas and not in others. Composite maps compiled by citizens action groups and this author indicate potentially threatening environmental problems in the region. (from Authors)
962218 Paleokarstic features in the Belgian carboniferous timestones - implications to engineering A. V. Y. Quinif & J. M. Charlet, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, B.F. Beck, (Balkema), 1995, pp 487-486. Proposes an efficient and comprehensive procedure locating Palaeokarst, defines a method of prospection appropriate to the type of karsts detected and describes an experiment applied to the 'Carriere du Milieu' terrain situated in the Tournaisis area. Both radon and temperature measurements were taken and interpreted by also taking into account a preliminary study of the morphostructures of the site. (from Authors)
75A
Remote sensing and photographic techniques 962219 Ground gamma radiation maps: processing of airborne, laboratory, and/n situ spectrometry data L. Rybach & G. F. Schwarz, First Break, 13(3), 1995, pp 97104. Maps of terrestrial gamma radiation, when converted to dose rate distribution, are indispensable for various purposes: they provide basic information for radiation biology and a welldocumented reference base for accident and emergency situations. Furthermore, they can aid geological mapping and/or prospecting for raw materials. Gamma radiation maps are especially needed on the scale of whole countries. Here, the methodology followed to establish a set of ground gamma radiation maps for Switzerland is summarized. (from Authors) 962220 Statistical interpretation of airborne gamma-ray spectrometric data, Esh E1 Milaha area, northern East Desert, Egypt S. I. Ruble, M. E. Mostafa & A. F. Khalil, Journal of African Earth Sciences, 19(1-2), 1994, pp 117-123. The technique of factor analysis has been applied to airborne gamma-ray spectrometric data. This analysis allows the geophysicists to perform a co-ordinated transformation of the three radioactive element concentrations (eU, eTh and K%), their ratios and the total count. The calculated factor scores may be used to spatially characterize different rock units in the area. (from Authors) 962221 Thermal emission from particulate surfaces: a comparison of scattering models with measured spectra J. E. Moersch & P. R. Christensen, Journal of Geophysical Research, 100(E4), 1995, pp 7465-7477. Emissivity spectra of particulate mineral samples are highly dependent on particle size when that size is comparable to the wavelength of light emitted (5-50 Inn for the midinfrared). Proper geologic interpretation of data from planetary infrared spectrometers will require that these particle size effects be well understood. To address this issue, samples of quartz powders were produced with narrow, well-characterized particle size distributions. Mean particle diameters in these samples ranged from 15 to 277 pro. Emission spectra of these powders allow the first detailed comparison of the complex spectral variations with particle size observed in laboratory data with the predictions of radiative transfer models. Four such models are considered. (from Authors) 962222 Remote sensing provides high-tech clues for mineral exploration C. H. Spencer, Earth Observation Magazine, 4(1), 1995, pp 21-23. This article provides an overview of how the high technology of satellite imagery can be used in the identification and location of minerals. A background on the instrumentation, in the form of a description of the major platforms and sensors available is given. This includes Landsat MSS and TM, SPOT and SAR. The relative advantages of using satellite imagery is covered with also an assessment of each sensor capability and the applications of mineral identication, exploration geology and geobotany. (after Author)
962223 Geotechnologies facilitate geologic mapping and field operations in Colombia J. M. Ellis, W. Narr, P. B. Goodwin & G. Perez, Earth Observation Magazine, 4(2), 1995, pp 18-21. This article provides an investigation into the use of Landsat TM, SPOT, SAR imagery and aerial photography as sources