DC Sego | University of Alberta (original) (raw)
Papers by DC Sego
International Journal of Rock Mechanics and Mining Sciences, 2007
... These features are also illustrated in Fig. 5 and in this sense, the PB model is a more reali... more ... These features are also illustrated in Fig. 5 and in this sense, the PB model is a more realistic bond model for rock-like materials whereby the bonds may break in either tension or shearing with an associated reduction in stiffness. ... 2.4.3. Effect of particle size. ...
Journal of Cold Regions Engineering, 1996
ABSTRACT
Journal of Cold Regions Engineering, 2003
ABSTRACT
Canadian Geotechnical Journal, 2000
One of the primary objectives of the Canadian Liquefaction Experiment (CANLEX) project was to dev... more One of the primary objectives of the Canadian Liquefaction Experiment (CANLEX) project was to develop and evaluate undisturbed sampling techniques as part of the overall goal to focus and coordinate Canadian geotechnical expertise on the topic of soil liquefaction. Six sites were selected by the CANLEX project in an attempt to characterize various deposits of loose sandy soil. The sites consisted of a variety of soil deposits, including hydraulically placed sand deposits associated with the oil sands industry, natural sand deposits in the Fraser River Delta, and hydraulically placed sand deposits associated with the hard-rock mining industry. At each site, a target zone was selected and various methods of ground sampling were performed. These included ground freezing and sampling, fixed piston tube sampling, Christensen double-tube core sampling, large-diameter sampling using the Laval sampler, and sonic (rotary-vibratory) continuous coring. Ground freezing and sampling was performe...
A geogrid reinforced cohesive soil test embankment 12 metres high with 1:1 side slopes is under c... more A geogrid reinforced cohesive soil test embankment 12 metres high with 1:1 side slopes is under construction in the province of Alberta. Three different types of geogrids are being evaluated at the site, including tensar SR2, signode tnx-5001, and paragrid 50s. This paper outlines the geometric layout for the test fill and the design methods currently used for this type of reinforced slope. Instrumentation has been installed to monitor pore pressure responses and the deformations of both the in situ foundation soils and the compacted fill material. Through the analysis of the soil-geogrid interaction performance, a rational design approach will be developed for high geogrid reinforced slopes constructed with cohesive soils. For the covering abstract of the conference see IRRD 807201.
Geotechnical Testing Journal, 2021
Journal American Society of Mining and Reclamation, 1998
Rock Mechanics and Rock Engineering, 2009
Several mix &signs of a Ciment Fondu based grout were tested in the laboratory to develop a grout... more Several mix &signs of a Ciment Fondu based grout were tested in the laboratory to develop a grout which would perform adequately as a pile back611 material in permafrost as wld as -lO°C. The test procedure and results of thermal, compressive strength. and workability performance of the different mix designs are described in &tail. Resume Plusieurs m6langes de codis B base de ccciment Fondu* ont 6t6s exp6riment6s en laboratoire afrn de dbvelopper un coulis pouvant se wmporter de fapn adequate comme mat6riel de remplissage pour des pieux implant6s dam le perg6lisol jusqu'B -lO°C. L'exp6rimentation ainsi que les rbsultats en terme & performance thermique. de rbsistance en compression et de maniabilit6 pour les diffbrent m6langes sont
Journal of Hydraulic Research, 2003
This paper presents the results of a laboratory study undertaken to examine the effect of hydraul... more This paper presents the results of a laboratory study undertaken to examine the effect of hydraulic variables on the scour of a cohesive soil produced by submerged plane turbulent wall jets. The velocity and thickness of the jet were varied in tests with one cohesive soil in part to determine if repeatable scour experiments by these jets could be performed
Journal of Cold Regions Engineering, 2000
Spray freezing technology has been used in ice building construction in cold regions and artifici... more Spray freezing technology has been used in ice building construction in cold regions and artificial snow making. The spray freezing process involves heat and mass transfer and ice nucleation. The freezing temperature of the sprayed water is influenced by many factors, such as droplet size (volume), ambient air temperature, and impurity content of the water. An experimental study was carried out to investigate the influence of the droplet size (volume) and the ambient air temperature on the ice nucleation temperature of the freely suspended droplets of different qualities—piggery wastewater, pulp mill effluent, and oil sands tailings pond water. The time required to initiate freezing in the freely suspended wastewater droplets was measured under various experimental conditions using video-image technology. The ice nucleation temperature of the droplets were predicted based on the required freezing time and the rate of heat and mass transfer.
Journal of Cold Regions Engineering, 2004
This study was carried out to investigate organic and inorganic contaminant removal from melting ... more This study was carried out to investigate organic and inorganic contaminant removal from melting spray ice produced from aerated stabilization basin treated pulp mill wastewater and the oil sands tailings pond water. The influence of the feedwater characteristics and the ice column contaminant concentration and distribution patterns induced by the degree of freezing during the spraying on the release of impurities were examined. The contaminant separation efficiency was not significantly influenced by the characteristics of the wastewaters. A dramatic decrease of chemical oxygen demand, total organic carbon, conductivity, color (pulp mill effluent), and Cl\u-. and SO-\(2/4) (oil sands tailings pond water) concentration in the early meltwater occurred in all ice columns produced with drainwater formation during spraying. Most impurities entrapped within the ice columns had moved to the bottom of the columns, therefore a greater volume of high-quality meltwater was produced. Release of impurities from these ice columns was best described using a power equation. Reduction of meltwater impurity concentration was much slower when the impurities were distributed uniformly in the ice columns as occurred when no drainwater was produced during spraying. In this case, the decay of the meltwater impurity concentration was best predicted using an exponential function. Preferential release of one type of contaminant over others occurred under some experimental conditions.
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1991
... Scott, EA Richards & Y.(Bill) Liu University of Alberta, Edmonton, Alb., Canada ABSTRACT:... more ... Scott, EA Richards & Y.(Bill) Liu University of Alberta, Edmonton, Alb., Canada ABSTRACT: A 12 m high geogrid reinforced test embankment constructed of cohesive soil, which contains three reinforced and one un-reinforced test section has been built near Devon, Albcna The ...
International Journal of Mining, Reclamation and Environment, 2007
Large volumes of the tailings produced as a result of mineral and energy production are disposed ... more Large volumes of the tailings produced as a result of mineral and energy production are disposed of on the Earth's surface. A major concern of mining operations is how to minimize the environmental impact and reduce the storage volume of tailings. In addition, pressure to optimally use scarce water resources, especially in arid regions, is critical. Maximum recycle and reuse
Canadian Journal of Civil Engineering, 1993
A grout for use in pile installation in permafrost is described. The high alumina cement (Ciment ... more A grout for use in pile installation in permafrost is described. The high alumina cement (Ciment Fondu) based grout cures by rapidly evolving heat which maintains it above 0 °C until it hydrates and hardens. The laboratory development program of the mix design along with the cement admixtures which allows the grout to cure at temperatures as low as −10 °C and to remain workable during field use is reviewed. The development of installation procedures for the grout during construction of short range radar foundations is described along with field measurements of the compressive strength and the temperature profiles of the grout after placement in permafrost as cold as −14 °C. The Ciment Fondu grout performed according to the design requirement of hardening without freezing in permafrost colder than −10 °C during the installation of about 2000 piles for part of the short range radar project. Key words: permafrost, grout, laboratory, field, installation procedure, mix design.
Canadian Journal of Civil Engineering, 1992
The effect of a temperature gradient on the process of moisture movement within the landfill envi... more The effect of a temperature gradient on the process of moisture movement within the landfill environment has not been studied in cold-climatic regions. A laboratory study investigating the migration and accumulation of moisture within shredded municipal refuse subjected to a temperature gradient is reported. The laboratory study consisted of four series of experiments involving three samples in each series. The measured parameters included water intake rate from a free water source, final moisture content profiles, and temperature gradient. In each series of experiments, water intake to the sample was attributed to the freezing process. The parameter which characterizes the relationships between the measured water intake rate and temperature gradient is the segregation potential. The results of the tests showed that moisture migrates through the freezing refuse to form ice lenses. The significance of this moisture movement during the cold weather is the increase in the leachate prod...
Canadian Geotechnical Journal, 1994
In situ ground freezing to obtain undisturbed samples of a loose sand beneath the Duncan Dam in B... more In situ ground freezing to obtain undisturbed samples of a loose sand beneath the Duncan Dam in British Columbia is described. This was the first known use of ground freezing to assist in obtaining samples at depth greater than 10 m in Canada. Once frozen, the sand was cored and brought to the surface using a Cold Regions Research and Engineering Laboratory core barrel, which is used extensively in permafrost regions. The design, installation, and performance of the liquid nitrogen freezing systems are described in detail. The drilling, sampling, and preparation of the frozen core for transport to the testing facility are also outlined. The quality of the core retrieved during the sampling was judged to be excellent, and good agreement was found between the void ratios measured using both the frozen core and high-quality gamma–gamma density logging techniques, which were performed adjacent to ground-freezing and sampling locations. Key words : ground freezing, cohesionless soils, un...
Canadian Geotechnical Journal, 1994
A study has been carried out to investigate the influence of fines and gradation on the skeletal ... more A study has been carried out to investigate the influence of fines and gradation on the skeletal collapse behaviour of loosely prepared sand samples. Loose sand samples, formed by moist tamping and consolidated to the same effective stress level, were prepared with varying percentages of both plastic and non-plastic fines (< 74 μm) and non-plastic fine sand (> 74 μm). Samples were isotropically consolidated and subjected to monotonic undrained triaxial compression. Results indicate that increased percentages of fines (< 74 μm) have a pronounced effect on the monotonic undrained behaviour at large strains (> 0.5%). This change is represented by a decreased strain softening behaviour and a shifting of the steady-state line. Variation of the gradation of the host sand appears to have little effect on the monotonic undrained behaviour. A supplemental study, involving use of the scanning electron microscope, was carried out to evaluate the findings of the test program in term...
Canadian Geotechnical Journal, 1993
Loose cohesionless materials can collapse during either static or dynamic loading, resulting in a... more Loose cohesionless materials can collapse during either static or dynamic loading, resulting in a rapid buildup of pore pressure and associated reduction in shear resistance. As the cohesionless material collapses, it rapidly looses resistance until the acting shear stress decreases to the available residual or steady-state strength. Specially designed stress-path testing has been performed on sand to investigate this collapse process. Results from this test program and previously published data show that a state boundary can be defined when a cohesionless material moves from peak to steady state along a constant void ratio stress path regardless of whether it is loaded drained or undrained. Further, it is demonstrated that the state boundary represents a surface in the effective mean normal stress–deviator stress–void ratio space. Hence, flow slides and liquefaction can be initiated when the stress path followed during either drained or undrained loading attempts to cross this stat...
Canadian Geotechnical Journal, 1989
This note presents the results of a limited number of laboratory-scale pile load tests to establi... more This note presents the results of a limited number of laboratory-scale pile load tests to establish those modifications to current pile construction procedures that would be most effective in increasing pile capacity. The results indicate that the properties of the backfill (ice content, salinity, and size of annulus) have a significant influence on short-term pile capacity, while the properties of the native soil are less important. The results demonstrate that the pile capacity can be maximized through the use of nonsaline sand backfill. In saline soils, the shear strength at the backfill - native soil interface may govern the design, and must be evaluated together with the adfreeze strength at the pile-backfill interface. The results also demonstrate that the roughness of the outside surface of the pile has a significant influence on adfreeze strength. Sandblasting the pile surface doubled the adfreeze strength at the pipe-backfill interface. This effect appears to be due to incr...
International Journal of Rock Mechanics and Mining Sciences, 2007
... These features are also illustrated in Fig. 5 and in this sense, the PB model is a more reali... more ... These features are also illustrated in Fig. 5 and in this sense, the PB model is a more realistic bond model for rock-like materials whereby the bonds may break in either tension or shearing with an associated reduction in stiffness. ... 2.4.3. Effect of particle size. ...
Journal of Cold Regions Engineering, 1996
ABSTRACT
Journal of Cold Regions Engineering, 2003
ABSTRACT
Canadian Geotechnical Journal, 2000
One of the primary objectives of the Canadian Liquefaction Experiment (CANLEX) project was to dev... more One of the primary objectives of the Canadian Liquefaction Experiment (CANLEX) project was to develop and evaluate undisturbed sampling techniques as part of the overall goal to focus and coordinate Canadian geotechnical expertise on the topic of soil liquefaction. Six sites were selected by the CANLEX project in an attempt to characterize various deposits of loose sandy soil. The sites consisted of a variety of soil deposits, including hydraulically placed sand deposits associated with the oil sands industry, natural sand deposits in the Fraser River Delta, and hydraulically placed sand deposits associated with the hard-rock mining industry. At each site, a target zone was selected and various methods of ground sampling were performed. These included ground freezing and sampling, fixed piston tube sampling, Christensen double-tube core sampling, large-diameter sampling using the Laval sampler, and sonic (rotary-vibratory) continuous coring. Ground freezing and sampling was performe...
A geogrid reinforced cohesive soil test embankment 12 metres high with 1:1 side slopes is under c... more A geogrid reinforced cohesive soil test embankment 12 metres high with 1:1 side slopes is under construction in the province of Alberta. Three different types of geogrids are being evaluated at the site, including tensar SR2, signode tnx-5001, and paragrid 50s. This paper outlines the geometric layout for the test fill and the design methods currently used for this type of reinforced slope. Instrumentation has been installed to monitor pore pressure responses and the deformations of both the in situ foundation soils and the compacted fill material. Through the analysis of the soil-geogrid interaction performance, a rational design approach will be developed for high geogrid reinforced slopes constructed with cohesive soils. For the covering abstract of the conference see IRRD 807201.
Geotechnical Testing Journal, 2021
Journal American Society of Mining and Reclamation, 1998
Rock Mechanics and Rock Engineering, 2009
Several mix &signs of a Ciment Fondu based grout were tested in the laboratory to develop a grout... more Several mix &signs of a Ciment Fondu based grout were tested in the laboratory to develop a grout which would perform adequately as a pile back611 material in permafrost as wld as -lO°C. The test procedure and results of thermal, compressive strength. and workability performance of the different mix designs are described in &tail. Resume Plusieurs m6langes de codis B base de ccciment Fondu* ont 6t6s exp6riment6s en laboratoire afrn de dbvelopper un coulis pouvant se wmporter de fapn adequate comme mat6riel de remplissage pour des pieux implant6s dam le perg6lisol jusqu'B -lO°C. L'exp6rimentation ainsi que les rbsultats en terme & performance thermique. de rbsistance en compression et de maniabilit6 pour les diffbrent m6langes sont
Journal of Hydraulic Research, 2003
This paper presents the results of a laboratory study undertaken to examine the effect of hydraul... more This paper presents the results of a laboratory study undertaken to examine the effect of hydraulic variables on the scour of a cohesive soil produced by submerged plane turbulent wall jets. The velocity and thickness of the jet were varied in tests with one cohesive soil in part to determine if repeatable scour experiments by these jets could be performed
Journal of Cold Regions Engineering, 2000
Spray freezing technology has been used in ice building construction in cold regions and artifici... more Spray freezing technology has been used in ice building construction in cold regions and artificial snow making. The spray freezing process involves heat and mass transfer and ice nucleation. The freezing temperature of the sprayed water is influenced by many factors, such as droplet size (volume), ambient air temperature, and impurity content of the water. An experimental study was carried out to investigate the influence of the droplet size (volume) and the ambient air temperature on the ice nucleation temperature of the freely suspended droplets of different qualities—piggery wastewater, pulp mill effluent, and oil sands tailings pond water. The time required to initiate freezing in the freely suspended wastewater droplets was measured under various experimental conditions using video-image technology. The ice nucleation temperature of the droplets were predicted based on the required freezing time and the rate of heat and mass transfer.
Journal of Cold Regions Engineering, 2004
This study was carried out to investigate organic and inorganic contaminant removal from melting ... more This study was carried out to investigate organic and inorganic contaminant removal from melting spray ice produced from aerated stabilization basin treated pulp mill wastewater and the oil sands tailings pond water. The influence of the feedwater characteristics and the ice column contaminant concentration and distribution patterns induced by the degree of freezing during the spraying on the release of impurities were examined. The contaminant separation efficiency was not significantly influenced by the characteristics of the wastewaters. A dramatic decrease of chemical oxygen demand, total organic carbon, conductivity, color (pulp mill effluent), and Cl\u-. and SO-\(2/4) (oil sands tailings pond water) concentration in the early meltwater occurred in all ice columns produced with drainwater formation during spraying. Most impurities entrapped within the ice columns had moved to the bottom of the columns, therefore a greater volume of high-quality meltwater was produced. Release of impurities from these ice columns was best described using a power equation. Reduction of meltwater impurity concentration was much slower when the impurities were distributed uniformly in the ice columns as occurred when no drainwater was produced during spraying. In this case, the decay of the meltwater impurity concentration was best predicted using an exponential function. Preferential release of one type of contaminant over others occurred under some experimental conditions.
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1991
... Scott, EA Richards & Y.(Bill) Liu University of Alberta, Edmonton, Alb., Canada ABSTRACT:... more ... Scott, EA Richards & Y.(Bill) Liu University of Alberta, Edmonton, Alb., Canada ABSTRACT: A 12 m high geogrid reinforced test embankment constructed of cohesive soil, which contains three reinforced and one un-reinforced test section has been built near Devon, Albcna The ...
International Journal of Mining, Reclamation and Environment, 2007
Large volumes of the tailings produced as a result of mineral and energy production are disposed ... more Large volumes of the tailings produced as a result of mineral and energy production are disposed of on the Earth's surface. A major concern of mining operations is how to minimize the environmental impact and reduce the storage volume of tailings. In addition, pressure to optimally use scarce water resources, especially in arid regions, is critical. Maximum recycle and reuse
Canadian Journal of Civil Engineering, 1993
A grout for use in pile installation in permafrost is described. The high alumina cement (Ciment ... more A grout for use in pile installation in permafrost is described. The high alumina cement (Ciment Fondu) based grout cures by rapidly evolving heat which maintains it above 0 °C until it hydrates and hardens. The laboratory development program of the mix design along with the cement admixtures which allows the grout to cure at temperatures as low as −10 °C and to remain workable during field use is reviewed. The development of installation procedures for the grout during construction of short range radar foundations is described along with field measurements of the compressive strength and the temperature profiles of the grout after placement in permafrost as cold as −14 °C. The Ciment Fondu grout performed according to the design requirement of hardening without freezing in permafrost colder than −10 °C during the installation of about 2000 piles for part of the short range radar project. Key words: permafrost, grout, laboratory, field, installation procedure, mix design.
Canadian Journal of Civil Engineering, 1992
The effect of a temperature gradient on the process of moisture movement within the landfill envi... more The effect of a temperature gradient on the process of moisture movement within the landfill environment has not been studied in cold-climatic regions. A laboratory study investigating the migration and accumulation of moisture within shredded municipal refuse subjected to a temperature gradient is reported. The laboratory study consisted of four series of experiments involving three samples in each series. The measured parameters included water intake rate from a free water source, final moisture content profiles, and temperature gradient. In each series of experiments, water intake to the sample was attributed to the freezing process. The parameter which characterizes the relationships between the measured water intake rate and temperature gradient is the segregation potential. The results of the tests showed that moisture migrates through the freezing refuse to form ice lenses. The significance of this moisture movement during the cold weather is the increase in the leachate prod...
Canadian Geotechnical Journal, 1994
In situ ground freezing to obtain undisturbed samples of a loose sand beneath the Duncan Dam in B... more In situ ground freezing to obtain undisturbed samples of a loose sand beneath the Duncan Dam in British Columbia is described. This was the first known use of ground freezing to assist in obtaining samples at depth greater than 10 m in Canada. Once frozen, the sand was cored and brought to the surface using a Cold Regions Research and Engineering Laboratory core barrel, which is used extensively in permafrost regions. The design, installation, and performance of the liquid nitrogen freezing systems are described in detail. The drilling, sampling, and preparation of the frozen core for transport to the testing facility are also outlined. The quality of the core retrieved during the sampling was judged to be excellent, and good agreement was found between the void ratios measured using both the frozen core and high-quality gamma–gamma density logging techniques, which were performed adjacent to ground-freezing and sampling locations. Key words : ground freezing, cohesionless soils, un...
Canadian Geotechnical Journal, 1994
A study has been carried out to investigate the influence of fines and gradation on the skeletal ... more A study has been carried out to investigate the influence of fines and gradation on the skeletal collapse behaviour of loosely prepared sand samples. Loose sand samples, formed by moist tamping and consolidated to the same effective stress level, were prepared with varying percentages of both plastic and non-plastic fines (< 74 μm) and non-plastic fine sand (> 74 μm). Samples were isotropically consolidated and subjected to monotonic undrained triaxial compression. Results indicate that increased percentages of fines (< 74 μm) have a pronounced effect on the monotonic undrained behaviour at large strains (> 0.5%). This change is represented by a decreased strain softening behaviour and a shifting of the steady-state line. Variation of the gradation of the host sand appears to have little effect on the monotonic undrained behaviour. A supplemental study, involving use of the scanning electron microscope, was carried out to evaluate the findings of the test program in term...
Canadian Geotechnical Journal, 1993
Loose cohesionless materials can collapse during either static or dynamic loading, resulting in a... more Loose cohesionless materials can collapse during either static or dynamic loading, resulting in a rapid buildup of pore pressure and associated reduction in shear resistance. As the cohesionless material collapses, it rapidly looses resistance until the acting shear stress decreases to the available residual or steady-state strength. Specially designed stress-path testing has been performed on sand to investigate this collapse process. Results from this test program and previously published data show that a state boundary can be defined when a cohesionless material moves from peak to steady state along a constant void ratio stress path regardless of whether it is loaded drained or undrained. Further, it is demonstrated that the state boundary represents a surface in the effective mean normal stress–deviator stress–void ratio space. Hence, flow slides and liquefaction can be initiated when the stress path followed during either drained or undrained loading attempts to cross this stat...
Canadian Geotechnical Journal, 1989
This note presents the results of a limited number of laboratory-scale pile load tests to establi... more This note presents the results of a limited number of laboratory-scale pile load tests to establish those modifications to current pile construction procedures that would be most effective in increasing pile capacity. The results indicate that the properties of the backfill (ice content, salinity, and size of annulus) have a significant influence on short-term pile capacity, while the properties of the native soil are less important. The results demonstrate that the pile capacity can be maximized through the use of nonsaline sand backfill. In saline soils, the shear strength at the backfill - native soil interface may govern the design, and must be evaluated together with the adfreeze strength at the pile-backfill interface. The results also demonstrate that the roughness of the outside surface of the pile has a significant influence on adfreeze strength. Sandblasting the pile surface doubled the adfreeze strength at the pipe-backfill interface. This effect appears to be due to incr...