Showing papers in "Canadian Geotechnical Journal in 1991"
TL;DR: The existing segregation potential (SP) method for frost heave prediction in soils is semi-empirical in nature and does not explicitly predict the relationship between heave rate, temperature gradients.
Abstract: The existing segregation potential (SP) method for frost heave prediction in soils is semiempirical in nature and does not explicitly predict the relationship between heave rate, temperature gradie...
201 citations
TL;DR: In this article, a field test was undertaken to assess the effectiveness of electroosmosis in strengthening the soft sensitive (Leda) clay at the Gloucester test fill site.
Abstract: A field test was undertaken to assess the effectiveness of electroosmosis in strengthening the soft sensitive (Leda) clay at the Gloucester test fill site. Specially designed copper electrodes were...
127 citations
TL;DR: In this paper, a comprehensive experimental investigation on the electroosmotic strengthening of soft sensitive clay was performed to assess the effectiveness of the treatment and to study the mechanism of the pr...
Abstract: A comprehensive experimental investigation on the electroosmotic strengthening of soft sensitive clay was performed to assess the effectiveness of the treatment and to study the mechanism of the pr...
104 citations
TL;DR: In this paper, the impact of closed-system freeze-thaw cycles on the permeability of clay, till, and sand-bentonite mixtures was examined in a laboratory test program.
Abstract: The impact of closed-system freeze–thaw cycles on the permeability of clay, till, and sand–bentonite mixtures was examined in a laboratory test program. The bentonite content of the sand–bentonite mixtures varied from 4.5 to 25%. Test samples were prepared by dry mixing, moisture conditioning, and compacting materials according to ASTM D698, method A specifications. The molding water content of these samples was at or slightly wet of optimum. Trimmed test samples were placed in a triaxial permeameter and their unfrozen or initial permeability was established. These permeability tests were conducted for approximately 10 000 min using low hydraulic gradients and confining stress. Changes in specimen volume were also measured during permeability testing. Once the initial permeability of a specimen was established, the test was halted and the specimen was frozen inside the permeameter with no access to water. After freezing, the specimens were allowed to thaw before a second permeability test was conducted. T...
90 citations
TL;DR: In this paper, a 3D elastoplastic finite-element analysis is proposed to simulate the advance of a tunnelling shield and the associated ground losses resulting from the tunneling procedure.
Abstract: A three-dimensional (3D) elastoplastic finite-element analysis, which is capable of simulating the advance of a tunnelling shield and the associated ground losses resulting from the tunnelling proc...
86 citations
TL;DR: In this article, a detailed laboratory investigation was conducted on Mae Moh fly ash from northern Thailand for the determination of its grain size distribution, mineralogy, pozzolanic activity, compaction and str...
Abstract: Detailed laboratory investigations were conducted on Mae Moh fly ash from northern Thailand for the determination of its grain size distribution, mineralogy, pozzolanic activity, compaction and str...
83 citations
77 citations
TL;DR: In this paper, the mechanical behavior of Champlain Sea clays when subjected to one cycle of freeze-thaw was investigated and it appears that most of the characteristics, namely, the undrained shear strength, th...
Abstract: This paper presents the mechanical behaviour of Champlain Sea clays when subjected to one cycle of freeze-thaw. It appears that most of the characteristics, namely, the undrained shear strength, th...
71 citations
TL;DR: In this article, the results of a research study on a natural clay from southwestern Ontario permeated with various mixtures of landfill leachate and water-soluble organic liquids at effective stresses ranging from 0 to ~300 kPa were presented.
Abstract: The magnitude of the effective stresses acting on a clay barrier appear to play a critical role in preserving low hydraulic conductivity, k, during exposure to soluble organic liquids. This paper summarizes the results of a research study on a natural clay from southwestern Ontario permeated with various mixtures of landfill leachate and water-soluble organic liquids at effective stresses ranging from 0 to ~300 kPa. Laboratory testing of "unconfined", water-compacted clays indicated that municipal solid waste leachates containing ethanol and dioxane at concentrations in excess of 70% can cause damaging increases in k of up to 1000-fold. Predamage application of vertical effective stresses can reduce or even eliminate these increases in k because of chemically induced consolidation and closure of macropores that develop as a result of double layer collapse. The levels of static effective stress required to prevent the increases in k were much higher for nonpolar dioxane (> 160 kPa) than for intermediately ...
69 citations
TL;DR: In this paper, the collapse behavior of a compacted, uncemented soil is studied within a theoretical context consistent with the concepts of unsaturated soil mechanics, and experimental data are presented relating th...
Abstract: The collapse behavior of a compacted, uncemented soil is studied within a theoretical context consistent with the concepts of unsaturated soil mechanics. Experimental data are presented relating th...
TL;DR: In this paper, experimental and theoretical studies on the torque required to install screw anchors in sand are presented, and tests are conducted on five models of screw anchors with different geometry to study the performance.
Abstract: Experimental and theoretical studies on the torque required to install screw anchors in sand are presented. Tests were conducted on five models of screw anchors with different geometry to study the...
TL;DR: In this paper, a numerical model was used to investigate the importance of moisture-retention characteristics in the transient drainage of two-layer systems and the results showed that the effectiveness of a material as a moisture-regaining cover is dependent on the magnitude of its air-entry value.
Abstract: Acid generation in reactive mine tailings is an oxidation process that is dependent on availability of molecular oxygen. As a consequence of the diffusion coefficient of oxygen being several orders of magnitude higher in air than in water, influx of atmospheric oxygen into a material at depth can theoretically be minimized by maintaining a protective cover layer at high moisture content. Such oxygen-limiting covers are generally of finer texture than the material being protected. A numerical model was used to investigate the importance of moisture-retention characteristics in the transient drainage of such two-layer systems. The results show that the effectiveness of a material as a moisture-retaining cover is dependent on the magnitude of its air-entry value. The thickness of the cover maintained at full saturation after prolonged drainage also depends on the pressure head at which the underlying material approaches residual saturation. Key words: geologic covers, tailings, numerical simulations, air-ent...
TL;DR: In this paper, a tunnel excavated by a tunnel boring machine was monitored extensively by means of extensometers installed near the tunnel face, and the three-dimensional state existing at the time of excavation was reconstructed.
Abstract: A tunnel excavated by a tunnel boring machine was monitored extensively by means of extensometers installed near the tunnel face. Consequently, the three-dimensional state existing at the time of i...
TL;DR: Permeability measurements using a consolidometer were made for kaolinite, montmorillonite, and a clay-rich soil (the Lockport clay) with a variety of organic liquids and water as permeants as discussed by the authors.
Abstract: Permeability measurements, using a consolidometer, were made for kaolinite, montmorillonite, and a clay-rich soil (the Lockport clay) with a variety of organic liquids and water as permeants. These...
TL;DR: A field test was undertaken to assess the effectiveness of the electroosmotic strengthening of the soft sensitive (Champlain Sea) clay in the Gloucester Test Fill site by using specially designed c...
Abstract: A field test was undertaken to assess the effectiveness of the electroosmotic strengthening of the soft sensitive (Champlain Sea) clay in the Gloucester Test Fill site by using specially designed c...
TL;DR: In this paper, the scaling laws for physical modeling are presented, and dimensional analysis is used to identify potential difficulties in application of model test results to prototype situations, indicating that centrifuge modelling may be a viable approach to the evaluation of dissolved contaminant transport in partially saturated soils.
Abstract: Computer solutions to the problem of dissolved contaminant movements in saturated soils are readily available. However, for partially saturated soils, extreme nonlinearity of some variables and difficulties in determining values for other variables make computer solutions predicting the movement of dissolved contaminants highly unreliable. Physical modelling in a geotechnical centrifuge is presented as a viable alternative to numerical modelling. Scaling laws for physical modelling are presented in this paper, and dimensional analysis is used to identify potential difficulties in application of model test results to prototype situations. Preliminary results of experimental work are presented. These results indicate that centrifuge modelling may be a viable approach to the evaluation of dissolved contaminant transport in partially saturated soils. Key words: contaminant transport, centrifuge, unsaturated.
TL;DR: The flat dilatometer (DMT) test was introduced by Marchetti (1980) as a new in situ penetration test for soils as discussed by the authors, and the equipment and test procedures are simple, and the test provides repeatable, nearl...
Abstract: The flat dilatometer (DMT) test was introduced by Marchetti (1980) as a new in situ penetration test for soils. The equipment and test procedures are simple, and the test provides repeatable, nearl...
TL;DR: In this article, the authors investigated the relationship between toppling and large deep-seated landslides along the Beaver Valley, Glacier National Park, British Columbia, Canada, and found that the relationship was not causal.
Abstract: This paper is an inquiry into the suspected relationship between toppling and large deep-seated landslides along the Beaver Valley, Glacier National Park, British Columbia. The study area includes ...
TL;DR: In this paper, the influence of a frozen soil layer on the dynamic response of full-scale concrete piles subjected to strong horizontal excitation was studied, and the field measurements were used to postulate empirical relationships that can be used under practical conditions to estimate the magnitude of soil separation around piles embedded in cohesive soils as a function of the maximum vibration amplitude.
Abstract: The influence of a frozen soil layer on the dynamic response of full-scale concrete piles subjected to strong horizontal excitation was studied. The study undertaken compares the field observations against the theoretical predictions and provides an insight into the role of the yielded zone (boundary zone) in theoretically matching the field observations. The field measurements are used to postulate empirical relationships that can be used under practical conditions to estimate the magnitude of soil separation around piles embedded in cohesive soils as a function of the maximum vibration amplitude. The tests performed indicate that the presence of a frozen soil layer, even at a modest thickness of less than 0.5 m, can significantly influence the dynamic response of piles; the horizontal stiffness of the pile was increased by one order of magnitude, and its resonant frequency was increased by a factor of four compared to the situation with no frozen soil layer. The qualitative and quantitative findings fro...
TL;DR: In this paper, the behavior of single free-head model flexible vertical and batter piles under the general case of eccentric and inclined loads in two-layered soil is investigated and the bearing capacity of the pi...
Abstract: The behaviour of single free-head model flexible vertical and batter piles under the general case of eccentric and inclined loads in two-layered soil is investigated. The bearing capacity of the pi...
TL;DR: The preliminary results of a study using mercury-intrusion porosimetry on freeze-dried samples of clayey soils are presented in this paper, where the amount of secondary consolidation has been varied for several samples of three soil types by holding the consolidation stress steady at 120 kPa for different durations.
Abstract: The preliminary results of a study using mercury-intrusion porosimetry on freeze-dried samples of clayey soils are presented. The amount of secondary consolidation has been varied for several samples of three soil types by holding the consolidation stress steady at 120 kPa for different durations. Examination of the pore size distribution curves reveals that secondary consolidation cannot be due solely to the deformation of micropores. The relative degree of change in total, free and entrapped porosity appears to be related to the proportion of each initially in the sample. Key words: clays, consolidation, compressibility, fabric-structure of soils, secondary compression.
TL;DR: In this paper, the long-term study of the behavior of prestressed grouted rock anchors constitutes an important aspect of the stability of the structure retained by these structural members and the loads supplied by these anchors.
Abstract: The long-term study of the behaviour of prestressed grouted rock anchors constitutes an important aspect of the stability of the structure retained by these structural members. The loads supplied b...
TL;DR: The current practice for the design of large-diameter bored piles in residual soils in Singapore is based on the calculated static capacity of the piles as discussed by the authors, which is insufficient consideration of the load-tran...
Abstract: The current practice for the design of large-diameter bored piles in residual soils in Singapore is based on the calculated static capacity of the piles. Insufficient consideration of the load-tran...
TL;DR: In this paper, a ground-penetrating radar profile is deconvolved using the common prediction-error filter, which assumes a white power spectrum for the reflections, and a filter that assumes a spectrum proportional to spatial frequency.
Abstract: Recent advances in ground-probing radar instrumentation have allowed the collection of large volumes of digital data Such data sets are amenable to modern data-processing techniques both to increase geological resolution and to enhance data presentation The close similarity between ground-radar data and seismic data suggests that processing techniques that have been used in the seismic industry could be applied to radar data As an example, a ground probing radar profile is deconvolved using the common prediction-error filter, which assumes a white power spectrum for the reflections, and a filter that assumes a spectrum proportional to spatial frequency With the prediction-error filter we find three of four buried pipes which are not visible in the undeconvolved section; all four are found with the second filter Key words: ground-penetrating radar, deconvolution, scaling geology, frozen-core dams, permafrost, containment dams, mill waste, Contwoyto Lake
TL;DR: In a simple shear test the axes of stress rotate and, in a conventional apparatus in which the only stresses measured are the normal and shear stresses on horizontal planes, it is not possible to measure the axis of stress rotation.
Abstract: During a simple shear test the axes of stress rotate and, in a conventional apparatus in which the only stresses measured are the normal and shear stresses on horizontal planes, it is not possible ...
TL;DR: The profile of overconsolidation ratio (OCR) of a soil deposit is one of the most dominant factors that influence the engineering behavior of the soil as discussed by the authors, and the profile of OCR can be found in the literature.
Abstract: The stress history as indicated by the profile of overconsolidation ratio (OCR) of a soil deposit is one of the most dominant factors that influence the engineering behaviour of the soil. Its asses...
TL;DR: In this paper, the authors made settlement calculations for an earth embankment resting on soft, compressible Fraser River Delta sediments were made from laboratory consolidation tests and in situ tests using a piezocone and a flat dilatometer.
Abstract: Settlement calculations for an earth embankment resting on soft, compressible Fraser River Delta sediments were made from laboratory consolidation tests and in situ tests using a piezocone and a flat dilatometer. The calculated values were compared with measured settlements. There was rather good agreement among the three methods of calculation, but the actual settlement was about 60% greater than the average calculated value. Calculated rates of settlement are also compared with observed values. Key words: consolidation, settlements, piezocone, dilatometer, in situ tests, constrained modulus, pore-water pressure, settlement rate.