Showing papers in "Canadian Geotechnical Journal in 2009"
TL;DR: The electric cone penetration test (CPT) has been in use for over 40 years and is growing in popularity in North America as discussed by the authors, and some recent updates on the interpretation of some key g...
Abstract: The electric cone penetration test (CPT) has been in use for over 40 years and is growing in popularity in North America. This paper provides some recent updates on the interpretation of some key g...
647 citations
TL;DR: In this article, the results of a comprehensive experimental study of the desiccation of fine-grained soils were presented, which revealed that unconstrained drying exhibits two stages: a domain with large, mostly irrecoverable deformations and degree of saturation close to 100%, followed by another domain with lower defor- mations at a decreasing degree of satura- tion.
Abstract: This paper presents the results of a comprehensive experimental study of the desiccation of fine-grained soils. Air drying of initially saturated soil slabs in controlled conditions is investigated by performing three kinds of tests: free desiccation tests, constrained desiccation tests (prevented shrinkage), and crack pattern tests. Strains, suction, water con- tent, and crack geometry are investigated. Results reveal that unconstrained drying exhibits two stages: a domain with large, mostly irrecoverable deformations and degree of saturation close to 100%, followed by a domain with lower defor- mations at a decreasing degree of saturation. Homogeneous soil macroscopic cracking is possible only in the presence of boundary constraints and (or) moisture gradients, inducing the build-up of tensile stresses. Results also show that, for the initially saturated remoulded soils tested here, in the whole sample and near a crack initiation point, the degree of satura- tion remains very close to 100% until cracking, while cracking onset, the air-entry suction, and the shrinkage limit are close to each other. Cavitation nuclei and the formation of an irregular drying front at cracking initiation are commented upon in light of this observation. Finally, results suggest that the crack pattern geometry is the result of energy redistribu- tion. A quantification of the process is proposed. Resume´ : Cet article presente les resultats d'une etude experimentale complete de la dessiccation de sols fins. Le sechage de sols initialement satures est etudiedans des conditions controlees et atemperature ambiante. Trois types d'essais ont eteeffectues : essais de dessiccation libre, essais de dessiccation avec contraintes (le retrait est empechedans une direc- tion) et essais de plans de fissures. Les deformations, la succion, la teneur en eau et la geometrie des fissures ont eteinves- tiguees. Les resultats demontrent que le sechage sans contrainte presente deux etapes : un domaine durant lequel les deformations sont grandes et irreversibles et le degrede saturation reste pres de 100 %, suivi d'un domaine durant lequel les deformations sont plus faibles et le degrede saturation diminue. Pour un sol homogene, des fissures macroscopiques apparaissent seulement lorsqu'il y a des contraintes aux frontieres et (ou) des gradients d'humidite ´, ce qui induit des contraintes en tension. Les resultats montrent aussi que pour les silts et argiles remanies initialement satures utilises dans cette etude, le degrede saturation reste tres pres de 100 % jusqu'ala fissuration. De plus, la fissuration, l'entree d'air et la limite de retrait sont proches les unes des autres. Suite a ces observations, l'existence de germes de cavitation et la forma- tion d'un front de sechage irregulier lors de l'initiation des fissures sont discutees. Finalement, les resultats suggerent que la geometrie des fissures resulte d'une redistribution de l'energie a travers le corps. Une quantification du processus est proposee. Mots-cles: dessiccation, initiation de fissure, succion, succion a l'entree d'air, geometrie des fissures.
337 citations
TL;DR: In this article, the authors discute du comportement du sol soumis a chargement cyclique, pour la structure and les pentes, and demontre que the resistance au cisaillement cyclique and le mode de defaillance sous chargements cyclique dependent fortement du cheminement des contraintes and de la combinaison des containtes en cis-aillement moyennes et cycliques.
Abstract: Le chargement cyclique est important pour la conception de fondations de structures, autant en mer, sur la cote et sur la terre, et pour la stabilite des pentes. Ceci est illustre a l'aide de plusieurs exemples. Cet article discute du comportement du sol soumis a un chargement cyclique, pour la structure et les pentes, et demontre que la resistance au cisaillement cyclique et le mode de defaillance sous chargement cyclique dependent fortement du cheminement des contraintes et de la combinaison des contraintes en cisaillement moyennes et cycliques. Des diagrammes de resistance au cisaillement cyclique pour l'argile, sable et silt, qui peuvent etre utilises pour la conception, sont presentes. Des comparaisons entre les calculs et les essais modelises indiquent que la capacite de la fondation soumise a un chargement cyclique peut etre determinee a partir de la resistance au cisaillement cyclique obtenu par des essais en laboratoire.
201 citations
TL;DR: The microporosity structure of soil provides important information in understanding the shear strength, compressibility, water-retention ability, and hydraulic conductivity of soils as mentioned in this paper.
Abstract: The microporosity structure of soil provides important information in understanding the shear strength, compressibility, water-retention ability, and hydraulic conductivity of soils. It is a soil c...
196 citations
TL;DR: In this article, the role of particle rearrangement through interparticle slip and rotation and particle damage on primary compression on over 100 sands was examined to clarify the role that particle rearrangeement through particle rotation and slip/rotation was played in particle damage.
Abstract: Compression data on over 100 sands were examined to clarify the role of particle rearrangement through interparticle slip and rotation and particle damage on primary compression, including the yiel...
186 citations
TL;DR: In this article, the authors used piezoceramic elements (bender elements) to measure shear wave velocity in soil and rock specimens, and showed that they can be used for laboratory measurement of wave velocity.
Abstract: Piezoceramic elements have been used for laboratory measurement of wave velocity in soil and rock specimens. Shear-wave piezoceramic elements (bender elements) are commonly used to measure shear wa...
107 citations
TL;DR: The very small strain shear modulus of soil, G0, is affected by many factors including soil properties, current stress state, stress history, and matric suction.
Abstract: The very small strain shear modulus of soil, G0, is affected by many factors including soil properties, current stress state, stress history, and matric suction. Very little research has been condu...
106 citations
TL;DR: Bentonite is currently designated for use as a buffer material for the repository of high-level radioactive waste because such a material requires swelling characteristics to seal the waste as discussed by the authors, which is not suitable for high level radioactive waste.
Abstract: Bentonite is currently designated for use as a buffer material for the repository of high-level radioactive waste because such a material requires swelling characteristics to seal the waste. A high...
106 citations
TL;DR: Cracks are prevalent in near-ground-surface soils and provide preferential pathways for fluid flow as discussed by the authors, and they increase water infiltration or contaminant solute transport into soils, which can increase water solute transfer into soils.
Abstract: Cracks are prevalent in near-ground-surface soils and provide preferential pathways for fluid flow. Cracks increase water infiltration or contaminant solute transport into soils. This paper studies...
105 citations
TL;DR: In this paper, the results of a comprehensive pile load test program and observations from field monitoring of helical piles with either a single helix or double helixes installed in oil sand are presented.
Abstract: The results of a comprehensive pile load-test program and observations from field monitoring of helical piles with either a single helix or double helixes installed in oil sand are presented in this paper. Eleven full-scale pile load tests were carried out including axial compression, uplift, and lateral load tests. The results of the full-scale load tests are used to develop a theoretical design model for helical piles installed in oil sand. Test results confirm that the helical pile is a viable deep foundation option for support of heavily loaded structures. The test results also demonstrated that circular-shaft helical piles can resist considerable lateral loads.
105 citations
TL;DR: In this paper, an experimental study was carried out to investigate the static liquefaction behavior of sand with a small amount of plastic and non-plastic fines, and five series of tests were conducted in drained an...
Abstract: An experimental study was carried out to investigate the static liquefaction behaviour of sand with a small amount of plastic and nonplastic fines. Five series of tests were conducted in drained an...
TL;DR: In this paper, the authors combine different types of soil to create a layered cover with capilla, which can be used to control water infiltration into waste disposal sites. But, the cover system is not suitable for outdoor applications.
Abstract: Various types of cover systems can be used to control water infiltration into waste disposal sites. One promising option is to combine different types of soil to create a layered cover with capilla...
TL;DR: In this article, the unsaturated soil interface is defined as a lay-through point where unsaturated soils are in contact with structures such as foundations, retaining walls, and buried pipes.
Abstract: Unsaturated soil interfaces exist where unsaturated soil is in contact with structures such as foundations, retaining walls, and buried pipes. The unsaturated soil interface can be defined as a lay...
TL;DR: In this article, a semi-empirical model is proposed to predict the variation of modulus of elasticity with respect to matric suction for unsaturated sandy soils using the soil-water characteristic cur...
Abstract: A semi-empirical model is proposed in this paper to predict the variation of modulus of elasticity with respect to matric suction for unsaturated sandy soils using the soil-water characteristic cur...
TL;DR: Unsaturated hydraulic conductivity is the primary soil parameter required when performing seepage analyses for unsaturated-saturated soil systems as discussed by the authors. But it is not a suitable soil parameter for seeping.
Abstract: Unsaturated hydraulic conductivity is the primary soil parameter required when performing seepage analyses for unsaturated–saturated soil systems. Unsaturated hydraulic conductivity is also one of ...
TL;DR: In this article, the long-term performance of lime-treated soil is still in question, especially in the case of the use of such soils to build earthen structures in permanent contact with water (i.e., dams, river levees, etc.).
Abstract: The long-term performance of lime-treated soil is still in question, especially in the case of the use of such soils to build earthen structures in permanent contact with water (i.e., dams, river levees, etc.) Indeed, water circulation may induce significant alteration of the improvements brought by the lime treatment. In this context, the main objective of this work is to study the long-term behaviour (durability) of lime-treated soils submitted to water circulation as well as to determine the most favourable initial soil compaction in terms of lime-treated soil durability. First, the impact of lime addition on soil microstructure is investigated with mercury intrusion porosimetry tests. This was done to highlight the effect of curing time, lime dosage, and compaction on soil initial permeability, a critical parameter in terms of long-term behaviour of the lime-treated soil. Then, lime-treated soil samples were submitted to an accelerated circulation of water over a period of 150 days. The obtained resul...
TL;DR: In this article, the results of an extensive parametric study on single piles and pile groups embedded in a two-layer subsoil profile were presented, and the authors aimed to evaluate kinematic bending moments developi...
Abstract: This paper presents the results of an extensive parametric study on single piles and pile groups embedded in a two-layer subsoil profile, and is aimed to evaluate kinematic bending moments developi...
TL;DR: In underground mining using open stoping, it is common to backfill mined-out voids (stopes) using hydraulically placed backfill, which is commonly composed of tailings.
Abstract: In current underground mining using “open stoping” methods, it is common to backfill mined-out voids (“stopes”) using hydraulically placed backfill, which is commonly composed of tailings, to which...
TL;DR: In this article, the authors deal with development of artificial neural networks (ANNs) and multiple regression analysis (MRA) models for determining hydraulic conductivity of fine-grained soils.
Abstract: This study deals with development of artificial neural networks (ANNs) and multiple regression analysis (MRA) models for determining hydraulic conductivity of fine-grained soils. To achieve this, c...
TL;DR: In this article, a new method of using large-diameter, cast-in-in situ concrete pipe (PCC) piles for embankments over soft clay is introduced.
Abstract: A new method of using large-diameter, cast–in situ concrete pipe (PCC) piles for embankments over soft clay is introduced in this paper. This PCC pile method offers a relatively quick and cost-effe...
TL;DR: In this paper, the results of four centrifuge model tests were undertaken to investigate behavior of floating piles subjected to negative skin friction (NSF) and to study effects of axial...
Abstract: This paper reports the results of four centrifuge model tests that were undertaken to investigate behavior of floating piles subjected to negative skin friction (NSF) and to study effects of axial ...
TL;DR: In this article, three large 10 m high standpipe tests were set up at the University of Alberta in 1982 to simulate large-scale compression behavior of oil sands tailings in a controlled environment.
Abstract: Three large 10 m high standpipe tests were set up at the University of Alberta in 1982 to simulate large-scale compression behavior of oil sands tailings in a controlled environment. The objectives...
TL;DR: Soil structures are often comprised or supported by soils that are mixtures of cohesive and granular geomaterials, termed as intermediate or mixed soils and are widely found in nature.
Abstract: Soil structures are often comprised or supported by soils that are mixtures of cohesive and granular geomaterials. These soils are termed as intermediate or mixed soils and are widely found in natu...
TL;DR: In this paper, a simple-to-use analytical solution for radial consolidation with vertical drains under equal strain conditions is presented, which accounts for the effects of soil smear, dra...
Abstract: A simple-to-use analytical solution for radial consolidation with vertical drains under equal strain conditions is presented in this paper. This solution accounts for the effects of soil smear, dra...
TL;DR: For more than 10 years, digital elevation models (DEM) produced by light detection and ranging (LIDAR) technology have provided new tools for geomorphologic studies and especially for landslide stu...
Abstract: For more than 10 years, digital elevation models (DEM) produced by light detection and ranging (LIDAR) technology have provided new tools for geomorphologic studies and especially for landslide stu...
TL;DR: In this article, the applicability of the power law model for the analysis of the rate-dependent rheological behavior of soils of different origins and characteristics was examined. The studied soils were divided into different types of soil types.
Abstract: The rate-dependent rheological behaviour of soils of different origins and characteristics was studied and the applicability of the power law model was examined. The studied soils were divided into...
TL;DR: In this article, self-desiccation is used to generate matric suction in Cemented Paste Backfill (CPB) backfill, which complicates determination of the water-retention curve and mechanical propert...
Abstract: Hydration occurring in cemented paste backfill (CPB) is shown to generate matric suction through self-desiccation. This complicates determination of the water-retention curve and mechanical propert...
TL;DR: In this article, the authors show that the injection of a calcium chloride solution followed by injection of sodium silicate solution during electroosmosis is effective in strengthening the ECS.
Abstract: Previous laboratory studies have shown that the injection of a calcium chloride solution followed by the injection of a sodium silicate solution during electroosmosis is effective in strengthening ...
TL;DR: Most of the seismic calculations currently used for the evaluation of seismic bearing capacity are formulated in terms of a linear Mohr-Coulomb failure criterion, however, experimental evidence suggests that the failure criterion may not be correct as discussed by the authors.
Abstract: Most of the seismic calculations currently used for the evaluation of seismic bearing capacity are formulated in terms of a linear Mohr–Coulomb failure criterion. However, experimental evidence sho...
TL;DR: In this paper, expanded polystyrene (EPS) geofoam seismic buffers are used to reduce earthquake-induced loads acting on rigid retaining wall structures and a numerical study is carried out to investigate the inf...
Abstract: Expanded polystyrene (EPS) geofoam seismic buffers can be used to reduce earthquake-induced loads acting on rigid retaining wall structures. A numerical study was carried out to investigate the inf...