Showing papers in "Canadian Geotechnical Journal in 1986"
TL;DR: In this article, a comparison of the results of laboratory model tests used to study the bearing capacity of geogrid and geotextile reinforced earth slabs is presented. The parameters studied were the coeffi...
Abstract: Presented herein is a comparison of the results of laboratory model tests used to study the bearing capacity of geogrid and geotextile reinforced earth slabs. The parameters studied were the coeffi...
254 citations
TL;DR: In this paper, a model for the behavior of flow slides in loose, cohesionless materials in which the debris spreads out as a uniform sheet is proposed, and excess porefluid pressures are assumed to be generated.
Abstract: A model is proposed for the behaviour of flow slides in loose, cohesionless materials in which the debris spreads out as a uniform sheet. Excess pore-fluid pressures are assumed to be generated, fo...
228 citations
201 citations
TL;DR: In this paper, the sudden release of water impounded in natural and man-made reservoirs has been responsible for some major disasters in mountainous regions of the world, such as floods and dams failure.
Abstract: The sudden release of water impounded in natural and man-made reservoirs has been responsible for some major disasters in mountainous regions of the world. Recent natural damming events and failure...
158 citations
TL;DR: The U.S. Geological Survey used a recently developed heat-pulse flowmeter to measure very slow borehole axial water velocities in granitic rock at a site near Lac du Bonnet, Manitoba, Canada.
Abstract: The U.S. Geological Survey used a recently developed heat-pulse flowmeter to measure very slow borehole axial water velocities in granitic rock at a site near Lac du Bonnet, Manitoba, Canada. The f...
143 citations
TL;DR: In this article, an unweathered glacial till was found to have a bulk permeability that exceeds its matrix permeability by two orders of magnitude and a mean specific storage of 1.3 × 10−4 m−1.
Abstract: Field and laboratory studies of a clayey unweathered glacial till have shown that its bulk permeability exceeds its matrix permeability by two orders of magnitude. Such findings are common for weathered till but are rare for unweathered till, and have important implications for groundwater recharge and contaminant transport. The till in question is 6 m thick and appears to be unweathered and unfractured. It is overlain by 12 m of weathered and highly fractured till. Results of consolidation tests on the unweathered till indicate a mean vertical hydraulic conductivity of 3.5 × 10−11 m∙s−1 and a mean specific storage of 1.3 × 10−4 m−1. Results of slug tests yield a horizontal hydraulic conductivity of about 5 × 10−9 m∙s−1. Drawdowns in the till in response to pumping from the aquifer below indicate a vertical hydraulic diffusivity of 4.5 × 10−5m2∙s−1. The slug test results combined with specific storage results from consolidation tests indicate a similar value for horizontal hydraulic diffusivity of 4 × 10−...
127 citations
TL;DR: The liquid and plastic limits for a variety of natural and artificial soils covering a wide range of plasticity, as determined by the Casagrande method and the fall cone test and based on a strengt...
Abstract: The liquid and plastic limits for a variety of natural and artificial soils covering a wide range of plasticity, as determined by the Casagrande method and the fall cone test and based on a strengt...
106 citations
TL;DR: The Canadian concept for disposing of nuclear fuel waste, currently being studied by Atomic Energy of Canada Limited (AECL) and Ontario Hydro, is to permanently place the waste in an underground va...
Abstract: The Canadian concept for disposing of nuclear fuel waste, currently being studied by Atomic Energy of Canada Limited (AECL) and Ontario Hydro, is to permanently place the waste in an underground va...
102 citations
TL;DR: In this paper, the shear stress transmitted by water to the clay surface is directly and accurately derived and the dry weight of eroded material per unit time and unit area, for given conditions, is also directly and adequately measured.
Abstract: The methods developed to predict the action of eroding fluid on cohesive soils lead to contradictory predictions. Most of them are questionable since they ignore the physicochemical parameters that seem to control the erosion process. In order to study the scour resistance of intact or remolded cohesive soils, a rotating cylinder technique allowing for the control of essential parameters was recently improved by the authors. Intact or remolded samples can be used. The water quality is controlled in order to respect the in situ physicochemical conditions. The shear stress transmitted by water to the clay surface is directly and accurately derived. The dry weight of eroded material per unit time and unit area, for given conditions, is also directly and adequately measured. The influence of water quality, or of any treatment of the clay, may be quantitatively analyzed.
56 citations
TL;DR: In this article, the status of in situ testing and its application to foundation engineering are presented and discussed within the framework of three groups: logging, specifiability, and testing.
Abstract: The status of in situ testing and its application to foundation engineering are presented and discussed. The in situ test methods are discussed within the framework of three groups: logging, specif...
56 citations
TL;DR: In this article, the prediction of stress changes and deformations arising from ground heating requires the coupled solution of the heat transfer and consolidation equations, which is a class of problems in the literature.
Abstract: The prediction of stress changes and deformations arising from ground heating requires the coupled solution of the heat transfer and consolidation equations. Heat consolidation as a class of proble...
TL;DR: In this paper, a stage-constructed embankment on soft clay in the centrifuge was constructed on a clay foundation consisting of an overconsolidated crust overlying a normally consolidated layer, and measurements were taken of pore pressures, dissipation rates, and displacements in the foundation clay.
Abstract: Biot coupled consolidation numerical analyses have been applied to a stage-constructed embankment on soft clay in the centrifuge. In the test, the sand embankment was constructed on a clay foundation consisting of an overconsolidated crust overlying a normally consolidated layer. Measurements were taken of pore pressures, dissipation rates, and displacements in the foundation clay. Predictions of these were made using a simple Cam-clay model for the clay and the Cambridge CRISP computer program. A linear elastic idealization was used for the embankment. With some exceptions, pore pressures and dissipation rates were very well predicted, as were maximum values of both horizontal and vertical displacements. However, displacement profiles with depth were not so well predicted. Particular attention is given in the paper to the determination of relevant values of shear modulus G and the difference in behaviour resulting from using constant permeability and permeability varying with void ratio.
TL;DR: In this paper, four case histories where important changes in pile capacity were observed with time are presented and two show an increase of pile capacity for shaft bearing piles driven into deep sand deposits.
Abstract: Four case histories where important changes in pile capacity were observed with time are presented. Two show an increase of pile capacity for shaft bearing piles driven into deep sand deposits. The...
TL;DR: In this article, the pull-out capacity of single rigid vertical and batter piles in sand and subjected to axial loading was investigated and good agreement was found when test results on instrumented model piles were obtained.
Abstract: The pull-out capacity of single rigid vertical and batter piles in sand and subjected to axial loading has been investigated. Good agreement was found when test results on instrumented model piles ...
TL;DR: In this paper, the authors examine the deepening of valleys in Champlain clay deposits of Eastern Canada and in particular look at the changes in the groundwater regime and slope stability conditions during valley formation.
Abstract: The purposes of the paper are to examine the deepening of valleys in clay deposits of Eastern Canada and in particular to look at the changes in the groundwater regime and slope stability conditions during valley formation. Field observations and laboratory testing indicate that the rate of valley deepening in Champlain clay deposits is of the order of only a few millimetres a year, owing to the low erodibility of the intact clay. The clay banks are, however, more erodible, owing to alteration and fissuration.The stratigraphy of Eastern Canadian clay deposits can be simplified by considering it to be a stratum of low permeabilityconfined between two boundary layers of relatively high permeability, which are the till layer at the base and a weathered crust or coarse-grained layer at the top. As the valley bottom get closer to the bottom till layer, the groundwater regime, and consequently the stability conditions, are modified. During the process of valley formation, the groundwater regime passes through a...
TL;DR: In this paper, the authors present an approach to the use of electomagnetic geophysical methods for delineating groundwater contamination, and test the concepts at three waste disposal sites at three Waste Disposal Sites.
Abstract: We present an approach to the use of electomagnetic geophysical methods for delineating groundwater contamination, and test the concepts at three waste disposal sites. The approach includes a technique for modelling a site's response to a variety of instruments, and a device-independent method of contouring the data. The modelling attempts to account for the noise inherent in the measurement process, particularly the effects of lateral variations in stratigraphy. These concepts are evaluated by comparing the geophysical response to groundwater conductivities measured in sampling wells. We conclude that geophysics offers a cost-effective supplement to drilling, and that it is best used in a reconnaissance mode to map the general distribution of contamination prior to a detailed sampling program. The correlation between the observed and predicted geophysical response as a function of groundwater conductivity is as good as can be expected given the uncertainties in the process. The methodology proposed is si...
TL;DR: In this article, the most important factors governing piping were permeability and capillary suction in sand seams, slope of sand seams and water in tension cracks behind the bank face Flood hydrograph parameters (height of rise and duration of event) were less important.
Abstract: Erosion of alluvial stream banks is of scientific and economic significance The principal focus of this investigation was stream bank erosion caused by piping of sand seams, which leads to collapse of overlaying strata Analyses were performed to determine which parameters of the riverbank system are most important in controlling the amount and rate at which piping occurs Among the failure mechanisms studied were wedge failure of large masses and surficial shearing (slabbing failure) of bank faces Analyses showed that the most important factors governing piping were permeability and capillary suction in sand seams, slope of sand seams, and water in tension cracks behind the bank face Flood hydrograph parameters (height of rise and duration of event) were less important, though significant Whereas unit weight, cohesion, angle of internal friction, and water in tension cracks influenced wedge failures, only unit weight and cohesion directly influenced slabbing failures; however, those parameters influencing piping indirectly also influenced slabbing failures Results of the analyses agreed closely with field observations
TL;DR: In this paper, the seasonal variation of thermal conductivity of the ground at depths within the seasonally active freezing/thawing zone is presented for a number of different soil conditions at four sites across Canada.
Abstract: Data representing the seasonal variation of thermal conductivity of the ground at depths within the seasonally active freezing/thawing zone are presented for a number of different soil conditions at four sites across Canada. An inexpensive probe apparatus suitable for routine field measurements is described.In all the cases examined, significant seasonal variations were confined to the first few decimetres. In addition to distinct seasonal differences associated with phase change, quite large changes occurred during the period when the soil was thawed in those cases where seasonal drying was possible. Below the seasonally active zone, thawed soil conductivities did not differ greatly among the three nonpermafrost sites in spite of soil composition ranging from marine clay to sandy silt. The data suggest that, even within a given soil layer, quite significant differences in thermal conductivity may be encountered in engineering structures such as embankments, presumably because of differences in drainage c...
TL;DR: An in situ analysis of naturally occurring creep has been carried out at the proposed Canadian Arctic Gas pipeline crossing of Great Bear River in the Northwest Territories as mentioned in this paper, which is the third of its kind.
Abstract: An in situ analysis of naturally occurring creep has been carried out at the proposed Canadian Arctic Gas pipeline crossing of Great Bear River in the Northwest Territories. This is the third of fo...
TL;DR: In this paper, a set of coal shales associated with coal measure strata has been examined to determine the mechanisms that lead to slaking on immersion in water, and two main mechanisms for the slaking of small unconfined samples are (a) compression of entrapped air and (b) osmotic swelling of expansive clay minerals if the dominant exchangeable cation is sodium.
Abstract: A set of clay shales associated with coal measure strata has been examined to determine the mechanisms that lead to slaking on immersion in water. The two main mechanisms for the slaking of small unconfined samples are (a) compression of entrapped air and (b) osmotic swelling of expansive clay minerals if the dominant exchangeable cation is sodium. In the absence of osmotic swelling, pore-air compression can induce slaking in clay shales of bulk densities less than 2.27 Mg/m3. Osmotic swelling of clay shales occurs in samples with bulk densities less than about 2.45 Mg/m3, but slaking by this mechanism occurs only for samples with densities less than 2.34 Mg/m3. Dispersion of clay from clay shales develops only after slaking commences, and the extent of dispersion depends on the nature of the interparticle bonds. Key words: clay shales, clays, coal measure rocks, slaking, dispersion, porosity, density.
TL;DR: In this article, a tentative classification of erosion processes is proposed, focusing on the scour process of clayey soils, including various types of erosive actions, such as erosion of clayy soils.
Abstract: The erosion of clayey soils is a complex phenomenon that includes various types of erosive actions. A tentative classification of erosion processes is proposed. This paper concentrates on the scour...
TL;DR: In this article, the equations of statical equilibrium and the failure criterion for the soil are insufficient to render a slope stability analysis determinate, and the problem is resolved by making assumpti...
Abstract: The equations of statical equilibrium and the failure criterion for the soil are insufficient to render a slope stability analysis determinate. Generally, the problem is resolved by making assumpti...
TL;DR: In this paper, the need for better inventories of peat as an energy fuel becomes increasingly important, and conventional imaging sensors can provide information about peat resources, but they cannot provide information o...
Abstract: With the growing interest in peat as an energy fuel, the need for better inventories of this resource becomes increasingly important. Although conventional imaging sensors can provide information o...
TL;DR: In this article, Flexibility coefficients of single piles and interaction factors established for groups of two piles are presented to facilitate analysis of arbitrary pile groups exposed to static horizontal loads, and the interaction factors are established for two piles groups.
Abstract: Flexibility coefficients of single piles and interaction factors established for groups of two piles are presented to facilitate analysis of arbitrary pile groups exposed to static horizontal loads...
TL;DR: In this paper, a new stress characteristic solution has been developed for two-dimensional strip footings on the surface of a sand layer using sand properties defined by a critical state model, taking account of different stress levels, different placement densities, the sand compressibility, and the transition from strain softening to strain hardening behavior that accompanies increased stresses.
Abstract: A new stress characteristic solution has been developed for two-dimensional strip footings on the surface of a sand layer. The analysis uses sand properties defined by a critical state model. This analysis takes account of different stress levels, different placement densities, the sand compressibility, and the transition from strain softening to strain hardening behavior that accompanies increased stresses. The results show linear relationships between log (Nγ) and log (footing breadth) that depend on the details of the sand model used. The results have been compared with available summaries of laboratory- and field-scale results. Although the critical state models for the sands used in the experimental studies cannot be fully developed from published information, nevertheless the trend of the results is encouraging. Additional information on validations of the critical state sand model is needed. Key words: surface footings, stability, capacity coefficients, self-weight, plasticity, stress characteristi...
TL;DR: An in situ analysis of naturally occurring creep has been carried out at the proposed Canadian Arctic Gas pipeline crossing of Great Bear River in the Northwest Territories as mentioned in this paper, which is the last of fou...
Abstract: An in situ analysis of naturally occurring creep has been carried out at the proposed Canadian Arctic Gas pipeline crossing of Great Bear River in the Northwest Territories. This is the last of fou...
TL;DR: The results of a recent in situ testing program to establish standard penetration test -cone penetration test (SPT-CPT) correlation for the windblown calcareous desert sands of Kuwait are presente...
Abstract: The results of a recent in situ testing program to establish standard penetration test – cone penetration test (SPT–CPT) correlation for the windblown calcareous desert sands of Kuwait are presente...
TL;DR: In this paper, a technique for sealing and storing clay samples so as to prevent aging effects during long periods of storage is described, and the results of a study carried out on samples store...
Abstract: This note describes a technique for sealing and storing clay samples so as to prevent aging effects during long periods of storage. It also gives the results of a study carried out on samples store...