Showing papers in "Canadian Geotechnical Journal in 1984"
TL;DR: Debris torrents, which are rapid flows of soil and organic debris down steep mountain channels, are a major natural hazard in many parts of British Columbia as discussed by the authors, and a series of recent occurrences along the
Abstract: Debris torrents, which are rapid flows of soil and organic debris down steep mountain channels, are a major natural hazard in many parts of British ColumbiaA series of recent occurrences along the
528 citations
TL;DR: In this article, scanning electron microscopy and mercury intrusion porosimetry were used in parallel to identify the structure of a medium sensitivity Champlain clay, and the structure was observed firstly on intac...
Abstract: Scanning electron microscopy and mercury intrusion porosimetry are used in parallel to identify the structure of a medium sensitivity Champlain clay. The clay structure is observed firstly on intac...
504 citations
TL;DR: The migration of salt solutions through remoulded, compacted clay in a laboratory physical model is compared with field migration through a similar but undisturbed clay located below a domes.
Abstract: The migration of salt solutions (NaCl) through remoulded, compacted clay in a laboratory physical model is compared with field migration through a similar but undisturbed clay located below a domes...
128 citations
126 citations
TL;DR: In this paper, the use of quantitative mineralogy and specific surface area in interpreting the index properties of clayey soils from nine sites in Eastern Canada is described, and samples representative of t...
Abstract: This paper describes the use of quantitative mineralogy and specific surface area in interpreting the index properties of clayey soils from nine sites in Eastern Canada. Samples representative of t...
117 citations
TL;DR: In many cases where fine-grained geologic materials are used as barriers to the migration of contaminated fluids, the principal mechanism of contaminant transport is molecular diffusion as discussed by the authors, and thus the e...
Abstract: In many cases where fine-grained geologic materials are used as barriers to the migration of contaminated fluids, the principal mechanism of contaminant transport is molecular diffusion. Thus the e...
116 citations
TL;DR: Two types of simple shear apparatus are in use as discussed by the authors, one developed at Cambridge, which is elaborately instrumented and accepts a cuboidal sample, and the other developed at the Norwegian Geotechnical Institute.
Abstract: Two types of simple shear apparatus are in use — one developed at Cambridge, which is elaborately instrumented and accepts a cuboidal sample, and the other developed at the Norwegian Geotechnical I...
96 citations
TL;DR: In this article, a procedure for calculating the amount of heave under a chilled gas pipeline is presented based on a finite-difference formulation of the heat and mass transfer in saturated soils.
Abstract: Frost heave is an important consideration in the design of buried chilled pipelines. A procedure for calculating the amount of heave under a chilled gas pipeline is presented based on a finite-difference formulation of the heat and mass transfer in saturated soils. The frost heave of the soil is characterized in terms of the segregation potential concept developed in earlier papers by the authors. Good agreement is found between the predictions of heave obtained with this procedure and that observed in long-term full-scale experiments at a test site in Calgary, Canada. Additional calculations are presented to explore the influence of pipeline temperature, pipe insulation, and ground temperature on frost heave of buried pipelines.
89 citations
TL;DR: Permeability tests were performed on materials of differing grain size and shape of gradation as discussed by the authors, and it was found that permeability was primarily dependent on and was practically independent of the shape of the gradients.
Abstract: Permeability tests were performed on materials of differing grain size and shape of gradation. It was found that permeability was primarily dependent on and was practically independent of the shape...
86 citations
TL;DR: In this paper, the authors present and discuss the factors that have been found relevant in the development of a representative laboratory simulation of the complex filtration phenomenon; namely, maximum particle size, density, saturation of the samples, direction of flow, intensity of the...
Abstract: Filter criteria have generally been checked experimentally with relatively uniform bases (protected soils). However, these criteria may not be applicable when nonuniform soils are used, especially broadly graded cohesionless tills with nonlinear grain size curves. Such soils were extensively used at the James Bay project as impervious core material, and a testing programme was undertaken to establish the margin of safety associated with the application of current filter criteria: the design was based on the arbitrarily defined portion of the base soil grain size curve. Also, a more general objective of the programme was to assess the role that self-filtration plays in the filtration process of such broadly graded cohesionless soils.This paper presents and discusses the factors that have been found relevant in the development of a representative laboratory simulation of the complex filtration phenomenon; namely, maximum particle size, density, saturation of the samples, direction of flow, intensity of the ...
58 citations
TL;DR: Gassy soils are defined as those soils which contain a relatively large amount of gas dissolved in the pore fluid as discussed by the authors, i.e., gassy soil is defined as soil which contain relatively large amounts of gas.
Abstract: Gassy soils are defined as those soils which contain a relatively large amount of gas dissolved in the pore fluid. Examples include the Alberta Oil Sands, marine sediments from deep ocean locations...
TL;DR: The lateral earth force calculation using the limit equilibrium method of slices is an indeterminate problem as discussed by the authors, and an assumption regarding the direction or the magnitude of certain forces, or the...
Abstract: The calculation of the lateral earth force using the limit equilibrium method of slices is an indeterminate problem. An assumption regarding the direction or the magnitude of certain forces, or the...
TL;DR: In this article, a finite element analysis of two instrumented sections of a geotextile-reinforced embankment constructed on peat is presented, and the results from the analysis provide very encouraging conclusions.
Abstract: This paper describes a finite element analysis of two instrumented sections of a geotextile-reinforced embankment constructed on peat. The results from the analysis provide very encouraging agreeme...
TL;DR: In this article, the authors used the tangent modulus approach to measure the pore pressure and direct permeability of fibrous peat blocks in two different sites in the James Bay territory in Quebec.
Abstract: Intact block samples of fibrous peat have been obtained using special equipment from two different sites in the James Bay territory in Quebec. Instrumented test fills were subsequently built at those two sites and the observed behaviour was used to check the laboratory data. The laboratory testing program has included standard 24 h incremental tests and stage creep tests where constant loads were applied for periods of about 30 d. Pore pressure and direct permeability measurements were conducted in most of the tests.The tests have been interpreted using the classical e − log p curves or the tangent modulus approach. The evaluation of compression with time under a constant load has allowed the distinction between primary and secondary consolidation. A certain lag in pore pressure response has been observed and related to incomplete saturation. The coefficient of permeability decreases rapidly with compression as indicated by direct measurements and pore pressure dissipation.The comparison with field observ...
TL;DR: In this paper, the ultimate bearing capacity of rigid piles and pile groups in clay has been determined under various combinations of e cient combinations of rigid and non-rigid materials.
Abstract: In connection with the design of offshore structures and bridge foundations, the ultimate bearing capacity of rigid piles and pile groups in clay has been determined under various combinations of e...
TL;DR: In this paper, the failure envelopes of many soils are significantly nonlinear and the effect of this curvature on slope stability is examined, and charts based on circular arc stability analyses have been prepared.
Abstract: The failure envelopes of many soils are significantly nonlinear and the effect of this curvature on slope stability is examined. Charts, based on circular arc stability analyses, have been prepared...
TL;DR: In this paper, the Jebba Hydroelectric Development, Nigeria, presently under construction, features a 42'm high zoned rockfill embankment founded on river alluvium up to 70'm in depth.
Abstract: The Jebba Hydroelectric Development, Nigeria, presently under construction, features a 42 m high zoned rockfill embankment founded on river alluvium up to 70 m in depth. The riverbed alluvium comprises fine- to medium- to coarse-grained, quartzitic sands with traces of gravel. The relative densities of the sands vary appreciably in both the vertical and horizontal directions. During the dam design it was found that it would be necessary to densify the loose to medium dense portion of the river sands to maintain settlements within acceptable limits and to withstand design earthquake forces. The top 25 m of the river alluvium is densified by the vibrocompaction method, and below this level down to depths of 40 m the alluvium is densified by blasting. There is no precedent found in the literature for densification by blasting at such depth. This paper presents details of a test program and the production work. Test results conclusively show increases in static cone penetration resistance in loose sand layers...
TL;DR: In this paper, the authors present results from a field investigation in which groundwater pressures were measured in a natural slope of soft clay over a 10-year period, together with calculated annual changes of safety factor of the slope.
Abstract: This paper presents results from a field investigation in which groundwater pressures were measured in a natural slope of soft clay over a 10 year period. Measurements of piezometric levels are reported together with calculated annual changes of safety factor of the slope.Using consolidation theory, predictions were made of changes of piezometric levels for the condition of zero infiltration based on the postulate that these changes were the direct result of changes of hydraulic conditions at the ground surface. The predictions were in agreement with the field measurements.A method is suggested for estimating the most severe groundwater pressures that a clay slope can be expected to experience. Using this method, estimates were made of the minimum expected value of safety factor of the slope at the test site. Keywords: natural slope, clay, pore pressures, field measurements, stability, long-term.
TL;DR: In this article, the authors outline the ultimate and serviceability limit states in geotechnical engineering analyses and the magnitude of customary total and suggested partial safety factors in earthworks, earthworks and earth ret...
Abstract: This paper outlines the ultimate and serviceability limit states in geotechnical engineering analyses. The magnitude of customary total and suggested partial safety factors in earthworks, earth ret...
TL;DR: In this paper, the authors describe the results of 34 creep tests and 11 time-dependent strength tests carried out on saline soils for two different research programs; consequently, two different fine-grained soil types were used.
Abstract: Little creep data is available for frozen, fine-grained saline soils. Salinity accelerates the creep rate of a frozen soil under load and reduces its shear strength owing to the higher unfrozen water contents in the pore phase. Creep data for saline fine-grained soils are required by engineers and scientists working in areas of coastal or offshore permafrost. The data are also used in projects involving artificial freezing of saline soils.This paper describes the results of 34 creep tests and 11 time-dependent strength tests carried out on saline soils. The tests were carried out for two different research programs; consequently, two different fine-grained soil types were used. Most of the tests were carried out in a constant stress and constant temperature creep test environment. Some were completed in a triaxial (constant strain rate) test format, in order to extend the data base to an area of higher strain rates. The range of temperatures was −2.3 to −25 °C, the range of stresses in the creep tests was...
TL;DR: In this paper, a model is proposed to describe continuous flow between saturated and unsaturated soil, where the flow is assumed to be two dimensional and under steady state conditions in the unsaturated zone, the coef
Abstract: A model is proposed describing continuous flow between saturated and unsaturated soil The flow is assumed to be two dimensional and under steady state conditions In the unsaturated zone, the coef
TL;DR: In this article, the geochemical mass transfer model WATEGM-SE is used to illustrate potential chemical reactions that can occur at a hypothetical low-temperature thermal energy aquifer storage facility.
Abstract: The geochemical mass transfer model WATEGM-SE is used to illustrate by example potential chemical reactions that can occur at a hypothetical low-temperature thermal energy aquifer storage facility....
TL;DR: In this article, the design, instrumentation, and field performance of two instrumented sections of a geotextile-reinforced embankment are described, where a polypropylene, monofilament woven fabric (Permealiner 1195) was used to reinforce the embankments over the less compressible section of the peat deposit.
Abstract: The design, instrumentation, and field performance of two instrumented sections of a geotextile-reinforced embankment are described. The 1–1.5 m high embankment was constructed in three stages on top of a peat deposit that extended to depths of up to 7.6 m. The peat was highly compressible with average water contents of 445% and 785% at the two instrumented sections.A polypropylene, monofilament woven fabric (Permealiner 1195) was used to reinforce the embankment over the less compressible section of the deposit. At stage I, 1.37 m of fill resulted in settlements of approximately 1 m but only 1% transverse strain in the geotextile. At stage II, a total of 3.87 m of fill had been added with total settlements of approximately 3 m and transverse geotextile strain of 21%. Stage III construction involved bringing the embankment to final grade, with a total fill and pavement thickness of 4.2 m. Settlements at stage III were relatively small.A strong, twisted, slit film, polypropylene woven fabric (Geolon 1250) ...
TL;DR: In this article, the strength of the moss layer and tree roots was evaluated by performing tension tests on the roots and the moss-root complex, and the results of stability analyses showed that local failures involving individual wedges are likely.
Abstract: Many north-facing slopes in the Yukon–Tanana Uplands of Alaska show signs of downhill movements in the form of hummocky surface and leaning trees. Measurements of movements and pore pressures were made at several sites in the Caribou–Poker Creek Research Watershed. It was found that, on slopes with inclinations near 30°, most of the movements occurred immediately after thaw when pore pressures were high.To evaluate the slope stability, the soil strength was measured by direct shear tests. The strength of the moss layer and tree roots was evaluated by performing tension tests on the roots and the moss–root complex. Results of stability analyses show that local failures involving individual wedges are likely. The displacements associated with a wedge slide would result in a hummock or step. The strength of the moss–root complex was found to be a significant factor in the stability of the wedge and of the step. Key words: moss, roots, permafrost, pore pressure, shear strength, slope stability, thaw.
TL;DR: In this article, a simple method of analysis for predicting the response of piles and casings to horizontal free-field soil displacements is presented, which involves a modification to the conventional laterally loaded pile problem to account for the load induced by the free field deflections.
Abstract: A simple method of analysis for predicting the response of piles and casings to horizontal free-field soil displacements is presented. Such free-field displacements can be induced in the soil by ice or earthquake loading and can damage piles or casings within the soil. The method involves a modification to the conventional laterally loaded pile problem to account for the load induced by the free-field deflections.The method is applied to analyze the response of a casing within a caisson-retained island subject to high ice loading. The results indicate that flexible casings essentially track with the soil and are subjected to low forces and moments, whereas stiff casings deflect as a rigid body and attract high forces and moments.
TL;DR: In this article, five horizontal drains were installed in a natural clay slope and the piezometric heads in the slope were monitored with piezometers, and the results indicated that horizontal drains can be used to improve the stability of clay slopes.
Abstract: Five horizontal drains were installed in a natural clay slope and the piezometric heads in the slope were monitored with piezometers. Decreases of piezometric head in the vicinity of the drains were measured and indicated that horizontal drains can be used to improve the stability of clay slopes.Based on the theory of consolidation, estimates were made of the changes of piezometric head within the test slope due to the installation of drains. Good comparisons were obtained between the predicted and the measured values, demonstrating that the method of prediction can be used with confidence for design purposes. The three-dimensional pattern of piezometric levels was averaged to give an equivalent two-dimensional pattern, and this was used in slope stability calculations to determine the improvement in safety factor of the slope.The effectiveness of horizontal drains depends on the spacing and diameter of the drains, and on their location relative to the critical slip zone.The study has shown that installat...
TL;DR: In this article, the effects on stability of concentrated downward and upward influence loads acting at successive positions between the head and toe of a landslide with a fixed failure surface are expressed in terms of influence lines for the resultant changes in the factor of safety.
Abstract: The effects on stability of concentrated downward and upward influence loads acting at successive positions between the head and toe of a landslide with a fixed failure surface are expressed in terms of influence lines for the resultant changes in the factor of safety. Of particular importance are the positions where no change in factor of safety is produced. On a slope section these are referred to as "neutral points": the traces of these in plan are termed "neutral lines." These concepts provide valuable guidance on the most effective locations and distributions of corrective cuts and fills, particularly for slides on pre-existing slip surfaces.Stabilization of slides by loading the toe is shown to be generally preferable to unloading the head. In complex slides, corrective cuts and fills are best restricted to the extreme head and toe positions, intermediate cuts or fills being avoided.The conditions are defined under which the flattening of slopes by the removal of material reduces stability. In certa...
TL;DR: The results of laboratory and in situ testing and test blasting, the observations made on a test embankment, and a description of actual construction practice associated with engineering studies are described in this paper.
Abstract: The results of laboratory and in situ testing and test blasting, the observations made on a test embankment, and a description of actual construction practice associated with engineering studies fo...
TL;DR: In this paper, a theory for the design of laterally loaded piles in permafrost is presented, valid for icy soils or ice, where secondary creep displacements will be responsible for the majority of...
Abstract: A theory for the design of laterally loaded piles in permafrost is presented. The approach is valid for icy soils or ice, where secondary creep displacements will be responsible for the majority of...
TL;DR: In this paper, a case history from the Revelstoke Hydroelectric Project, British Columbia, is used to demonstrate that these internal shears were required for movement to occur and that passive anchors inside the sliding rock mass can be used to improve the overall slope stability.
Abstract: A class of rock slope failures exists in which the mode of failure requires the existence or creation of internal shears to accommodate large internal slide mass distortion. These internal displacements are required to allow motion along the basal slip surface. This paper demonstrates that the more traditional limit equilibrium methods of analysis are often conservative when used to assess the stability of slopes with this failure mechanism. As a result, back analysis may overestimate the available shear resistance. A method of analysis capable of handling this failure mechanism was proposed by S. K. Sarma. A case history from the Revelstoke Hydroelectric Project, British Columbia, is used to demonstrate that these internal shears were required for movement to occur and that passive anchors inside the sliding rock mass can be used to improve the overall slope stability. No attempt is made to evaluate the actual factor of safety of the three-dimensional slide mass. Key words: rock slope, foliation shear, s...