Showing papers in "Canadian Geotechnical Journal in 2017"
TL;DR: An overview of the tools and methods that are currently available and discusses some of the main challenges that are being addressed by researchers, including the need for better guidance in the selection of model input parameter values, the challenge of translating model results into vulnerability estimates, the problem with too much initial spreading in the simulation of certain types of landslides, the difficulty of accounting for sudden channel obstructions, an... as discussed by the authors.
Abstract: Flow-like landslides, such as debris flows and rock avalanches, travel at extremely rapid velocities and can impact large areas far from their source. When hazards like these are identified, runout analyses are often needed to delineate potential inundation areas, estimate risks, and design mitigation structures. A variety of tools and methods have been developed for these purposes, ranging from simple empirical–statistical correlations to advanced three-dimensional computer models. This paper provides an overview of the tools and methods that are currently available and discusses some of the main challenges that are currently being addressed by researchers, including the need for better guidance in the selection of model input parameter values, the challenge of translating model results into vulnerability estimates, the problem with too much initial spreading in the simulation of certain types of landslides, the challenge of accounting for sudden channel obstructions in the simulation of debris flows, an...
134 citations
TL;DR: In this paper, the authors focus on semi-rigid piles, whose pile-soil stiffness lies between 2.5 and 3.5 degrees of freedom from the ground plane.
Abstract: Previous studies on laterally loaded piles in clay have mainly focused on flexible and rigid piles. Little attention has been paid to semi-rigid piles (whose pile–soil stiffness lies somewhere betw...
125 citations
TL;DR: In this article, a flexible model barrier together with a rigid barrier were used to simulate either dry granular or viscous liquid impacts on these model barriers in a geotechnical centrifuge.
Abstract: Structural countermeasures such as rigid and flexible barriers are commonly installed in mountainous regions to intercept mass-wasting processes. Without sufficient and reliable comparable physical data, the study of impact mechanisms remains difficult and not well understood. In this study, a newly developed flexible model barrier together with a rigid barrier are used to simulate either dry granular or viscous liquid impacts on these model barriers in a geotechnical centrifuge. The novel flexible barrier is made of four instrumented cables controlled by spring mechanisms to replicate a bilinear prototype loading response. Tests revealed that regardless of barrier type, both dry granular and viscous flows could have similar frontal dynamic impact coefficients around unity. Compared with the kinetic energy of flow mass (∼10 MJ), only 249 kJ of flexible barrier energy capacity was mobilized. This implies that debris-resisting barriers may only be required to intercept the dynamic flow front as the subseque...
91 citations
TL;DR: The dynamics of debris flows are fundamentally governed by the interaction between the solid and fluid phases, and current approaches used to estimate impact load treat debris flow as an equivocal process.
Abstract: The dynamics of debris flows are fundamentally governed by the interaction between the solid and fluid phases. However, current approaches used to estimate impact load treat debris flow as an equiv...
91 citations
TL;DR: The effects of Vetiver grass (Chrysopogon zizanioides) roots on the soil-water retention curves (SWRCs), permeability (k) function, and saturated permeability, ksat, have been investigated on claye...
Abstract: The effects of Vetiver grass (Chrysopogon zizanioides) roots on the soil-water retention curves (SWRCs), permeability (k) function, and saturated permeability, ksat, have been investigated on claye...
90 citations
TL;DR: For the French conventional railway lines, a layer, namely interlayer, was created in the substructure mainly by the interpenetration of ballast grains and subgrade soils.
Abstract: For the French conventional railway lines, a layer, namely interlayer, was created in the substructure mainly by the interpenetration of ballast grains and subgrade soils. The in situ investigation...
70 citations
TL;DR: In this article, the authors quantitatively assess the impact of extreme precipitation events under current and future climate scenarios on landslides, and analyze the effect of extreme rainfall on these landslides.
Abstract: This study aims to quantitatively assess the impact of extreme precipitation events under current and future climate scenarios on landslides. Rainfall-triggered landslides are analyzed primarily us...
69 citations
TL;DR: In this article, a soil-pile interaction model is developed to better represent the actual behavior of pipe piles undergoing dynamic testing, and the model is used to correctly investigate the dynamic interaction mechanism of the pipe p...
Abstract: A soil–pile interaction model is developed to better represent the actual behavior of pipe piles undergoing dynamic testing. To correctly investigate the dynamic interaction mechanism of the pipe p...
68 citations
TL;DR: Coral sand has individual characteristics that differ from silica sand, such as creep behavior that is always attributed to particle crushing under high stress states as discussed by the authors, and the creep behavior can be explained by particle crushing.
Abstract: Coral sand has individual characteristics that differ from silica sand, such as creep behavior that is always attributed to particle crushing under high stress states. To understand the creep behav...
60 citations
TL;DR: In this article, the authors presented a simplified hypothesis B method for calculation of consolidation settlement of a clayey soil with creep, based on the equivalent time concept for different stress-strain states.
Abstract: The calculation of the consolidation settlement of clayey soils with creep behaviour has been a challenging issue with a long history. After a brief review the assumptions made in the two methods based on Hypothesis A and Hypothesis B, the authors present a new simplified hypothesis B method for calculation of consolidation settlement of a clayey soil with creep. Equations of this method are derived based on the “equivalent time” concept for different stress–strain states. This simplified Hypothesis B method is then used to calculate the consolidation settlement of a number of typical consolidation problems. The approximation and verification of this simplified method are examined by comparing the calculated settlements with settlements computed using two fully coupled finite element (FE) consolidation analysis programs using elastic viscoplastic (EVP) constitutive models (Hypothesis B) and the Hypothesis A method. It is found that the curves calculated using the new Hypothesis B simplified method with a ...
58 citations
TL;DR: In this article, the shear behavior of intact soil was studied at different suctions and temperatures. But, the focus was mainly on recompacted soils and only limited attention has been paid to intact soil.
Abstract: Previous studies of shear behaviour at different suctions and temperatures focused mainly on recompacted soils. Limited attention has been paid to intact soil. In this paper, the shear behaviour of...
TL;DR: A series of undrained monotonic and cyclic triaxial tests were performed on silica sand at two initial densities and different confining pressures from 0.1 to 5 MPa to investigate their shear respo...
Abstract: A series of undrained monotonic and cyclic triaxial tests were performed on silica sand at two initial densities and different confining pressures from 0.1 to 5 MPa to investigate their shear respo...
TL;DR: In this article, rainfall and reservoir water level fluctuations are the main external factors of landslides in the Three Gorges Reservoir area, and they improved the analysis of slope stability under the combined effect of rainfall and reservoir level fluctuations.
Abstract: Rainfall and reservoir water level fluctuations are the main external factors of landslides in the Three Gorges Reservoir area. To improve the analysis of slope stability under the combined effect ...
TL;DR: In this article, the authors studied how mixed-species planting would affect plant growth and induced matric suction for a single species and showed that it is possible to induce matric-suction for multiple species.
Abstract: Although evapotranspiration-induced matric suction for single species has been widely studied, little is known about how mixed-species planting would affect plant growth and induced matric suction....
TL;DR: In this article, a new analytical solution for undrained expansion of spherical and cylindrical cavities in soils with a unified state parameter model for clay and sand (CASM) is presented.
Abstract: This paper presents a new analytical solution for undrained expansion of spherical and cylindrical cavities in soils with a unified state parameter model for clay and sand (CASM). Large strain and effective stress solutions are derived for soils in the elastic, plastic and critical-state regions. The key advantage of using the state parameter model CASM is that it can model both clay and sand and is generally able to capture overall soil behaviour as observed in the laboratory. The newly developed solution provides the stress and strain fields during the expansion of a cavity from an initial to a final radius. Following the validation with the original Cam Clay solution, a simple parametric study is conducted to investigate the effects of key model parameters on stress distributions and cavity expansion curves. Applications to the analysis of pile installation and self-boring pressuremeter tests highlight some important implications in geotechnical practice.
TL;DR: In this paper, a new water retention model accounting for proper retention mechanisms in each structural level of compacted bentonites, namely adsorption in the intra-aggregate pores and capillarity in the interaggregate ones, is presented.
Abstract: The water retention behaviour of compacted bentonites is strongly affected by multi-physical and multi-scale processes taking place in these materials. Experimental data have evidenced major effects of the material dry density, the imposed volume constraints, and the soil fabric. This paper presents a new water retention model accounting for proper retention mechanisms in each structural level of compacted bentonites, namely adsorption in the intra-aggregate pores and capillarity in the inter-aggregate ones. The model is calibrated and validated against experimental data on different bentonite-based materials, showing good capabilities in capturing the main features of the behaviour. The model is able to reproduce experimental data on compacted bentonites over a wide range of suction values, within a unified framework, and using a limited number of parameters. Some of the parameters introduced are shown to take approximately the same value for several bentonites, providing a significant basis for prelimin...
TL;DR: In this article, fly ash was solidified as a byproduct from the incineration of municipal solid waste (MSW), and it usually contains mobile heavy metals that may engender severe pollution when reused.
Abstract: As a by-product from the incineration of municipal solid waste (MSW), fly ash usually contains mobile heavy metals that may engender severe pollution when reused. In this study, fly ash was solidif...
TL;DR: In this paper, the authors introduced the Rock Quality Designation (RQD) as a means of using diamond core to classify rock for engineering purposes and incorporated it into the ro...
Abstract: Rock quality designation (RQD) was introduced by Don Deere in the mid-1960s as a means of using diamond core to classify rock for engineering purposes. Subsequently, it was incorporated into the ro...
TL;DR: In this paper, post-construction data from an instrumented geosynthetic reinforced column supported embankment (GRCSE) on drilled displacement columns in Melbourne, Australia, show the time-dependent development of the columns.
Abstract: Post-construction data from an instrumented geosynthetic reinforced column supported embankment (GRCSE) on drilled displacement columns in Melbourne, Australia, show the time-dependent development ...
TL;DR: In this article, an integrated framework for geostatisical analyses, which incorporates the restricted maximum likelihood (REML) method with the Matern autocovariance model, is presented.
Abstract: Despite recent efforts to characterize the uncertainties involved with geological profiles and soil and rock properties, there has been limited study on their spatial correlations and how such features may be included in the engineering decision-making process. This paper presents an integrated framework for geostatisical analyses, which incorporates the restricted maximum likelihood (REML) method with the Matern autocovariance model. Statistical tests are conducted including those for data normality, constant variance, and outliers, which ensure the fundamental assumptions of REML are not violated in the residual analyses of site data, meanwhile offering simple checks for potential errors in the dataset. The proposed approach also allows quantification of uncertainties in the subsurface profiles at the unsampled locations. The approach is illustrated through investigations on spatial correlation features of geological profiles at two project sites in Hong Kong. The number of irregularly spaced boreholes ...
TL;DR: In this paper, the authors address the management of rockfall risk through baseline remote monitoring of susceptible slopes along a transportation corridor along the Fraser River valley in western Canada using a terrestrial laser scanner and supporting remote sensing technologies.
Abstract: Rockfalls represent significant risks to safe and efficient use of transportation corridors. In this paper, we address the management of rockfall risk through baseline remote monitoring of susceptible slopes (every 2–4 months) along a transportation corridor along the Fraser River valley in western Canada using a terrestrial laser scanner and supporting remote sensing technologies. This includes identifying potential rockfall source zones based on incipient signs of failure, tracking kinematics in three dimensions to better understand the mechanism of failure, estimating potential failure volumes based on bounding joint structure, and transmitting this information to the railway operator for an assessment of risk. We demonstrate our approach for one case along the line where we identified several potential failures ranging in volume from 48 to 4200 m3. Our projections of the location of failures were successful, in that volume projections were within 10%–55%, and the anticipated kinematics and failure mec...
TL;DR: In this paper, the authors investigated the compression and shear behavior of loosely compacted loess via two series of saturated and unsaturated direct shear tests and used the vapor transfer mechanism to modify a shear.
Abstract: Compression and shear behavior of a loosely compacted loess is investigated via two series of saturated and unsaturated direct shear tests. The vapor transfer mechanism is used to modify a shear bo...
TL;DR: The pullout resistance of reinforcement, such as geogrids in mechanically stabilized earth (MSE) walls, includes the skin friction between the soil and solid geogrid surfaces as mentioned in this paper.
Abstract: The pullout resistance of reinforcement, such as geogrids in mechanically stabilized earth (MSE) walls, includes the skin friction between the soil and solid geogrid surfaces. It also includes the ...
TL;DR: In this article, four geosynthetic clay liners serving as single liners were exhumed from below 0.7 m of silty sand on a 3:1 (horizontal:vertical) north-facing slope at the QUELTS site in Godfrey, Ontario.
Abstract: Four geosynthetic clay liners (GCLs) serving as single liners were exhumed from below 0.7 m of silty sand on a 3:1 (horizontal:vertical) north-facing slope at the QUELTS site in Godfrey, Ontario, a...
TL;DR: In this article, the stability of cut slopes is greatly influenced by seasonal pore-water pressure variations under the combined effect of rainfall and vegetation, and predicting soil-atmosphere interaction is difficult.
Abstract: The stability of cut slopes is greatly influenced by seasonal pore-water pressure variations under the combined effect of rainfall and vegetation. However, predicting soil–atmosphere interaction is...
TL;DR: Sinkholes induced by long-term internal erosion around defective sewer pipes have been widely reported as mentioned in this paper and there is a need for an efficient method to understand the influence of pipe defects on intern...
Abstract: Sinkholes induced by long-term internal erosion around defective sewer pipes have been widely reported. There is a need for an efficient method to understand the influence of pipe defects on intern...
TL;DR: Many of the world reserves of fossil fuels are located at various water depths in fine-grained sediment under the seabed, which contains relatively large biogas bubbles as discussed by the authors.
Abstract: Many of the world reserves of fossil fuels are located at various water depths in fine-grained sediment under the seabed. The fine-grained sediment contains relatively large biogas bubbles, which h...
TL;DR: In this paper, a generic database of seven parameters, including relative density and friction angle, for coarse-grained soils from 176 studies, covering a wide range of reconstituted and in s...
Abstract: This study compiles a generic database of seven parameters, including relative density and friction angle, for coarse-grained soils from 176 studies, covering a wide range of reconstituted and in s...
TL;DR: In this article, plant transpiration induces suction in the soil, but its effects on soil bioengineering using vegetation has been recognised as an environmentally friendly solution for shallow slope stabilization.
Abstract: Soil bioengineering using vegetation has been recognised as an environmentally friendly solution for shallow slope stabilization. Plant transpiration induces suction in the soil, but its effects on...
TL;DR: A landslide occurred on 10 May 2010, along the Salvail River, in the municipality of Saint-Jude, Quebec as mentioned in this paper, and the debris of the landslide was formed of clay having horst and graben shapes.
Abstract: A landslide occurred on 10 May 2010, along the Salvail River, in the municipality of Saint-Jude, Quebec. Debris of the landslide was formed of clay having horst and graben shapes, typical of spread...