Movement and stability analysis of the Beaver Creek landslide, Saskatchewan, Canada

1985 ◽  
Vol 22 (3) ◽  
pp. 277-285 ◽  
Author(s):  
R. T. Yoshida ◽  
J. Krahn
Keyword(s):  
Stability Analysis ◽  
Key Words ◽  
Residual Strength ◽  
Case History ◽  
Single Unit ◽  
Slip Surface ◽  
Friction Angle ◽  
Slide Mass ◽  
History Of ◽  
Residual Values

This paper presents a case history of a multiblock landslide where the blocks move at varying rates along a common horizontal slip surface which follows the contact between stratified drift and underlying till. Movement measurements indicate that the blocks towards the toe move at a higher rate than blocks towards the scarp. Stability analyses show that the entire slide mass can be analyzed as a single unit as opposed to considering each block separately. This finding is compared with the analysis of other multiblock slides. The friction angle mobilized along the horizontal slip surface falls within the range of residual values measured in the laboratory. Key words: landslides, stability, analysis, translational slides, residual strength.

Application de la méthode de Bishop simplifiée aux remblais renforcés par les géosynthétiques

1993 ◽  
Vol 30 (5) ◽  
pp. 812-820 ◽  
Author(s):  
Abdelkader Houam ◽  
Jean Nuyens
Keyword(s):  
Tensile Strength ◽  
Stability Analysis ◽  
Key Words ◽  
Safety Factor ◽  
Slip Surface ◽  
New Approach ◽  
Analysis And Design ◽  
Reinforced Slopes ◽  
Bishop’S Method ◽  
Slope Safety

A new approach to stability analysis and design of geosynthetic reinforced slopes based on Bishop's method is presented. The effect of sheet inclination across the slip surface on the safety factor or on tensile strength of the sheet is materialized by the introduction, in the computation, of a factor varying from 0 to 1. The reason for this move is to take the flexibility of the sheet into account. Two tables of procedure were made up in case of analysis and design. Some examples are presented by way of illustrations. Key words : slope, safety, slip surface, slice, geosynthetics.

Thirteenth Bjerrum Memorial Lecture: A case history of mysterious settlements in a building

1992 ◽  
Vol 29 (1) ◽  
pp. 1-10
Author(s):  
J. M. Duncan
Keyword(s):  
Key Words ◽  
San Francisco ◽  
Case History ◽  
Memorial Lecture ◽  
Pile Driving ◽  
Technical Aspects ◽  
History Of ◽  
The One

This lecture describes the investigation of large and damaging settlements in the One Lombard Building in San Francisco Calif. The cause of the settlements was a mystery. Although it was known that settlement began during construction of a major new sewer near the building, it was not clear how the settlements could be related to the sewer construction activities. The paper explains the cause of the settlements and describes the technique used to remedy the problem. The legal and insurance aspects of the case, in some ways more mysterious than the technical aspects, are also described. Key words : settlement, foundations, clay, dewatering, pile driving, underpinning.

scholarly journals Formation of Clay-Rich Layers at The Slip Surface of Slope Instabilities: The Role of Groundwater

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2639
Author(s):  
Julia Castro ◽  
Maria P. Asta ◽  
Jorge P. Galve ◽  
José Miguel Azañón
Keyword(s):  
Clay Minerals ◽  
Slip Surface ◽  
Thick Layer ◽  
Friction Angle ◽  
High Plasticity ◽  
Slide Mass ◽  
Triggering Factor ◽  
Slope Instabilities ◽  
The Stability ◽  
Clay Layers

Some landslides around the world that have low-angle failure planes show exceptionally poor mechanical properties. In some cases, an extraordinarily pure clay layer has been detected on the rupture surface. In this work, a complex landslide, the so-called Diezma landslide, is investigated in a low- to moderate-relief region of Southeast Spain. In this landslide, movement was concentrated on several surfaces that developed on a centimeter-thick layer of smectite (montmorillonite-beidellite) clay-rich level. Since these clayey levels have a very low permeability, high plasticity, and low friction angle, they control the stability of the entire slide mass. Specifically, the triggering factor of this landslide seems to be linked to the infiltration of water from a karstic aquifer located in the head area. The circulation of water through old failure planes could have promoted the active hydrolysis of marly soils to produce new smectite clay minerals. Here, by using geophysical, mineralogical, and geochemical modelling methods, we reveal that the formation and dissolution of carbonates, sulfates, and clay minerals in the Diezma landslide could explain the elevated concentrations of highly plastic secondary clays in its slip surface. This study may help in the understanding of landslides that show secondary clay layers coinciding to their low-angle failure planes.

Preloading thick compressible subsoils: a case history

1995 ◽  
Vol 32 (3) ◽  
pp. 465-480
Author(s):  
Charles F. Ripley
Keyword(s):  
Key Words ◽  
Case History ◽  
Construction Control ◽  
History Of ◽  
Settlement Analysis ◽  
Settlement Behaviour

A case history of preloading and surcharging a more than 300 ft (1 ft = 0.3048 m) thick compressible subsoil is presented, with data on the settlement analysis, the fill design, other measures used for control of settlements, and the 24 year postconstruction performance. The essential factors for successful application of preloading to thick compressible subsoils are discussed. Key words : preloading, settlement analysis, construction control, settlement behaviour.

Stability analysis of two-dimensional excavated slopes considering strength anisotropy

2002 ◽  
Vol 39 (5) ◽  
pp. 1026-1038 ◽  
Author(s):  
Jeaan Hwang ◽  
Mandar Dewoolkar ◽  
Hon-Yim Ko
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stability Analysis ◽  
Slope Stability ◽  
Slip Surface ◽  
Slope Angle ◽  
Friction Angle ◽  
Strength Anisotropy ◽  
Extension Zone ◽  
Element Method

Using the finite element method, a cohesive horizontal ground is sequentially excavated until the stress state along a potential slip surface of the excavated slope reaches the critical state. Mobilized friction angle and stress ratio contours in the slope generated by the finite element solution are examined to quantify the part of the slip surface that undergoes extension resulting in anisotropic conditions. The effects of factors such as excavation depths, drainage boundary conditions, slope angles, and initial stress conditions on slope stability are investigated. It is shown that excavated slopes display anisotropic behavior and that the consideration of strength anisotropy in slope stability analysis is essential. For the example considered, it was found that the extent of the extension zone of the slip surface increases as the slope angle decreases and that this relationship is linear.Key words: slope stability, strength anisotropy, finite element method, limiting equilibrium.

Strength Anisotropy of a Tailings Sand and its Effect on Stability of a Tailing Dam

2011 ◽  
Vol 261-263 ◽  
pp. 1719-1723
Author(s):  
Rui Chen ◽  
Zai Hong Li ◽  
Wei Dong Lei ◽  
Wen Bin Luo
Keyword(s):  
Shear Strength ◽  
Stability Analysis ◽  
Slip Surface ◽  
Friction Angle ◽  
Engineering Practice ◽  
Shear Direction ◽  
Tailings Dam ◽  
Strength Anisotropy ◽  
Tailings Sand ◽  
Current Engineering

In current engineering practice, the effect of strength anisotropy on stability analysis of tailings dam is often ignored. This paper presents direct shear test results on a tailing sand with different angles between shear direction and bedding plane. It is found that shear strength of this soil is significantly directional dependent. The variations in peak friction angle are about 11o, which is approximately 28.3% of the minimum value. The effect of strength anisotropy on stability of a tailings dam is also investigated. The analysis considering anisotropic strength shows a smaller factor of safety and shallower most critical slip surface as compared with isotropic strength model that is used in current engineering practice. To achieve more accurate stability analysis of tailings dams, it is suggested to take into account shear strength anisotropy of tailings soils.

scholarly journals The ecology of herd immunity

2021 ◽  
Vol 50 (2) ◽  
pp. 79-85
Author(s):  
Fernando Dias de Avila-Pires
Keyword(s):  
Key Words ◽  
Case History ◽  
Herd Immunity ◽  
Sleeping Sickness ◽  
Short History ◽  
Herd Effect ◽  
History Of ◽  
The Subject ◽  
Recurrent Theme

The COVID-19 pandemic that began in early 2020 is currently the subject of thousands of articles on the various aspects of its epidemiology. One recurrent theme is the phenomenon of herd immunity or herd effect. In this article, I present a short history of the concept, the arguments around its nomenclature, and the ecologist’s view of the herd effect, using the case history of the sleeping sickness control in Africa. KEY WORDS: Herd immunity; convergence; ecology; sleeping sickness.

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