scholarly journals Confidence and Accuracy in Determination of the Critical State Friction Angle

2009 ◽  
Vol 49 (3) ◽  
pp. 391-395 ◽  
Author(s):  
Mohsen Ghafghazi ◽  
Dawn Shuttle
Keyword(s):  
Critical State ◽  
Friction Angle

scholarly journals Field and Laboratory-based Approach for the Determination of Friction Angle of Geological Discontinuities of Malaysian Granites

2011 ◽  
Vol 28 (2) ◽  
pp. 151 ◽  
Author(s):  
R. A Ghani ◽  
T. L Goh ◽  
A. M Hariri ◽  
Y. N Baizura
Keyword(s):  
Friction Angle ◽  
Roughness Coefficient ◽  
Average Value ◽  
Peak Friction Angle ◽  
Maximum Value ◽  
Wide Range ◽  
Discontinuity Surfaces ◽  
Geological Discontinuities ◽  
Range Of Values

The basic friction angle, Φb for artificially sawn discontinuity planes for fresh granite, as determined by tilt testing, has an average value of 30º. For the natural rough discontinuity surfaces, a wide range of values have been determined for the peak friction angle, Φpeak ranging from 47º to a maximum value of 80º, depending on the joint roughness coefficient (JRC). The average values of the friction angles for the different degrees of roughness were as follows: JRC 2–4 = 58°; JRC 6–8 = 60°; JRC 8–10 = 47°; JRC 12–14 = 60°; JRC 14–16 = 71° ; JRC 18–20 = 80°.

scholarly journals Determination of Equivalent Mohr-Coulomb Criterion from Generalised Hoek-Brown Criterion

2021 ◽  
Author(s):  
Qingqing Yang ◽  
Fei Cai
Keyword(s):  
Principal Stress ◽  
Least Squares Method ◽  
Method Comparison ◽  
Friction Angle ◽  
Engineering Practice ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Coulomb Criterion ◽  
Minor Principal Stress

Abstract A new analytical solution is presented for determining equivalent Mohr-Coulomb (MC) shear strength parameters over an arbitrary interval of minor principal stress σ3 from the generalised Hoek-Brown (HB) criterion using least squares method. Comparison with several published examples demonstrates that the proposed solution had a capacity to accurately determine equivalent MC parameters over a given interval of σ3, as well as instantaneous MC parameters by using a very small interval of σ3. EMC parameters depended heavily on the interval of σ3, which highlighted the importance of intervals of σ3. A calculation case shows that the equivalent internal friction angle and cohesion over the interval of σ3 from tension cut-off σcut−off to maximum minor principal stress σ3max were approximately 12% smaller and 10.3% larger than those over an interval from tensile strength to σ3max, respectively. The proposed solution offers great flexibility for the application of the HB criterion with existing methods based on the MC criterion for rock engineering practice.

Ecological Highway Slope Stability Analysis by Inversion Method

2011 ◽  
Vol 250-253 ◽  
pp. 2161-2166
Author(s):  
Jun Zhao Gao ◽  
Guo Feng Xiao ◽  
Hai Qiang Miao
Keyword(s):  
Slope Stability ◽  
Soil Mechanics ◽  
Friction Angle ◽  
Inversion Method ◽  
Time Inversion ◽  
Long Time ◽  
Main Factors ◽  
Reinforcement Design ◽  
Rock And Soil

Side slop losing stability is one of the main factors which greatly influences freeway expedite construction, especially after side slop losing stability the determination of rock and soil mechanics parameter may take a long time. Inversion method to analyze slope stability can preferably solve the problem. During the treatment of the ecological freeway landslide, we can not obtain important Parameters due to great disparity of sample Parameters of landslide. However, using inversion method to get cohesion and internal friction Angle, and anglicizing its sensitivity during calculation of stability can identify reliable Parameters. According to slope stability calculus, the ecological reinforcement design scheme come into effect.

scholarly journals Landslide susceptibility on selected slopes in Dzanani, Limpopo Province, South Africa

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Makia L. Diko ◽  
Shallati C. Banyini ◽  
Batobeleng F. Monareng
Keyword(s):  
Landslide Susceptibility ◽  
Critical State ◽  
Anthropogenic Activities ◽  
Limpopo Province ◽  
Silty Clay ◽  
Clay Loam ◽  
Landslide Occurrence ◽  
Landslide Event ◽  
Physical Attributes

Inherent soil properties and anthropogenic activities on slope faces are considered potential recipes for landslide occurrence. The objectives of this study were to physically characterise unconsolidated soils and identify on-going anthropogenic activities on selected slopes in Dzanani in order to appraise their role as contributory factors in enhancing landslide susceptibility. Methods employed for this study comprised mapping, description of soil profile, identification of anthropogenic activities, as well as experimental determination of soil colour, particle size distribution and Atterberg limits. Geologically, the study area comprised rocks of the Fundudzi, Sibasa and Tshifhefhe Formations, ascribed to the Soutpansberg Group. Digging of foundations for construction purposes and subsistence agriculture were identified as the main anthropogenic activities. The soils were predominantly reddish-yellow in colour, texturally variable (silty clay – clayey – silty clay loam and clay loam) and of medium plasticity. Compared to soils from other parts of the world developed on volcanic cones or associated with a landslide event, those from Dzanani were qualified as generally inactive and not prone to landslides. Although the physical attributes suggested the soils were not at a critical state, on-going anthropogenic activities may enhance deep weathering and ultimately alter current soil physical characteristics to a critical state.

Determination of the friction angle of soils in triaxial-compression apparatus and shear devices

1985 ◽  
Vol 22 (3) ◽  
pp. 105-111
Author(s):  
A. L. Kryzhanovskii ◽  
Yu. S. Vil'gel'm ◽  
S. V. Medvedev
Keyword(s):  
Triaxial Compression ◽  
Friction Angle

scholarly journals The influence of organic polymer on properties of mineral concentrates

2013 ◽  
Vol 20 (2) ◽  
pp. 90-93
Author(s):  
Marzenna Popek
Keyword(s):  
High Risk ◽  
Internal Friction ◽  
Moisture Content ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Organic Polymer ◽  
Biodegradable Materials

AbstractTransport of mineral concentrates is associated with high risk of liquefaction of the cargoes. This type of goods containing water may liquefy and shift dangerously across the cargo compartments. Therefore, it is rational to limit the moisture content of the cargoes which may liquefy. To prevent sliding and shifting of ore concentrates in storage biodegradable materials composed of starch are added to the mineral concentrates. The influence of adding starch materials to the mineral concentrates on its parameters determining ability for safe shipment was assessed on the basis of determination of the following parameters: permeability, cohesion and internal friction angle of concentrates.

scholarly journals Deslizamento em Uma Vertente do Rio Madeira em Porto Velho – RO: Uma Análise Morfomecânica

2019 ◽  
Vol 12 (5) ◽  
pp. 1980
Author(s):  
Salem Leandro Moura dos Santos ◽  
Eliomar Pereira da Silva Filho ◽  
Isabel Leonor Iza Echeverria Herrera
Keyword(s):  
Mass Movement ◽  
Friction Angle ◽  
Piezometric Level ◽  
Convex Shape ◽  
Geomechanical Properties ◽  
Equilibrium Limit ◽  
Madeira River ◽  
Porto Velho ◽  
Superficial Erosion

Este estudo tem o objetivo de estabelecer o nível piezométrico que a vertente tinha antes do deslizamento, a morfometria e a causa do movimento de massa. Para isto, foi utilizada equação de Equilíbrio-Limite, com o Fator de segurança em 1,49 para estabelecer o nível piezométrico necessário para causar o colapso da encosta, como também, a determinação de propriedades geomecânicas, como coesão, densidade, ângulo de atrito, tensão de cisalhamento, limites de Atterberg, além da granulometria e da morfometria. A vertente apresentava o formato convexo no topo e côncavo na base, ambos seccionados no meio pelos formatos retilíneo e côncavo. A inclinação média era de 35,17° em uma dimensão de 46,01m. A Equação indicou um nível piezométrico mínimo de 18,53 metros de altura para o colapso. Um aspecto que influenciou o deslizamento foi à erosão superficial causada por uma galeria de água pluvial, que uma vez rompida, erodiu o pacote de material superficial, Argilo Siltoso Mosqueado, que serve de proteção para a vertente, pois possui maior coesão e plasticidade. Após a completa erosão do pacote superior, houve a exposição pontual do pacote inferior, que após sofrer forte precipitação pluvial de 32,20 mm, ocorrida no dia 30/09/2013, ocasionou a elevação do nível piezométrico deste material inferior, Silto Arenoso Tangencial, de menor coesão e plasticidade que saturou, comportando-se de maneira semi-líquida. Devido este material ser todo o alicerce da encosta, o seu colapso causou todo o deslizamento rotacional da vertente. Verifica-se a importância de manter o material superior desta margem do Rio  Landslide in The Madeira River Slope in Porto Velho - RO: A Morfomechanical analysis ABSTRACTThe aims this paper is establish the piezometric level that the slope had before sliding, morphometry and the cause of mass movement. For this, the Equilibrium-Limit equation was used, with the Safety Factor at 1.49 to establish the piezometric level necessary for collapse of the slope, as well as the determination of geomechanical properties, such as cohesion, density, friction angle , shear stress, Atterberg boundaries, granulometry and morphometry. The strand had the convex shape at the top and concave at the base, both sectioned in the middle by the rectilinear and concave shapes. The average slope was 35.17° in a dimension of 46.01m. Equation indicated a minimum piezometric level of18.53 metershigh for collapse. One aspect that influenced the sliding was the superficial erosion caused by a gallery of rainwater, which once ruptured, eroded the package of surface material, Silt Clay Mottled, which serves as protection for the slope, as it has greater cohesion and plasticity. After complete erosion of the upper package, there was a punctual exposition of the lower package, which after suffering heavy rainfall of32.20 mm, occurred on 09/30/2013, caused the elevation of the piezometric level of this lower material, Sand Silt Tangential, of lower cohesion and plasticity that saturated, behaving in a semi-liquid way. Because this material is the whole foundation of the slope, its collapse caused all the rotational slip of the slope. It’s important to maintain the superior material of the slope, aiming at the reduction of shear forces and erosions.Keywords: Piezometric Level, morphometry, Break Circle.

scholarly journals Numerical Experiments on Triaxial Compression Strength of Soil-Rock Mixture

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Yanxi Zhao ◽  
Zhongxian Liu
Keyword(s):  
Shear Strength ◽  
Triaxial Compression ◽  
Strain Curve ◽  
Friction Angle ◽  
Mechanical Parameters ◽  
Test Results ◽  
Data Statistics ◽  
Nonlinear Hardening ◽  
Properties Of Soil

Soil-rock mixture is a kind of unfavorable geologic material, and it is composed of low-strength soil particles and high-stiffness rock blocks. Mechanical properties of soil-rock mixture were controlled by the internal mesoscopic medium, thus resulting in great difficulties of determination of mechanical parameters. In this paper, influences of rock content, mesoscopic features, and random distribution of mixture in soil-rock mixture on its shear strength were discussed through discrete element numerical simulation of the laboratory triaxial test. Results demonstrated that, with the increase of rock content, the internal friction angle of soil-rock mixture increased continuously, while the cohesion of soil-rock mixture decreased firstly and then increased. The stress-strain curve belonged to a nonlinear hardening type, which was close to soil characteristic. However, the shear strength was affected by mesoscopic medium of mixture particles significantly, resulting in the strong discreteness of strength, and only by large amounts of data statistics can we get a better regularity of strength. The research results can provide references to determine mechanical parameters of soil-rock mixture.

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