K0 of sand measured by a plane-strain apparatus

2007 ◽  
Vol 44 (8) ◽  
pp. 1006-1012 ◽  
Author(s):  
Dariusz Wanatowski ◽  
Jian Chu
Keyword(s):  
Linear Relationship ◽  
Plane Strain ◽  
Void Ratio ◽  
Earth Pressure ◽  
Triaxial Tests ◽  
Preparation Methods ◽  
One Dimensional ◽  
Lateral Earth Pressure ◽  
Compression Behaviour ◽  
The One

Experimental results are presented in this note to study the coefficient of lateral earth pressure at rest, K0, of sand measured using a plane-strain apparatus. The data are also compared with the K0 measured by triaxial K0 consolidation tests. The test data show that the K0 values measured for specimens prepared using the water sedimentation method vary little with the void ratio of the soil, and therefore do not agree with the K0 values calculated using Jaky’s equation, which uses the peak friction angles obtained from either plane-strain or triaxial tests. The K0 values measured for specimens prepared using the moist tamping method follow a linear relationship with the void ratio. However, this relationship does not agree with Jaky’s equation either. The K0 values obtained from tests on the specimens prepared using the two different preparation methods are different, which may reflect the influence of soil fabrics or structures on the one-dimensional compression behaviour of soil.

Effect of particle fabric on the coefficient of lateral earth pressure observed during one-dimensional compression of sand

2013 ◽  
Vol 50 (5) ◽  
pp. 457-466 ◽  
Author(s):  
Sheri Northcutt ◽  
Dharma Wijewickreme
Keyword(s):  
Relative Density ◽  
Stress Measurement ◽  
Earth Pressure ◽  
Friction Angle ◽  
Fraser River ◽  
Initial Particle ◽  
River Sand ◽  
One Dimensional ◽  
Lateral Earth Pressure ◽  
The One

The effect of initial particle fabric on the one-dimensional compression response of Fraser River sand was investigated. One-dimensional compression with lateral stress measurement was carried out on reconstituted Fraser River sand specimens using an instrumented oedometer. Laboratory specimens were reconstituted by air pluviation, tamping, and vibration and were prepared with an initial relative density ranging from medium loose to very dense. For Fraser River sand in one-dimensional compression, air-pluviated specimens yielded the highest values for the coefficient of lateral earth pressure at rest (Ko), tamped specimens produced the lowest Ko values, and vibrated specimens produced intermediate Ko values. The results from the present study demonstrate that specimens resulting from different laboratory reconstitution methods (i.e., different initial particle fabrics) exhibit different one-dimensional compression responses and produce different Ko values. A “fabric factor” was introduced to account for the effect of the initial particle fabric on the measured coefficient of lateral earth pressure at rest. Using the fabric factor, the constant volume friction angle, and the specimen relative density, a new empirical equation defining the coefficient of lateral earth pressure at rest during normally consolidated loading is proposed.

scholarly journals Post-liquefaction reconsolidation of sand

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150745 ◽  
Author(s):  
O. Adamidis ◽  
G. S. P. Madabhushi
Keyword(s):  
Void Ratio ◽  
One Dimensional ◽  
Geotechnical Centrifuge ◽  
Significant Damage ◽  
Pore Water Pressures ◽  
The One ◽  
Crucial Parameter ◽  
Excess Pore ◽  
Good Agreement ◽  
Made In

Loosely packed sand that is saturated with water can liquefy during an earthquake, potentially causing significant damage. Once the shaking is over, the excess pore water pressures that developed during the earthquake gradually dissipate, while the surface of the soil settles, in a process called post-liquefaction reconsolidation. When examining reconsolidation, the soil is typically divided in liquefied and solidified parts, which are modelled separately. The aim of this paper is to show that this fragmentation is not necessary. By assuming that the hydraulic conductivity and the one-dimensional stiffness of liquefied sand have real, positive values, the equation of consolidation can be numerically solved throughout a reconsolidating layer. Predictions made in this manner show good agreement with geotechnical centrifuge experiments. It is shown that the variation of one-dimensional stiffness with effective stress and void ratio is the most crucial parameter in accurately capturing reconsolidation.

Predicting the properties of bentonite-sand mixtures

Clay Minerals ◽  
1996 ◽  
Vol 31 (2) ◽  
pp. 243-252 ◽  
Author(s):  
L. H. Mollins ◽  
D. I. Stewart ◽  
T. W. Cousens
Keyword(s):  
Hydraulic Conductivity ◽  
Linear Relationship ◽  
Void Ratio ◽  
Preparation Technique ◽  
Conductivity Data ◽  
Final State ◽  
Waste Containment ◽  
One Dimensional ◽  
Straight Line ◽  
Vertical Effective Stress

AbstractOne-dimensional swelling tests and hydraulic conductivity tests have been performed at vertical effective stresses up to 450 kPa on Na-bentonite powder and compacted sand/Na-bentonite mixtures (5, 10 and 20% bentonite by weight) to investigate the use of bentonite-improved soils for waste containment. It was found that bentonite powder swells to reach a final state described by a single straight line on a plot of void ratio against the logarithm of vertical effective stress, regardless of preparation technique. Swelling of sand/bentonite mixtures expressed in terms of the clay void ratio show a deviation from bentonite behaviour above a stress which depends on the bentonite content. Hydraulic conductivity data for bentonite and sand/bentonite mixtures indicate an approximately linear relationship between logarithm of hydraulic conductivity and logarithm of void ratio. A design model based on the clay void ratio, and the sand porosity and tortuosity is presented enabling the hydraulic conductivity of a mixture to be estimated.

Penetration and Removal of the Mooring Dolphin Platform With Three Caisson Foundations

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Puyang Zhang ◽  
Hongyan Ding ◽  
Conghuan Le
Keyword(s):  
Skin Friction ◽  
Strain Difference ◽  
Pressure Coefficient ◽  
Earth Pressure ◽  
Soil Disturbance ◽  
Triaxial Tests ◽  
Soil Pressure ◽  
Lateral Earth Pressure ◽  
Caisson Foundations ◽  
Factor Α

Mooring dolphin platforms (MDPs) with three caisson foundations were installed in the ice-drifting Bohai Sea of China. Before installation, prototype tests of penetration and removal processing were conducted near the design site. To determine the lateral soil pressure and skin friction of the caisson, soil pressure and strain gauge transducers were fixed along the external skirt of caisson B of MDP1. The shaft skin friction was calculated from the strain difference between any two points of the strain gauges. The transducer results indicated that when the soil property determined by unconsolidated and undrained (UU) triaxial tests was used to calculate the unit skin friction resistance, a value of the adhesion factor α of 1.5–2.0 is recommended. The factor α is 1–0.4 during the suction-assisted penetration phase. The lateral earth pressure coefficient K decreased with penetration depth, most likely due to seepage caused by underpressure. In addition, the difference between the measured values obtained from the soil pressure transducers represented the small tilt of MDP1 during the installation phase. The skin friction and lateral earth pressure significantly decreased in the removal phase, 12 h after the penetration phase, mainly due to the soil disturbance caused by suction penetration around the caisson.

scholarly journals Evolution of the coefficient of lateral earth pressure at rest with interparticle friction: a numerical study

2021 ◽  
Vol 249 ◽  
pp. 08015
Author(s):  
Hoang C Nguyen
Keyword(s):  
Discrete Element Method ◽  
Numerical Study ◽  
Earth Pressure ◽  
Normal Contact ◽  
Normal Contact Force ◽  
One Dimensional ◽  
Lateral Earth Pressure ◽  
Sample Density ◽  
Confining Pressures ◽  
Interparticle Friction

The grain-scale nature of evolution of the coefficient of lateral earth pressure at rest (K0) with interparticle friction (µp) is poorly understood. This study aims to use discrete element method simulations of vertical one-dimensional compression on both face centred cubic (FCC) samples and random monodisperse (RM) samples to link K0 and µp, and the results show that K0 increases with reductions in interparticle friction. Although K0 is dependent upon the sample density, patterns of evolutions with strain levels are likely to be unchanged with initial confining pressures. The stress-induced fabric becomes more anisotropic for samples with high values of the interparticle friction. The percentage of particles with a high value of the normal contact force increases with increasing strain levels as the interparticle friction increases in the simulations.

Lateral earth pressure at rest and compressibility of municipal solid waste

2000 ◽  
Vol 37 (6) ◽  
pp. 1157-1165 ◽  
Author(s):  
A O Landva ◽  
A J Valsangkar ◽  
S G Pelkey
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Laboratory Testing ◽  
Earth Pressure ◽  
Split Ring ◽  
One Dimensional ◽  
Large Size ◽  
Lateral Earth Pressure ◽  
Marine Clays ◽  
Compressibility Characteristics

The paper presents the results of laboratory testing of municipal solid waste samples subjected to one-dimensional compression with measurement of lateral stresses. The details of a large-size split-ring apparatus specially developed for this research are presented along with the data on earth pressure at rest and compressibility characteristics. The results show the influence of fibre content on the coefficient of earth pressure at rest in waste materials. The "delayed compression" behaviour observed in the laboratory is shown to be similar to the concepts developed by Bjerrum for normally consolidated sensitive marine clays. Issues such as validity of laboratory testing and sample-size effects are also discussed.Key words: earth pressure at rest, municipal solid waste, compressibility.

The one-dimensional consolidation of columns of soil of finite length

Soil Research ◽  
1969 ◽  
Vol 7 (3) ◽  
pp. 285 ◽  
Author(s):  
DE Smiles ◽  
HG Poulos
Keyword(s):  
Finite Length ◽  
Void Ratio ◽  
Water Movement ◽  
One Dimensional ◽  
Flow Parameters ◽  
The One

An analysis of the one-dimensional consolidation of a saturated column of soil of finite length is presented. This analysis, which is based on the theory of water movement in one-dimensional swelling systems, makes no assumptions of constancy with regard to variation of the flow parameters with variation in void ratio, and is not restricted in its application by the magnitude of the strains involved. An explanation of secondary consolidation is a consequence of the procedure.

Exploring the Multidimensional Facets of Authoritarianism: Authoritarian Aggression and Social Dominance Orientation

2008 ◽  
Vol 67 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Stefano Passini
Keyword(s):  
Social Dominance ◽  
Factor Model ◽  
Three Dimensional ◽  
Social Dominance Orientation ◽  
Model Fit ◽  
Regression Analyses ◽  
One Dimensional ◽  
Confirmatory Factor ◽  
The One ◽  
Better Than

The relation between authoritarianism and social dominance orientation was analyzed, with authoritarianism measured using a three-dimensional scale. The implicit multidimensional structure (authoritarian submission, conventionalism, authoritarian aggression) of Altemeyer’s (1981, 1988) conceptualization of authoritarianism is inconsistent with its one-dimensional methodological operationalization. The dimensionality of authoritarianism was investigated using confirmatory factor analysis in a sample of 713 university students. As hypothesized, the three-factor model fit the data significantly better than the one-factor model. Regression analyses revealed that only authoritarian aggression was related to social dominance orientation. That is, only intolerance of deviance was related to high social dominance, whereas submissiveness was not.

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