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.

scholarly journals Experimental and Numerical Study of At-Rest Lateral Earth Pressure of Overconsolidated Sand

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Magdi El-Emam
Keyword(s):  
Numerical Model ◽  
Numerical Study ◽  
Retaining Wall ◽  
Earth Pressure ◽  
System A ◽  
Lateral Earth Pressure ◽  
Backfill Soil ◽  
Load Cells ◽  
Set Up ◽  
Wall System

The paper presents a one-meter-height rigid facing panel, supported rigidly at the top and bottom to simulate nonyielding retaining wall system. A set of load cells is used to measure the horizontal force at the top and bottom of the facing panel, which is converted to equivalent horizontal earth pressure acting at the back of the wall. Another set of load cells is used to measure the vertical load at the bottom of the wall facing, both at the toe and the heel. Uniformly graded sand was used as backfill soil. The measured wall responses were used to calibrate a numerical model that used to predict additional wall parameters. Results indicated that the measured horizontal earth force is about three times the value calculated by classical at-rest earth pressure theory. In addition, the location of the resultant earth force is located closer to 0.4 H, which is higher compared to the theoretical value of H/3. The numerical model developed was able to predict the earth pressure distribution over the wall height. Test set up, instrumentation, soil properties, different measured responses, and numerical model procedures and results are presented together with the implication of the current results to the practical work.

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.

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.

scholarly journals Evaluating the Role of Geofoam Properties in Reducing Lateral Loads on Retaining Walls: A Numerical Study

2021 ◽  
Vol 13 (9) ◽  
pp. 4754
Author(s):  
Muhammad Imran Khan ◽  
Mohamed A. Meguid
Keyword(s):  
Numerical Study ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Expanded Polystyrene ◽  
Wall Structure ◽  
Eps Geofoam ◽  
Lateral Earth Pressure ◽  
Backfill Soil

Expanded polystyrene (EPS) geofoam is a lightweight compressible material that has been widely used in various civil engineering projects. One interesting application of EPS in geotechnical engineering is to reduce the lateral earth pressure on rigid non-yielding retaining walls. The compressible nature of the EPS geofoam allows for the shear strength of the backfill soil to be mobilized, which leads to a reduction in lateral earth pressure acting on the wall. In this study, a finite element model is developed and used to investigate the role of geofoam inclusion between a rigid retaining wall and the backfill material on the earth pressure transferred to the wall structure. The developed model was first calibrated using experimental data. Then, a parametric study was conducted to investigate the effect of EPS geofoam density, relative thickness with respect to the wall height, and the frictional angle of backfill soil on the effectiveness of this technique in reducing lateral earth pressure. Results showed that low-density EPS geofoam inclusion provides the best performance, particularly when coupled with backfill of low friction angle. The proposed modeling approach has shown to be efficient in solving this class of problems and can be used to model similar soil-geofoam-structure interaction problems.

One-dimensional numerical study of compressible flow ejector

AIAA Journal ◽  
2002 ◽  
Vol 40 ◽  
pp. 1469-1472
Author(s):  
S. Han ◽  
J. Peddieson
Keyword(s):  
Compressible Flow ◽  
Numerical Study ◽  
One Dimensional

scholarly journals Numerical Modeling of the Interaction of Solitary Waves and Submerged Breakwaters with Sharp Vertical Edges Using One-Dimensional Beji & Nadaoka Extended Boussinesq Equations

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad H. Jabbari ◽  
Parviz Ghadimi ◽  
Ali Masoudi ◽  
Mohammad R. Baradaran
Keyword(s):  
Solitary Waves ◽  
Numerical Study ◽  
Time Integration ◽  
Boussinesq Equations ◽  
Linear Interpolation ◽  
Reflected Waves ◽  
One Dimensional ◽  
Propagating Waves ◽  
Linear Elements ◽  
Predictor Corrector

Using one-dimensional Beji & Nadaoka extended Boussinesq equation, a numerical study of solitary waves over submerged breakwaters has been conducted. Two different obstacles of rectangular as well as circular geometries over the seabed inside a channel have been considered in view of solitary waves passing by. Since these bars possess sharp vertical edges, they cannot directly be modeled by Boussinesq equations. Thus, sharply sloped lines over a short span have replaced the vertical sides, and the interactions of waves including reflection, transmission, and dispersion over the seabed with circular and rectangular shapes during the propagation have been investigated. In this numerical simulation, finite element scheme has been used for spatial discretization. Linear elements along with linear interpolation functions have been utilized for velocity components and the water surface elevation. For time integration, a fourth-order Adams-Bashforth-Moulton predictor-corrector method has been applied. Results indicate that neglecting the vertical edges and ignoring the vortex shedding would have minimal effect on the propagating waves and reflected waves with weak nonlinearity.

Lateral Earth Pressure Coefficient of Soils Subjected to Freeze–Thaw

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Xiaodong Zhao ◽  
Guoqing Zhou ◽  
Bo Wang ◽  
Wei Jiao ◽  
Jing Yu
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Saturated Soil ◽  
Frozen Soils ◽  
Freeze Thaw ◽  
Lateral Earth Pressure ◽  
Soil Deposits ◽  
Earth Pressure Coefficient ◽  
Water Saturated

Artificial frozen soils (AFS) have been used widely as temporary retaining walls in strata with soft and water-saturated soil deposits. After excavations, frozen soils thaw, and the lateral earth pressure penetrates through the soils subjected to freeze–thaw, and acts on man-made facilities. Therefore, it is important to investigate the lateral pressure (coefficient) responses of soils subjected to freeze–thaw to perform structure calculations and stability assessments of man-made facilities. A cubical testing apparatus was developed, and tests were performed on susceptible soils under conditions of freezing to a stable thermal gradient and then thawing with a uniform temperature (Fnonuni–Tuni). The experimental results indicated a lack of notable anisotropy for the maximum lateral preconsolidated pressures induced by the specimen’s compaction and freeze–thaw. However, the freeze–thaw led to a decrement of lateral earth pressure coefficient  K0, and  K0 decrement under the horizontal Fnonuni–Tuni was greater than that under the vertical Fnonuni–Tuni. The measured  K0 for normally consolidated and over-consolidated soil specimens exhibited anisotropic characteristics under the vertical Fnonuni–Tuni and horizontal Fnonuni–Tuni treatments. The anisotropies of  K0 under the horizontal Fnonuni–Tuni were greater than that under the vertical Fnonuni–Tuni, and the anisotropies were more noticeable in the unloading path than that in the loading path. These observations have potential significances to the economical and practical design of permanent retaining walls in soft and water-saturated soil deposits.

Sign in / Sign up

Export Citation Format

Share Document