scholarly journals Mechanical Properties of Granular Soils: Triaxial versus Plane Strain Investigations

2016 ◽  
Vol 63 (2-3) ◽  
pp. 135-156 ◽  
Author(s):  
Andrzej Sawicki ◽  
Justyna Sławińska ◽  
Jacek Mierczyński ◽  
Marcin Smyczyński
Keyword(s):  
Plane Strain ◽  
Soil Mechanics ◽  
Soil Parameters ◽  
Failure Behavior ◽  
Granular Soils ◽  
Tensor Algebra ◽  
True Triaxial ◽  
Triaxial Apparatus ◽  
Incremental Model ◽  
Versus Plane

AbstractThe paper compares the pre-failure behavior of granular soils investigated in the classical triaxial apparatus and in the true triaxial apparatus, under plane strain conditions. Both experiments are described within the framework of an incremental model of the pre-failure behavior of sands. The methods of tensor algebra are used to compare theoretical predictions with experimental results. The analysis presented deals with the pre-failure deformations of fully drained sand, as well as with its undrained behavior, including static liquefaction and the specific behavior of an initially dilative soil. Some key questions of soil mechanics are discussed, for instance, whether soil parameters determined from one configuration, such as triaxial conditions, can be applied in other cases.

scholarly journals Deformations and liquefaction of granular soils in plane strain conditions

2012 ◽  
Vol 59 (1-2) ◽  
pp. 13-35 ◽  
Author(s):  
Andrzej Sawicki ◽  
Justyna Sławińska
Keyword(s):  
Plane Strain ◽  
Numerical Algorithms ◽  
Complex Loading ◽  
Triaxial Tests ◽  
Granular Soils ◽  
Tensor Algebra ◽  
Initial State ◽  
Loading Paths ◽  
Incremental Model ◽  
Initial Anisotropy

Abstract An incremental model is proposed to describe pre-failure behaviour of granular soils in plane strain conditions. The model has been derived from an approach applied in the analysis of triaxial tests. We have applied the methods of tensor algebra to transfer our triaxial results to a 2D case. The model describes the pre-failure deformations of fully drained sands and phenomena associated with undrained response such as static liquefaction. This model has a simple structure in the form of incremental equations. For some simple loading paths, these equations can be integrated analytically. For more complex loading paths a simple numerical algorithms will be sufficient. The model takes into account an initial anisotropy of soil which is ignored in most models. It also takes into account the initial state of soil, defined as rather contractive or dilative, in addition to classical geotechnical division into loose and dense sands. The proposed constitutive equations allow the study of pre-failure instabilities of sand, and some examples are presented.We have also derived analytically the equation for an instability line.

An Apparatus for Plane Strain and True Triaxial Testing of Undisturbed Soil Samples

1973 ◽  
Vol 10 (3) ◽  
pp. 520-527 ◽  
Author(s):  
R. J. Mitchell
Keyword(s):  
Boundary Value Problems ◽  
Plane Strain ◽  
Soil Mechanics ◽  
Analytical Techniques ◽  
Soil Samples ◽  
Triaxial Testing ◽  
Stress Strain ◽  
Undisturbed Soil ◽  
True Triaxial ◽  
Undisturbed Samples

Extension of continuum analytical techniques to the solution of soil mechanics boundary value problems has created a need for more detailed information on the strength and stress–strain relations of soils. This note describes an apparatus that was developed to provide information on the plane strain and true triaxial behavior of undisturbed samples of soil.

Finite Element Modeling of a Mechanically Stabilized Earth Trial Wall

2021 ◽  
pp. 036119812110164
Author(s):  
Andrew Lees ◽  
Michael Dobie
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Retaining Wall ◽  
Back Analysis ◽  
Soil Parameters ◽  
Failure Behavior ◽  
Valuable Insight ◽  
Deformation And Failure ◽  
First Case ◽  
Soil Shear Strength

Polymer geogrid reinforced soil retaining walls have become commonplace, with routine design generally carried out by limiting equilibrium methods. Finite element analysis (FEA) is becoming more widely used to assess the likely deformation behavior of these structures, although in many cases such analyses over-predict deformation compared with monitored structures. Back-analysis of unit tests and instrumented walls improves the techniques and models used in FEA to represent the soil fill, reinforcement and composite behavior caused by the stabilization effect of the geogrid apertures on the soil particles. This composite behavior is most representatively modeled as enhanced soil shear strength. The back-analysis of two test cases provides valuable insight into the benefits of this approach. In the first case, a unit cell was set up such that one side could yield thereby reaching the active earth pressure state. Using FEA a test without geogrid was modeled to help establish appropriate soil parameters. These parameters were then used to back-analyze a test with geogrid present. Simply using the tensile properties of the geogrid over-predicted the yield pressure but using an enhanced soil shear strength gave a satisfactory comparison with the measured result. In the second case a trial retaining wall was back-analyzed to investigate both deformation and failure, the failure induced by cutting the geogrid after construction using heated wires. The closest fit to the actual deformation and failure behavior was provided by using enhanced fill shear strength.

scholarly journals A Study on Modelling the Plane Strain Behaviour of Sand and its Stability

2012 ◽  
Vol 59 (3-4) ◽  
pp. 85-100 ◽  
Author(s):  
Andrzej Sawicki ◽  
Justyna Sławinska
Keyword(s):  
Plane Strain ◽  
3D Model ◽  
Original Model ◽  
Governing Equations ◽  
Principal Stresses ◽  
Full System ◽  
Incremental Model ◽  
Strain Behaviour ◽  
Incremental Equations ◽  
Principal Strains

Abstract The plane strain behaviour of sand is studied using, previously proposed, incremental model describing its pre-failure deformations. Original model has been formulated for the tri-axial configuration, and then generalized for 3D conditions. This 3D model was subsequently adapted to study deformations of sand in the plane strain conditions, in the x1; x3 plane. There are three unknowns in such a configuration, namely the principal strains "1; "3 and the principal stress σ2. Respective equations were derived, and then applied to study deformations of sand for chosen stress paths. The governing incremental equations were integrated numerically, and it was shown, for some loading paths, that σ2 epends linearly on the other principal stresses, so introduction of apparent Poisson’s ratio is justified, as a kind of approximation. Subsequent analysis of deformations of sand was performed using this concept, as well as using full system of governing equations.

scholarly journals The Research on a Confined Modeling Method of the Effect of Deformable Ground Soil and Crawler Board

2018 ◽  
Vol 237 ◽  
pp. 02011
Author(s):  
LV Wei ◽  
Zhong-xin LI ◽  
LOU Peng
Keyword(s):  
Maximum Stress ◽  
Ground Deformation ◽  
Soil Mechanics ◽  
Soil Surface ◽  
Physical Significance ◽  
Soil Parameters ◽  
Soil Test ◽  
Analysis Model ◽  
Soil Pressure ◽  
Vehicle Mobility

There is a great relationship between the passing capacity of vehicles on the ground deformation road and the properties of confined and shear of ground soil, so it is necessary to establish a model that can reflect the soil pressure of the deformation. Physical significance of classic soil pressure experience parameters model is indeterminate, it was generally obtained by a lot of specific soil test. In this paper a new analysis model was built though introducing the maximum stress value of the crawler board and soil surface on basis of a kind of existing analysis model. This model reveals the relations among the confined characteristics of soil, soil parameters and the geometry of confined crawler board. These soil parameters can be obtained through the conventional soil mechanics test without a large number of specific soil test. Through the contrast experiment and predictions results, this model can effectively predict the sinkage of ground soil under the load, and provide a theory basis for the prediction of vehicle mobility.

A New True Triaxial Apparatus

Géotechnique ◽  
1969 ◽  
Vol 19 (2) ◽  
pp. 307-309 ◽  
Author(s):  
E. C. Hambly
Keyword(s):  
True Triaxial ◽  
Triaxial Apparatus ◽  
True Triaxial Apparatus
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