Stress History-Dependent Deformation Characteristics of Dense Sand in Plane Strain

Flowslide or failure of loose granular soil slopes is often explained using liquefaction or instability data obtained from undrained triaxial tests. However, under static loading conditions, the assumption of an undrained condition is not realistic for sand, particularly clean sand. Case studies have indicated that instability of granular soil can occur under essentially drained conditions (e.g., the Wachusett Dam failure in 1907). Laboratory studies on Changi sand by Chu et al. in 2003 have shown that sand can become unstable under completely drained conditions. However, these studies were carried out under axisymmetric conditions and thus, cannot be applied directly to the analysis of slope failures. In this paper, experimental data obtained from plane-strain tests are presented to study the instability behaviour of loose and dense sand under plane-strain conditions. Based on these test data, the conditions for the occurrence of drained instability in plane strain are established. Using the modified state parameter, the conditions for instability under both axisymmetric and plane-strain conditions can be unified. A framework for interpreting the instability conditions of sandy slopes developed under axisymmetric conditions also extends into plane-strain conditions.

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Interpretation of cone penetration tests. Part I: Sand

Canadian Geotechnical Journal ◽

10.1139/t83-078 ◽

1983 ◽

Vol 20 (4) ◽

pp. 718-733 ◽

Cited By ~ 243

Author(s):

P. K. Robertson ◽

R. G. Campanella

Keyword(s):

Shear Strength ◽

Pore Pressure ◽

Cone Penetration Test ◽

Deformation Characteristics ◽

Penetration Test ◽

Cone Penetration ◽

Stress History ◽

Penetration Testing ◽

Cone Penetration Testing ◽

Recent Developments

Significant advances have been made in recent years in research, development, interpretation, and application of cone penetration testing. The addition of pore pressure measurements during cone penetration testing has added a new dimension to the interpretation of geotechnical parameters.The cone penetration test induces complex changes in stresses and strains around the cone tip. No one has yet developed a comprehensive theoretical solution to this problem. Hence, the cone penetration test provides indices which can be correlated to soil behaviour. Therefore, the interpretation of cone penetration data is made with empirical correlations to obtain required geotechnical parameters.This paper discusses the significant recent developments in cone penetration testing and presents a summarized work guide for practicing engineers for interpretation for soil classification, and parameters for drained conditions during the test such as relative density, drained shear strength, and deformation characteristics of sand. Factors that influence the interpretation are discussed and guidelines provided. The companion paper, Part II: Clay, considers undrained conditions during the test and summarizes recent developments to interpret parameters for clay soils, such as undrained shear strength, deformation characteristics of clay, stress history, consolidation characteristics, permeability, and pore pressure. The advantages and use of the piezometer cone are discussed as a separate topic in Part II: Clay. The authors' personal experiences and current recommendations are included. Keywords: static cone penetration testing, in situ, interpretation, shear strength, modulus, density, stress history, pore pressures.

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Analyses of Axisymmetric Upsetting and Plane-Strain Side-Pressing of Solid Cylinders by the Finite Element Method

Journal of Engineering for Industry ◽

10.1115/1.3427948 ◽

1971 ◽

Vol 93 (2) ◽

pp. 445-454 ◽

Cited By ~ 39

Author(s):

C. H. Lee ◽

Shiro Kobayashi

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Plastic Zone ◽

Plane Strain ◽

Deformation Characteristics ◽

Stress Distributions ◽

The Finite Element Method ◽

Percent Reduction ◽

Zone Development ◽

Element Method

Detailed studies of the deformation characteristics in axisymmetric upsetting and plane-strain side-pressing were attempted by the finite element method. Solutions were obtained up to a 33 percent reduction in height in axisymmetric upsetting and up to a 19 percent reduction in height in side-pressing, under conditions of complete sticking at the tool-workpiece interface. Load-displacement curves, plastic zone development, and strain and stress distributions were presented, and some of the computed solutions were compared with those found experimentally.

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INFLUENCE OF THE STRESS HISTORY ON THE DEFORMATION CHARACTERISTICS OF REMOULDED, NORMALLY CONSOLIDATED COHESIVE SOIL

Proceedings of the Japan Society of Civil Engineers ◽

10.2208/jscej1969.1981.316_97 ◽

1981 ◽

Vol 1981 (316) ◽

pp. 97-109

Author(s):

Seiki OHMAKI

Keyword(s):

Cohesive Soil ◽

Deformation Characteristics ◽

Stress History

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Finite element modeling of lateral pipeline–soil interactions in dense sand

Canadian Geotechnical Journal ◽

10.1139/cgj-2015-0171 ◽

2016 ◽

Vol 53 (3) ◽

pp. 490-504 ◽

Cited By ~ 28

Author(s):

Kshama Roy ◽

Bipul Hawlader ◽

Shawn Kenny ◽

Ian Moore

Keyword(s):

Finite Element ◽

Internal Friction ◽

Plane Strain ◽

Smooth Transition ◽

Burial Depth ◽

Angle Of Internal Friction ◽

Dense Sand ◽

Dilation Angle ◽

Wide Range ◽

Force Displacement

Finite element (FE) analyses of pipeline–soil interaction for pipelines buried in dense sand subjected to lateral ground displacements are presented in this paper. Analysis is performed — using the Arbitrary Lagrangian–Eulerian (ALE) method available in Abaqus/Explicit FE software — in the plane strain condition using the Mohr–Coulomb (MC) and modified Mohr–Coulomb (MMC) models. The MMC model considers a number of important features and properties of stress–strain and volume change behaviour of dense sand including the nonlinear pre- and post-peak behaviour with a smooth transition and the variation of the angle of internal friction and dilation angle with plastic shear strain, loading conditions (triaxial or plane strain), density, and mean effective stress. Comparing FE and experimental results, it is shown that the MMC model can better simulate the force–displacement response for a wide range of lateral displacements of the pipe for different burial depths, although the peak force on the pipe could be matched using the MC model. Examining the progressive development of zones of large inelastic shear deformation (shear bands), it is shown that the mobilized angle of internal friction and dilation angle vary along the length of the shear band; however, constant values are used in the MC model. A comprehensive parametric study is also performed to investigate the effects of pipeline diameter, burial depth, and soil properties. Many important aspects in the force–displacement curves and failure mechanisms are explained using the present FE analyses.

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Simulating the Response of Untrenched Flowlines due to Iceberg-Flowline-Soil Interaction

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics ◽

10.1115/omae2018-78128 ◽

2018 ◽

Cited By ~ 3

Author(s):

Kenton Pike ◽

Andrew Blundon

Keyword(s):

Constitutive Model ◽

Plane Strain ◽

Oil And Gas ◽

Penetration Resistance ◽

Element Analysis ◽

Dense Sand ◽

Grand Banks ◽

Vertical Loading ◽

Capacity Theory ◽

Definition Of

As offshore oil and gas fields mature on the Grand Banks, offshore Newfoundland and Labrador, marginal field subsea tie-backs are necessary to maintain production levels. Existing untrenched flowline lengths have been limited by the assumption that iceberg contact equates to flowline failure. However, extended tie-backs will be necessary to develop stranded resources. To potentially reduce the number of failure cases, we can consider a better definition of failure that accounts for the pipeline response due to iceberg-soil-pipeline interaction events. Reducing the failure rate from free-floating iceberg contacts alone can significantly increase safe tie-back lengths. This paper examines the flowline response from impacts with free-floating icebergs using large deformation finite element analysis. The plane strain pipe-soil interaction response is first simulated for pure vertical loading and compared against analytical bearing capacity theory. The influence of non-associativity in the soil constitutive model is demonstrated with respect to predicting the pipe drained penetration resistance in dense sands. Oblique vertical-horizontal plane strain pipe-soil interaction is also investigated, and it is shown that the vertical penetration resistance is reduced when the pipe trajectory deviates from pure vertical, consistent with published interaction diagrams. Lastly, the fully coupled interaction scenario of free-floating iceberg-pipe-soil interaction is simulated, showing the effects of the pipe wall thickness and soil strength. The numerical modelling procedures are described and the soil constitutive model that incorporates dense sand behavior is detailed.

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