Modelling the Small Strain Behaviour of a Cemented Silty Sand with Bounding Plasticity

Soils have nonlinear stiffness and develops irrecoverable strains even at very small strain levels. Accurate modeling of stress-strain behaviour at various strain levels is very important for predicting the deformation of soils. Some existing stress-strain models are reviewed and evaluated firstly. And then a new simple non-linear stress-strain model is proposed. Four undetermined parameters involved in the proposed model can be obtained through maximum Young’s module, deformation module, and limit deviator stress and linearity index of soils that can be measured from experiment directly or calculated by empirical formulas indirectly. The effectiveness of the proposed stress-strain model is examined by predicting stress-strain curves measured in plane-strain compression test on Toyota sand and undrained triaxial compression test on London clay. The fitting results of the proposed model are in good agreement with experimental data, which verify the effectiveness of the model.

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Small-strain behaviour of cemented soils

Géotechnique ◽

10.1680/geot.9.p.100 ◽

2012 ◽

Vol 62 (10) ◽

pp. 943-947 ◽

Cited By ~ 22

Author(s):

J. TRHLíKOVá ◽

D. MAšíN ◽

J. BOHáč

Keyword(s):

Small Strain ◽

Strain Behaviour ◽

Cemented Soils

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Small Strain Behaviour and Viscous Effects on Sands and Sand-Clay Mixtures

Soil Stress-Strain Behavior: Measurement, Modeling and Analysis - Solid Mechanics and Its Applications ◽

10.1007/978-1-4020-6146-2_3 ◽

2007 ◽

pp. 159-190 ◽

Cited By ~ 5

Author(s):

H. Di Benedetto

Keyword(s):

Small Strain ◽

Viscous Effects ◽

Strain Behaviour

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Experimental Investigation on Small-Strain Stiffness of Marine Silty Sand

Journal of Marine Science and Engineering ◽

10.3390/jmse8050360 ◽

2020 ◽

Vol 8 (5) ◽

pp. 360 ◽

Cited By ~ 1

Author(s):

Qi Wu ◽

Qingrui Lu ◽

Qizhou Guo ◽

Kai Zhao ◽

Pen Chen ◽

...

Keyword(s):

Experimental Investigation ◽

Void Ratio ◽

Reduction Rate ◽

Confining Pressure ◽

Small Strain ◽

Silty Sand ◽

Bender Element ◽

Small Strain Stiffness ◽

Alternative State ◽

State Index

The significance of small-strain stiffness (Gmax) of saturated composite soils are still of great concern in practice, due to the complex influence of fines on soil fabric. This paper presents an experimental investigation conducted through comprehensive bender element tests on Gmax of marine silty sand. Special attention is paid to the influence of initial effective confining pressure ( σ c 0 ′ ), global void ratio (e) and fines content (FC) on Gmax of a marine silty sand. The results indicate that under otherwise similar conditions, Gmax decreases with decreasing e or FC, but decreases with increasing FC. In addition, the reduction rate of Gmax with e increasing is not sensitive to σ c 0 ′ , but obviously sensitive to changes in FC. The equivalent skeleton void ratio (e*) is introduced as an alternative state index for silty sand with various FC, based on the concept of binary packing material. Remarkably, the Hardin model is modified with the new state index e*, allowing unified characterization of Gmax values for silty sand with various FC, e, and σ c 0 ′ . Independent test data for different silty sand published in the literature calibrate the applicability of this proposed model.

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Laboratory study of small-strain behavior of a compacted silty sand

Canadian Geotechnical Journal ◽

10.1139/cgj-2012-0037 ◽

2013 ◽

Vol 50 (2) ◽

pp. 179-188 ◽

Cited By ~ 31

Author(s):

Ana Heitor ◽

Buddhima Indraratna ◽

Cholachat Rujikiatkamjorn

Keyword(s):

Moisture Content ◽

Structural Changes ◽

Initial Moisture Content ◽

Small Strain ◽

Matric Suction ◽

Point Of View ◽

Silty Sand ◽

Degree Of Saturation ◽

Compacted Soil ◽

Strain Behavior

Small-strain behavior is a key indicator for assessing the performance of compacted fills. Compaction conditions, i.e., initial moisture content and applied energy, govern compaction effectiveness and thus, the structure and matric suction of compacted soil. This paper presents an experimental study of the small-strain behavior of compacted silty sand prepared with different compaction conditions. Specimens with varying initial moisture contents and compaction energies were tested with bender elements to determine the small-strain shear modulus (G0), while the post-compaction matric suction was measured using the filter paper method and tensiometer. The experimental data suggest a pronounced relationship between G0 and the degree of saturation (Sr) of the as-compacted soil specimens. X-ray computed tomography (CT) scans were performed to examine structural changes of selected specimens upon compaction. The laboratory results are also examined in light of common end-product specifications, which show that it is beneficial to compact the soil slightly dry of optimum moisture content from the modulus point of view.

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Modelling the influence of stress–strain history on the initial shear stiffness of an unsaturated compacted silt

Canadian Geotechnical Journal ◽

10.1139/t06-130 ◽

2007 ◽

Vol 44 (4) ◽

pp. 463-472 ◽

Cited By ~ 12

Author(s):

Roberto Vassallo ◽

Claudio Mancuso ◽

Filippo Vinale

Keyword(s):

Unsaturated Soil ◽

Shear Stiffness ◽

Small Strain ◽

Complex Stress ◽

Strain History ◽

Strain Behaviour ◽

Observed Behaviour ◽

Suction History ◽

Simple Stress

This is the follow-up paper to Vassallo et al. (2007), which discussed the experimentally observed small-strain behaviour of an unsaturated compacted silt. The influence that suction and, more in general, mean net stress – suction history has on the initial shear stiffness was analysed and ascribed to the accumulation of irreversible volumetric strains. In this study, a model able to predict the observed behaviour is proposed, based on classical unsaturated soil volumetric hardening elastoplastic formulations. Starting from the interpretation of the results relative to simple stress paths, such as preliminary equalization and loading–unloading compression, the results of "complex" stress paths, such as those including drying–wetting cycles, have subsequently been modelled by introducing some additional parameters.Key words: unsaturated, compacted, small strain, stiffness, volumetric behaviour, stress history.

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