Appareil triaxial pour l'étude du comportement thermique dé sols non saturés

1990 ◽  
Vol 27 (1) ◽  
pp. 119-128 ◽  
Author(s):  
C. Saix ◽  
P. Jouanna
Keyword(s):  
Key Words ◽  
Unsaturated Soils ◽  
Saturated Soils ◽  
Clayey Soils ◽  
Triaxial Apparatus ◽  
State Of Stress ◽  
Thermal Consolidation ◽  
Mechanical Consolidation ◽  
Sols Non Saturés

The thermal consolidation of unsaturated soils in a thermo-hydro-mechanical framework is studied in a thermal triaxial apparatus described in the paper. The results of the first tests performed, under a given state of stress, on both silty and clayey soils, show some similarities between purely thermal consolidation and mechanical consolidation on saturated soils. Key words: unsaturated soils, temperature, triaxial, consolidation. [Journal translation]

Éléments de couplage thermomécanique dans la consolidation de sols non saturés

2000 ◽  
Vol 37 (2) ◽  
pp. 308-317 ◽  
Author(s):  
C Saix ◽  
P Devillers ◽  
M S El Youssoufi
Keyword(s):  
Unsaturated Soils ◽  
Mechanical Characteristics ◽  
Experimental Results ◽  
Silty Sand ◽  
Characteristic Parameters ◽  
Mechanical Coupling ◽  
Thermal Consolidation ◽  
Quantitative Results ◽  
Mechanical Consolidation ◽  
Sols Non Saturés

Thermomechanical couplings in the consolidation of an unsaturated clayey silty sand are investigated. The couplings are analysed through the influence of the temperature (relative to the total vertical stress) on the mechanical characteristics (relative to thermal) of the consolidation. They are evidenced by means of two types of tests (thermal consolidation and mechanical consolidation). The two types of tests lead to quantitative results comparable with regards to characteristic parameters of both types of consolidation. Some elements of interpretation are proposed to integrate all of the experimental results within a framework of thinking resorting to the thermoelastoplastic behaviour of the soil under study and to the thermal and mechanical hardening phenomena.Key words: unsaturated soils, consolidation, thermal, mechanical, coupling, hardening.

Consolidation thermique par chaleur d'un sol non saturé

1991 ◽  
Vol 28 (1) ◽  
pp. 42-50 ◽  
Author(s):  
C. Saix
Keyword(s):  
Unsaturated Soil ◽  
Constitutive Law ◽  
Saturated Soils ◽  
Soil Consolidation ◽  
Thermal Compression ◽  
Triaxial Apparatus ◽  
Thermal Consolidation ◽  
Sol Non Saturé ◽  
Temperature Parameter ◽  
Definition Of

The thermal consolidation by heating of an unsaturated silty soil is studied by means of six tests performed in a thermal triaxial apparatus. The results show the importance of the temperature parameter and a clear similarity with the classical consolidation tests on saturated soils. A constitutive law is proposed for the thermal consolidation by heat that allows the definition of indices of thermal compression. This law is used to calculate the displacements in an unsaturated fill for heat storing. Key words: unsaturated soil, consolidation, heat, triaxial, modelling. [Translated by the Journal]

scholarly journals Study of primary creep behavior of clayey soils in landslide area : suction effect

2018 ◽  
Vol 149 ◽  
pp. 02027
Author(s):  
Dahhaoui Hachimi ◽  
Belayachi Naima ◽  
Zadjaoui Abdeldjalil
Keyword(s):  
Creep Behavior ◽  
Unsaturated Soils ◽  
Primary Creep ◽  
Creep Model ◽  
Clayey Soils ◽  
Landslide Area ◽  
Deviator Stress ◽  
Landslide Process ◽  
The University

Creep behavior of clayey soils plays an extremely important role in the landslide process. The soils that make up these sliding zones are often in unsaturated state. This point indicates the need to take into account the suction effect as hydric parameter on the long-term deformation of clayey soils. In this paper, a primary creep model named Modified Time Hardening (MTH) for unsaturated soils with different matric suction has been built. Based on the literature tests results[1][2], parameters C1 and C2 of the model have relations with suction and deviator stress level respectively. The primary creep strainwill be able to demonstrate unsaturated effect of the soils. comparison between the calculated results and the literature tests results shows a good coherence. The work underway at the university of Orleans will show later the relevance of model used in the present work.

Behavior of clayey soils on drying–wetting paths

1993 ◽  
Vol 30 (2) ◽  
pp. 287-296 ◽  
Author(s):  
Jean-Marie Fleureau ◽  
Siba Kheirbek-Saoud ◽  
Ria Soemitro ◽  
Said Taibi
Keyword(s):  
Experimental Research ◽  
Negative Pressure ◽  
Unsaturated Soils ◽  
Liquid Limit ◽  
The Other ◽  
Clayey Soils ◽  
Initial State ◽  
Stress Increase ◽  
Negative Pressures ◽  
Clayey Materials

Experimental research was carried out on 11 different clayey materials to determine the main characteristics of the drying and wetting paths and the influence of initial state and other factors. Normally consolidated paths are shown to have a large saturated domain, in which a negative pressure is equivalent to an isotropic stress increase; such paths can be derived from correlations with the liquid limit. On the other hand, the behavior of overconsolidated or dried samples is largely dependent on the range of stresses and negative pressures. Key words : suction, unsaturated soils, drying, wetting, correlations, models.

Aspects of the behaviour of compacted clayey soils on drying and wetting paths

2002 ◽  
Vol 39 (6) ◽  
pp. 1341-1357 ◽  
Author(s):  
Jean-Marie Fleureau ◽  
Jean-Claude Verbrugge ◽  
Pedro J Huergo ◽  
António Gomes Correia ◽  
Siba Kheirbek-Saoud
Keyword(s):  
Water Content ◽  
Pore Water ◽  
Unsaturated Soils ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Dry Density ◽  
Clayey Soils ◽  
Maximum Dry Density ◽  
Optimum Water Content ◽  
Optimum Water

A relatively large number of drying and wetting tests have been performed on clayey soils compacted at the standard or modified Proctor optimum water content and maximum density and compared with tests on normally consolidated or overconsolidated soils. The results show that drying and wetting paths on compacted soils are fairly linear and reversible in the void ratio or water content versus negative pore-water pressure planes. On the wet side of the optimum, the wetting paths are independent of the compaction water content and can be approached by compaction tests with measurement of the negative pore-water pressure. Correlations have been established between the liquid limit of the soils and such properties as the optimum water content and negative pore-water pressure, the maximum dry density, and the swelling or drying index. Although based on a limited number of tests, these correlations provide a fairly good basis to model the drying–wetting paths when all the necessary data are not available.Key words: compaction, unsaturated soils, clays, drying, wetting, Proctor conditions.

A new simple system for measuring volume changes in unsaturated soils

2002 ◽  
Vol 39 (3) ◽  
pp. 757-764 ◽  
Author(s):  
C W.W Ng ◽  
L T Zhan ◽  
Y J Cui
Keyword(s):  
Volume Change ◽  
Unsaturated Soils ◽  
Volumetric Strain ◽  
Apparent Volume ◽  
Differential Pressure ◽  
Simple System ◽  
Measuring System ◽  
Volume Changes ◽  
Ambient Temperatures ◽  
Triaxial Apparatus

A new simple system for accurately measuring overall total volume changes in unsaturated soil specimens with a triaxial apparatus is introduced in this paper. The basic principle of the measuring system is to record changes in the differential pressure due to changes in the water level inside an open-ended, bottle-shaped inner cell caused by volume change in the specimen and inside a reference tube using an accurate differential pressure transducer. Several important steps were taken to improve the accuracy and sensitivity of the measuring system. Detailed calibrations were carried out to account for apparent volume changes as a result of changes in cell pressure, fluctuation in the ambient temperatures, creep in the inner cell wall, and relative movement between the loading ram and the inner cell. The calibration results demonstrate that the measuring system is reasonably linear, reversible, and repeatable. The estimated accuracy of the measuring system is in the order of 32 mm3 (or 0.04% volumetric strain for a triaxial specimen 38 mm in diameter and 76 mm in height) once the system is properly calibrated.Key words: unsaturated soils, volume-change measurement, open-ended, bottle-shaped, inner cell, differential pressure, calibration.

A framework for the behaviour of unsaturated expansive clays

1992 ◽  
Vol 29 (6) ◽  
pp. 1013-1032 ◽  
Author(s):  
A. Gens ◽  
E. E. Alonso
Keyword(s):  
Key Words ◽  
Mechanical Behaviour ◽  
Unsaturated Soils ◽  
Expansive Soils ◽  
Experimental Results ◽  
Structural Rearrangements ◽  
Expansive Clays ◽  
Clay Model ◽  
Model Predictions ◽  
Low Activity

The paper presents a framework for describing the mechanical behaviour of unsaturated expansive clays. It is an extension of an existing formulation developed for unsaturated soils of low activity. The extended framework is based on the distinction within the material of a microstructural level where the basic swelling of the active minerals takes place and a macrostructural level responsible for major structural rearrangements. By adopting simple assumptions concerning the coupling between the two levels, it is possible to reproduce major features of the behaviour of unsaturated expansive clays. Some selected qualitative comparisons between model predictions and experimental results reported in the literature are presented. Despite the simplified hypotheses made, a very encouraging agreement is obtained. Key words : capillarity, clay, model, unsaturation, suction, expansive soils.

A Temperature Controlled Triaxial Apparatus for Testing Unsaturated Soils

2011 ◽  
Vol 34 (5) ◽  
pp. 103586
Author(s):  
L. D. Suits ◽  
T. C. Sheahan ◽  
Anuchit Uchaipichat ◽  
Nasser Khalili ◽  
Saman Zargarbashi
Keyword(s):  
Unsaturated Soils ◽  
Triaxial Apparatus ◽  
Temperature Controlled

Mini suction probe for matric suction measurements

2002 ◽  
Vol 39 (6) ◽  
pp. 1427-1432 ◽  
Author(s):  
Inge Meilani ◽  
Harianto Rahardjo ◽  
Eng-Choon Leong ◽  
Delwyn G Fredlund
Keyword(s):  
Pore Water ◽  
Unsaturated Soils ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Matric Suction ◽  
Lateral Direction ◽  
Triaxial Apparatus ◽  
Specimen Height ◽  
Pressure Changes ◽  
Accurate Reading

A modified triaxial apparatus with mini suction probes was fabricated to study the matric suction along the specimen height during unsaturated triaxial testing. Three mini suction probes were placed at 3/4, 1/2, and 1/4 height of the specimen, each at 120° apart in the lateral direction. This paper presents the development of the mini probe for matric suction measurements. Evaluation of the performance shows that the fabricated mini probe provides a rapid response and accurate reading under negative and positive pore-water pressure changes. Matric suctions as high as 400 kPa were successfully measured on soil specimens over a time span of 15 h. On the other hand, the mini suction probes were also found to be able to measure a matric suction of 200 kPa for a longer period of 155 h.Key words: matric suction, mini suction probe, triaxial, unsaturated soils, mid-height pore-water pressure measurement.

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