Compression-induced suction change in a compacted expansive clay

Tang, Anh Minh; Cui, Yu-Jun; Barnel, Nathalie

doi:10.1201/9780203884430.ch46

Cited by 8 publications

(4 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These authors attributed the mentioned changes to increase in the intraaggregate porosity caused by exchange of water between the inter-aggregate and intra-aggregate pores. Tang et al (2008) also observed this phenomenon characterised by a slight increase of soil suction after compaction. The effect of suction on G max was also evidenced in the present study as untreated specimens which have been compacted at lower water contents (higher suction) have higher G max .…”

Section: Discussionmentioning

confidence: 67%

Effects of the maximum soil aggregates size and cyclic wetting–drying on the stiffness of a lime-treated clayey soil

Tang¹,

Vu²,

Cui³

2011

Géotechnique

View full text Add to dashboard Cite

Lime treatment is a well-known technique to improve the mechanical response of clayey subgrades of road pavements or clayey soils used for embankment. Several studies show that lime treatment significantly modifies the physical and hydromechanical properties of compacted soils. Nevertheless, studies on the scale effect under climatic changes are scarce. Actually, wetting–drying cycles might significantly modify the microstructure of treated soils, giving rise to changes in hydromechanical properties. This modification could be dependent on the size of soil aggregates before lime treatment. In the present work, this scale effect was studied by investigating the stiffness of a compacted lime-treated clayey soil using bender elements. The studied soil was first air-dried and ground into a target maximum soil aggregates size (Dmax). For each aggregate size, the soil was humidified to reach the target water contents wi, then mixed with 3% of lime powder (mass of lime divided by mass of dried soil) prior to the static compaction at a dry density of 1·60 Mg/m3. Two initial water contents (wi = 14 and 18%) and four maximum soil aggregates sizes (Dmax = 0·4, 1·0, 2·0 and 5·0 mm) were considered. After the compaction, the soil specimen (50 mm in diameter and 50 mm high) was covered by plastic film in order to prevent soil moisture changes. The soil stiffness was then monitored at variable time intervals until reaching stabilisation. Afterwards, the soil specimen was subjected to full saturation followed by air-drying to come back to its initial water content. The results show that: (a) the soil stiffness after lime-treatment is significantly dependent on the aggregate size: the finer the aggregates the higher the soil stiffness; (b) the effect of initial water content on the stiffness is negligible; and (c) the wetting–drying cycles seem to slightly increase the soil stiffness in the case of lime-treated specimens and decrease the soil stiffness in the case of untreated specimens. Furthermore, when an intensive drying was applied reducing the soil water content lower than the initial level, the soil stiffness decreased drastically after the subsequent wetting.

show abstract

Section: Discussionmentioning

confidence: 67%

Effects of the maximum soil aggregates size and cyclic wetting–drying on the stiffness of a lime-treated clayey soil

Tang¹,

Vu²,

Cui³

2011

Géotechnique

View full text Add to dashboard Cite

show abstract

“…The extra BBM parameters that account for the expansive nature of MX80 bentonite are calibrated based on the provided experimental data and also listed in Table 4. The soil water retention data as given by [84,87,88] are fitted using the van Genuchten formula [23] À8 . The saturated liquid water hydraulic conductivity is estimated based on the data provided by [84] and the experimental data by [26].…”

Section: Finite Element Model and Materials Parametersmentioning

confidence: 99%

A study on how to couple thermo-hydro-mechanical behaviour of unsaturated soils: Physical equations, numerical implementation and examples

Abed

Sołowski

2017

Computers and Geotechnics

View full text Add to dashboard Cite

a b s t r a c tThis paper describes a thermo-hydro-mechanical framework suitable for modelling the behaviour of unsaturated soils. In particular, this paper focuses on bentonite clay subjected to a thermo-hydromechanical load, as in the case of nuclear waste engineering barriers. The paper gives a theoretical derivation of the full set of coupled balance equations governing the material behaviour as well as an extended physical interpretation. Finally, a finite element discretisation of the equations and number of simulations verifying their implementation into a custom finite element code is provided. Some aspects of the formulation are also validated against experimental data.

show abstract

“…17a. Compressing the soil under undrained condition will lead to some suction decrease [127,131], say to point B. Assume B is still inside the elastic zone.…”

Section: Water Retention Behaviour and Hydro-mechanical Couplingmentioning

confidence: 99%