Evaporation, shrinkage and intrinsic permeability of unsaturated clayey soil: analytical modelling versus experimental d
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ICAGE 2016
Evaporation, shrinkage and intrinsic permeability of unsaturated clayey soil: analytical modelling versus experimental data Houcem Trabelsi 1,2 & Bilel Hadrich 3
&
Houda Guiras 1,4
Received: 13 April 2017 / Accepted: 27 March 2018 # Saudi Society for Geosciences 2018
Abstract This paper presents the experimental study conducted on a clayey soil originating from the region of Béja, north-west of Tunisia. The evaporation, shrinkage and permeability behaviours were studied. The Soil Water Retention Curve (SWRC) was determined from the slurry state to dry state, under the desiccation path (called initial drying curve). The Crack Intensity Factor (CIF), settlement and void ratio were also studied to characterise the shrinkage phenomenon during desiccation. Moisture content (ω), saturation degree (Sr) and evaporation rate (Re) evolutions during desiccation path were also presented. This type of slurry clay presents three stages during the desiccation process (pendular, funicular and capillary regimes). During desiccation process, the evaporation rate presents a linear relationship as a saturation degree function. Furthermore, the evaporation rate versus suction presents two phases: quasi-saturated and unsaturated states. This paper introduces a study of the hygroscopic and mechanical parameters naturally modified during a desiccation process and proposes some analytical models to describe clay behaviour. Using these parameters, we can determine the intrinsic permeability during the desiccation process. Keywords Clay . Evaporation . Desiccation . Shrinkage . Suction . Analytical modelling
Introduction Evaporation is an essential part of the water cycle. Water evaporation is established from saturated soil surface, in contact with air. In hydrology, evaporation is collectively termed evapotranspiration. Water evaporation occurs when the soil surface is exposed to a more or less dry environment, allowing water molecules to escape and form water vapour. In
This article is part of the Topical Collection on Georesources and Environmental Management * Bilel Hadrich [email protected] 1
National Engineering School of Tunis, Civil Engineering laboratory, University of Tunis EL Manar, B.P. 32, 1002-Le Belvédère, Tunis, Tunisia
2
National Engineering School of Sfax, University of Sfax, Sfax, Tunisia
3
National Engineering School of Sfax, Unité de Biotechnologie des Algues, University of Sfax, Sfax, Tunisia
4
Higher Institute of Technological Studies of Nabeul-ISET, Nabeul, Tunisia
geotechnical and environmental engineering, increasing attention has been paid to the coupled thermo-hydro-mechanical problems of clayey soils. This is partially due to the increased number of catastrophic landslide, induced by the degradation of soil strength triggered by humidification/desiccation cycles (Philip 1957; Or 1996; Tang et al. 2008; Trabelsi 2014). The dryness phenomenon causes a considerable damage to structures built on initially quasi-saturated soils. On one hand, the investigation of a water retention curve a
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