Análisis thm de la interacción suelo-atmósfera en suelos arcillosos sometidos a desecación
- Autores: Agustín Cuadrado Cabello
- Directores de la Tesis: Alberto Ledesma Villalba (dir. tes.), Pere Prat Catalan (dir. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2019
- Idioma: español
- Tribunal Calificador de la Tesis: Fernando Pardo de Santayana Carrillo (presid.), Sebastià Olivella Pastallé (secret.), Vicente Navarro Gamir (voc.)
- Programa de doctorado: Programa de Doctorado en Ingeniería del Terreno por la Universidad Politécnica de Catalunya
- Materias:
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- Resumen
Coupled processes between the soil and the atmosphere control soil water evaporation in its first stage, which leads to soil shrinkage and cracking by drying. However, soil-atmosphere interaction has received little attention from the Soil Mechanics point of view. Therefore, the objective of this thesis is to simulate drying processes in soils with a boundary condition which reproduces the atmosphere behaviour.
The interaction model used in the investigation is based on the surface energy balance equation. A summary of the main atmospheric phenomena involved is presented.
In order to understand the soil response under atmospheric variables, TH sinthetic drying simulations have been calculated by changing wind, radiation and air temperature. The models used are HYDRUS-1D and CODE_BRIGHT, which yield similar results. In addition to radiation, wind is shown to be an efficient surface drying system because of turbulent diffusion. The evaporative demand of the air determines the response of the soil, mainly trough relative permeability, which controls the water supply to the surface.
THM simulations of desiccating very fluid soil samples have been carried out as well. In all cases, the applied method reproduces well the experimental measures. The method consists in increasing the diffusion and replicates the self-weight consolidation. The former one extends the constant rate of evaporation, and the second one explains the soil saturation during the first days.
The simulations present two novel aspects. In one hand, one sim ulation reproduces a laboratoy drying test with a perimeter crack. The results show that evaporation through the crack is negligible. On the other hand, a simulation of a drying test in real conditions has been performed by applying flows as a boundary condition obtained from a decoupled meteorological model. Although the results have not been as expected, new future lines of research are open.
Finally, evaporation test results performed to check wether relative evaporation may be greater than one are shown. The results are not conclusive, but the wind and their angle of incidence invite to future tests to elucidate whether this is the reason why relative evaporation from soils is greater than that of free water.
