Simulating the water content and temperature changes in an experimental embankment using meteorological data

： ： ： ： An experimental embankment was constructed in Rouen, France. The construction was completed in December 2004. The first objective of this experiment is to investigate the influence of climatic changes on the soil response such as changes in water content and temperature as well as the induced vertical and horizontal displacements; and the second objective is to investigate the soil response under water flooding from the base of embankment. In this study, the changes in temperature, volumetric water content and suction along the central axis have been analysed using a one-dimensional model and based on the meteorological data obtained in the field. Comparisons made between the measurements and simulations have shown the relevance of the method adopted, provided that suitable boundary conditions and soil parameters are taken into consideration. Moreover, both the simulation and field monitoring showed that climatic effects are limited to a shallow depth, which results from the low permeability of the compacted fill. Introduction Embankments are made up of unsaturated compacted soils. Their behaviour is strongly affected by the climatic or environmental perturbations. When climatic conditions change, the temperature, water content and suction of soils change. When clayey soils are involved, significant ground movement or soil cracking can occur, leading to possible damage to buildings and geotechnical constructions (Arbizzi et al. 2008, Borde et Despres 2008). Indeed, recent assessment on hazards caused by droughts showed that evapotranspiration is also an important process to be accounted for in natural hazards analysis. The evapotranspiration process has been widely studied in the field of meteorology and agronomy. Very often, the potential evapotranspiration (PET) is calculated to obtain a first estimate. The most common methods used for PET calculation are the Penman method, the Penman-Monteith method and the Turc method (see Guyot 1997 for a comprehensive review). The actual evapotranspiration (ET) can be determined by either field measurement based on water balance or energy balance, or numerical analysis using standard meteorological data. For the numerical analysis, Choudhury et al. (1986) and Xu and Qiu (1997) developed different models allowing the calculation of ET in the case of bare soils (without vegetation) or homogenous canopy (grass, crops etc.). For a given soil, when the evapotranspiration is calculated using the models mentioned above, the boundary condition in term of water flux is determined, and further coupled analysis using the finite difference method or finite element method can be performed in …