This paper presents the findings of a laboratory investigation of the thermomechanical behaviour of clayey soils. The tests were performed on reconstituted and natural clayey soils using triaxial cells modified to control temperature. The range of temperatures that were investigated is from 20°to 60°C. The thermal behaviour of the clays and the influence of temperature on their mechanical behaviour were investigated separately. The analysis of the experimental results obtained in drained and undrained nonisothermal tests and during thermal consolidation made it possible to identify a link between the thermal and the time-dependent behaviour of the soil skeleton. Therefore, as for creep processes, the response of the soil to thermal loading is not unique but among other factors depends strongly on the overall and recent stress history experienced by the soil. In the range of temperatures investigated, the deformability and strength of the soil were found to be relatively independent of temperature. Stiffening of the soil results from thermal cycles.Résumé : Cet article présente les résultats d'une étude en laboratoire du comportement thermo-mécanique des sols argileux. Les essais ont été réalisés sur des sols argileux naturels et reconstitués dans des cellules triaxiales modifiées pour contrôler la température. La plage des températures qui ont été étudiées varie de 20°C à 60°C. Le comportement thermique des argiles et l'influence de la température sur leur comportement mécanique ont été étudiés séparément. L'analyse des résultats expérimentaux obtenus dans des essais non isothermiques drainés et non drainés, et durant la consolidation thermique, a permis d'identifier un lien entre les comportements du squelette du sol dépendant du temps et de la température. En conséquence, en ce qui concerne les processus de fluage, la réponse du sol au chargement thermique n'est pas unique, mais dépend fortement entre autres facteurs des histoires récente et complète des contraintes qu'a vécues le sol. L'on a trouvé que dans la plage des températures étudiées, la déformabilité et la résistance du sol sont relativement indépendantes de la température. La rigidité du sol est augmentée par les cycles thermiques.

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The behavior of a partially saturated soil during surface-water infiltration is analyzed by means of an elasto-plastic constitutive model formulated in terms of effective stress and extended to unsaturated conditions. The model is calibrated considering laboratory-scale experimental results under suction-controlled conditions. The wetting process in two collapsing soils, initially loaded at in situ stresses, is simulated by imposing two different boundary conditions: surface ponding and water flow. The stress paths resulting from the imbibition process are analyzed at different points inside the laye

An experimental study has been carried out to investigate the effects of soil partial saturation on the behaviour of laterally loaded piles. The proposed study has been conducted by means of centrifuge tests at 100×g, where a single vertical pile has been subjected to a combination of static horizontal load and bending moment. The study has been conducted on a silty soil characterized with laboratory testing under saturated and unsaturated conditions. During flight, two different positions of water table have been explored. The influence of density has been investigated compacting the sample with two different void ratio. Finally, the effects of a variation of saturation degree on the pile response under loading have been studied rising the water table to ground surface. Data interpretation allows drawing different considerations on the effects of partial saturation on the behaviour of laterally loaded piles. As expected, compared to saturated soils, partial saturation leads always to a stiffer and resistant response of the system. However, the depth of the maximum bending moment is related to the position of water table and the bounding effects induced by partial saturation appears to be more important for loose soils.

The representativeness of measurements monitored in earth dams is analysed to investigate how a given measured quantity can be used to interpret the dam's mechanical behaviour. Representativeness is evaluated on the basis of spatial continuity of the measured quantity and the sensitivity of that quantity to natural mechanical nonhomogeneity. The discussion is supported by results from case studies and numerical examples. The study is mainly focused on pore-water pressure measurements. Spatial continuity of pore-water pressure is analysed with consideration of both saturation and drainage conditions. The paper discusses how pore-water pressure representativeness can vary over the lifetime of the dam.Key words: earth dam, pore-water pressure, monitoring.