When a heat source such as a canister of radioactive waste is buried in a saturated soil the temperature changes that occur will cause the pore water to expand a greater amount than the voids of the soil. The temperature change will thus usually be accompanied by an increase in pore pressure. If the soil is sufficiently permeable these pore pressures will dissipate. This paper develops an analytic solution for the fundamental problem of a point heat source buried deep in a saturated soil.

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A solution is derived for the heat flow and consolidation which occur when a heat source is buried deep in a porous thermoelastic soil having anisotropic flow properties. This solution is used to examine the pore pressure generation and dissipation near both point and cylindrical heat sources. An increase in temperature will tend to generate an increase in excess pore pressure. However, the pore water will tend to flow from regions of high excess pore pressure to regions of low excess pore pressure, and so consolidation will occur, and temperature‐generated excess pore pressures will tend to dissipate. Many natural soils exhibit horizontal layering and so have a higher horizontal than vertical permeability. It is shown that in soils the excess pore pressure generated by a heat source is significantly less than that in an isotropic soil having an equal vertical permeability.

Britto (1984) presented a finite element formulation to analyse the coupled heat transfer–consolidation problem for a saturated fine-grained elastic soil. The formulation was validated by comparing it with analytical solutions for a soil layer heated on one side and a cylindrical heat source in an infinite medium. This Paper presents the results of the comparison of centrifuge test data and finite element analyses where the soil is treated as either purely elastic or elasto-plastic. In the centrifuge test, model heaters were pulled into clay layers and then heated. The induced temperature and pore pressure were measured until steady state conditions were reached. In the finite element analysis the model heaters were assumed to be in place at the beginning of the analysis. No account was taken of the disturbances caused by the heater being pulled into the soil. The temperatures and pore pressures generated due to the heating in normally consolidated clay were fairly well predicted using the modified Cam clay model of soil behaviour. Agreement was not as good when a Gibson type of elastic model was used. For an over-consolidated sample the pore pressures were under-predicted. Une formulation à éléments finis pour l'analyse du problème posé par la combinaison du transfert de chaleur avec la consolidation dans un sol élastique saturé de granulation fine fut déjá publiée (Britto, 1984). La formulation fut validée en la comparant avec des solutions analytiques pour une couche de sol réchauffée d'un côté et une source de chaleur cylindrique dans un milieu infini. Cet article présente les résultats d'une comparaison de données d'essais à centrifuge et d'analyses à éléments finis dans des cas où le sol est traité comme étant purement élastique ou élasto-plastique. Dans l'essai a centrifuge des réchauffeurs modèles furent introduits dans des couches d'argile et puis allumés. La température induite et la pression interstitielle étaient mesurées jusqu'à ce que des conditions stationnaires furent atteintes. Dans l'analyse à éléments finis on admettait que les réchauffeurs modèles se trouvaient en place au commencement de l'analyse, sans tenir compte de dérangements éventuels causés par l'introduction des réchauffeurs dans le sol. Le modèle modifié du comportement du sol basé sur l'argile de Cam prédirent assez bien les températures et les pressions interstitielles causées par le réchauffage dans une argile normalement consolidée. La concordance était inférieure lorsqu'un modèle élastique type Gibson fut employé. Dans le cas d'un échantillon sur-consolidé les pressions interstitielles furent sous-prédites.

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