Frost Heave and Ice Lenses Formation in Freezing Soils

A generalized model for secondary frost heave in freezing fine-grained soils is presented and discussed. The cryostatic suction effect, which increases upward water permeation, ice-lens growth during freezing, and, as a consequence, the increase of soil heave, is considered to be the main mechanism of moisture transfer. We recognize the need to determine the distribution of the moisture within the frozen fringe by approximation of the experimental data for the equilibrium unfrozen water content. This distribution is the result of the complicated interaction between water, ice and the mineral skeleton during the freezing process. The generalization of the Clapeyron relation, which is used in the studies of other authors, estimates only the drop in initial freezing temperature and does not define the connection with the external temperature gradient ∆T, which is responsible for the frost heave process. This very important aspect is discussed in detail in the introduction to our paper. We take also into account the ratio Pe/Ste # 1 (where Pe<<1). This approach allows us to obtain a more general solution. The criterion of the ice lenses formation in fine-grained soils and the model for calculation of the lenses' thickness and spacing are derived. The dynamics of the lenses formation in histogram form is presented and discussed. The theoretical results obtained from the solution for fine-grained soils are compared in good agreement with experimental investigations. The model presented predicts the frost heave and ice lenses formation in freezing soils with reasonable accuracy, satisfactorily reflects observed phenomena, and thus can be suitable for engineering practice

Le trésor de Gardes-le-Pontaroux

Revue numismatique, 6e série, X, 1968, pp. 250-262. Albert Bronfenbrener, Le trésor de Gardes-le-Pontaroux. — II s'agit d'un trésor de 136 pièces découvert en 1967 en Charente. Il se compose de 114 monnaies royales françaises (de François I à Henri IV), de 7 seigneuriales et de 15 espagnoles. L'enfouissement provoqué probablement par les troubles de l'époque devrait être fixé entre 1593 et 1595. Une monnaie de Henri II de Navarre peut être considérée comme inédite. L'auteur s'est efforcé de dégager la valeur financière et économique de cet ensemble de monnaies.Bronfenbrener Albert. Le trésor de Gardes-le-Pontaroux. In: Revue numismatique, 6e série - Tome 10, année 1968 pp. 250-262

Le trésor de Guitinières

Bronfenbrener Albert. Le trésor de Guitinières. In: Revue numismatique, 6e série - Tome 11, année 1969 pp. 271-288

Frost Heave and Ice Lenses Formation in Freezing Soils

A generalized model for secondary frost heave in freezing fine-grained soils is presented and discussed. The cryostatic suction effect, which increases upward water permeation, ice-lens growth during freezing, and, as a consequence, the increase of soil heave, is considered to be the main mechanism of moisture transfer. We recognize the need to determine the distribution of the moisture within the frozen fringe by approximation of the experimental data for the equilibrium unfrozen water content. This distribution is the result of the complicated interaction between water, ice and the mineral skeleton during the freezing process. The generalization of the Clapeyron relation, which is used in the studies of other authors, estimates only the drop in initial freezing temperature and does not define the connection with the external temperature gradient ∆T, which is responsible for the frost heave process. This very important aspect is discussed in detail in the introduction to our paper. We take also into account the ratio Pe/Ste # 1 (where Pe<<1). This approach allows us to obtain a more general solution. The criterion of the ice lenses formation in fine-grained soils and the model for calculation of the lenses' thickness and spacing are derived. The dynamics of the lenses formation in histogram form is presented and discussed. The theoretical results obtained from the solution for fine-grained soils are compared in good agreement with experimental investigations. The model presented predicts the frost heave and ice lenses formation in freezing soils with reasonable accuracy, satisfactorily reflects observed phenomena, and thus can be suitable for engineering practice