Soil freezing characteristics versus heat extraction rate

The processes that are operative during fine-grained soil freezing with no applied surcharge are described and related to the rate of net heat extraction. One-dimensional frost heave experiments were carried out on a Canadian silty soil under various freezing conditions. It was established that the segregational heave rate is strongly dependent on the rate of heat removal. No water flow was observed at heat extraction rates between 0.35 and 0.45 mW/mm[2]. Maximum segregational heave rates occurred at rates of about 0.1 mW/ mm[2]. For the same soil, however, significant variations in segregational heave rates were measured for a given heat removal rate during transient freezing. Frost heave predictions using freezing tests at rates of heat extraction representative of field conditions are also discussed.Les ph\ue9nom\ue8nes agissant lors du gel des sols fins non soumis \ue0 une surcharge sont d\ue9crits et reli\ue9s au taux d'extraction nette de chaleur. Des exp\ue9riences unidimensionnelles de soul\ue8vement d\ufb au gel ont \ue9t\ue9 faites au Canada sur un sol limoneux pour diff\ue9rentes conditions limites de temp\ue9rature. Il a \ue9t\ue9 \ue9tabli que le taux de soul\ue8vement d\ufb \ue0 la formation de lentilles de glace est fortement d\ue9pendant du taux d'extraction de la chaleur. Aucun \ue9coulement d'eau n'a \ue9t\ue9 observ\ue9 \ue0 des taux d'extraction situ\ue9s entre 0,35 et 0,45 mW/mm[2]. Les taux de soul\ue8vement s\ue9gr\ue9gationnel maximums sont survenus \ue0 environ 0,1 mW/mm[2]. Toutefois, pour le m\ueame sol, des variations importantes du soul\ue8vement s\ue9gr\ue9gationnel ont \ue9t\ue9 relev\ue9es pour un taux d'extraction de chaleur donn\ue9 au cours d'un gel transitoire. Les pr\ue9dictions du soul\ue8vement d\ufb au gel enregistr\ue9es lors d'essais effectu\ue9s \ue0 des taux d'extraction de chaleur repr\ue9sentatifs des conditions in situ sont \ue9galement examin\ue9es.Peer reviewed: YesNRC publication: Ye