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Influence of freeze-thaw processes on soil rheological propertiesтезисы доклада
- Авторы: Romanenko K., Khaydapova D., Yudina A., Skvortsova E.
- Сборник: International Conference «Earth's Cryosphere: Past, Present and Future» (June 4-8, 2017, Pushchino, Russia). Program and conference materials
- Тезисы
- Год издания: 2017
- Первая страница: 125
- Последняя страница: 126
- Аннотация: The mechanism of cryogenic structure formation of soils, as the processes of swelling and shrinkage, is very interesting. The study of the processes of freezing and thawing, as well as swelling and shrinkage, will provide a deeper understanding of the nature of the formation of soil structures. The results of the research can find application in predicting the behavior of soils in conditions of changing climate. The aim of the study was to elucidate the effect of freeze-thaw processes on the rheological properties of Albiluvisol soil in the Moscow region under the conditions of a model experiment. The investigations were carried out on forest Albiluvisol heavy loam soil of the Moscow Region. Samples of soil were capillary moistened and frozen in the freezer for 30 minutes, then thawed at room temperature for 30 minutes. The temperature was detected by temperature sensors. Samples of the soil were subjected to 5 cycles of freezing-thawing. Further were determined granulometric and microaggregate composition and the rheological properties: the linear viscoelasticity range (the point of transition of the body condition from the elastic to the viscoelastic) and the point of intersection of the elasticity and viscosity moduli (the point of transition of the body condition from viscous-elastic to viscous) Changes of rheological properties as a result of multiple freezing-thawing were monitored: the range of linear viscoelasticity or the area of elastic behavior increases, but on the whole the range of elastic-ductile behavior decreases, it means that the soil behavior becomes more fragile and the structure breaks down and passes into a viscous flow condition . This can be explained by the destruction of soil aggregates as a result of crystallization of ice in the soil material, which is confirmed by the data of the microaggregate composition of the initial and after freeze-thaw cycles samples, which showed a decrease of the amount of large aggregated particles and an increase in the finely dispersed fraction in the samples after freezing. But the value of elasticity moduli and viscosity at the crossover point increases in the samples after freezing-thawing, which may indicate that small particles form bonds with each other and deform as a single system, and no slip boundaries are formed inside the deformed body. This indicates that multiple freezing-thawing without application of external pressure does not lead to the formation of a cryogenic structure typical of freezing soils, but contributes to the formation of a massive fusion structure. The research carried out with the support of RFBR grand № 16-04-01111
- Добавил в систему: Романенко Константин Александрович