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  • Effect of freezing and thawing processes on soil aggregate stability
  • Erodibility ; Freeze-thaw cycle ; Freezing ; Soil ; Soil properties ; Soil temperature ; Turkey
  • Cycle gel-dégel ; Erodabilité ; Erzurum ; Gel ; Propriétés du sol ; Sol ; Température du sol ; Turquie
  • , number of freezing and thawing cycles and freezing temperatures.
  • This study aims to determine the effects of freezing and thawing processes on the wet aggregate stability of Turkish soils formed from different parent materials, for different aggregate size groups, soil moisture contents at the time of freezing
  • Freeze-thaw simulations on quartz-micaschist and their implications for weathering studies on Signy Island, Antarctica
  • Antarctique ; Cycle gel-dégel ; Géographie physique ; Micaschiste ; Météorisation ; Roche anisotropique ; Roche métamorphique ; Simulation ; Technique de recherche
  • Describes freeze-thaw simulations. Shows anisotropic rocks have asymmetric freeze penetration and that this affects breakdown processes.-(AJC)
  • A review of the influence of freeze-thaw cycles on soil geotechnical properties
  • Canada ; Cold area ; Freeze-thaw cycle ; Geotechnics ; Periglacial features ; Permafrost ; Quebec ; Soil properties
  • Canada ; Cycle gel-dégel ; Géotechnique ; Pergélisol ; Propriétés du sol ; Périglaciaire ; Québec ; Zone froide
  • Freeze-thaw cycling affects the geotechnical properties of soils and must be taken into account when selecting soil parameters for stability and deformation analysis of slopes, embankments and cuts in cold regions, especially those underlain
  • by permafrost. This review examines methods of investigation, testing techniques and the impact of freeze-thaw processes on the physical and mechanical properties of soils.
  • Diurnal freeze-thaw depth in rockwalls: field measurements and theoretical considerations
  • Freeze-thaw cycle ; Japan ; Mountain ; Rock ; Temperature ; Weathering
  • Cycle gel-dégel ; Japon ; Montagne ; Météorisation ; Roche ; Température
  • but both diurnal and seasonal freezing occur. Diurnal frost and thaw depths were determined from the field data and compared with the theoretical values calculated by the modified Berggren equation. The seasonal frost depth, which could not be directly
  • determined from the field data, was also estimated on the basis of the analysis of the diurnal freeze-thaw depths.
  • Evidence for freeze-thaw events and their implications for rock weathering in northern Canada : II. The temperature at which water freezes in rock
  • British Columbia ; Canada ; Freeze-thaw cycle ; Rock ; Temperature ; Threshold ; Weathering
  • British Columbia ; Canada ; Cycle gel-dégel ; Eau de la roche ; Météorisation ; Roche ; Seuil ; Température
  • Data collected from northern Canada indicate that the temperature at which freezing occurs can vary substantially, even for the same site. The results indicate that any form of freeze-thaw event counting, in the absence of some indicator
  • of the presence of water and that it actually froze, is flawed, as thermal conditions alone are not adequate to indicate the occurrence or not of actual freeze-thaw weathering events. These data suggest that evaluations of freeze-thaw occurrence based simply
  • The freeze-thaw weathering regime at a section of the Niagara Escarpment on the Bruce Peninsula, southern Ontario, Canada
  • Canada ; Cryergie ; Cycle gel-dégel ; Géographie physique ; Humidité ; Méthodologie ; Météorisation ; Ontario ; Périglaciaire ; Température ; Zone froide
  • Fewer freeze-thaw cycles were recorded in the air than at 1 and 3.5 cm in the bedrock, between December 1983 and April 1984. The number of cycles that could be declared geomorphologically effective according to established temperature criteria
  • was normally less than half the total number of freeze - thaw cycles recorded in both air and bedrock. Under the current temperature regime at the field site, few effective cycles are capable of penetrating more than 5 cm into the free face.
  • A laboratory simulation of rock breakdown due to freeze-thaw in a maritime antarctic environment
  • Antarctique ; Cycle gel-dégel ; Gélifraction ; Géographie physique ; Milieu marin ; Méthodologie ; Météorisation ; Périglaciaire ; Roche cristalline ; Signy Island ; Simulation
  • Results of freeze-thaw simulations on three large blocks of quartz-micaschist are presented. Identification of three types of water to ice phase change from temperature and ultrasonic measurements. It is suggested that the type of phase change
  • results from a particular combination of rock moisture content, solute concentration, freeze amplitude, and rate of fall of temperature. The temperature at which ice thawed inside the rock (-0.7 to 1.9oC) was also found, and this indicates the possibility
  • of freeze-thaw effects without positive temperatures.
  • Structure and porosity of smectitic mudrocks as affected by experimental wetting-drying cycles and freezing-thawing cycles
  • Badland ; Clay mineral ; Drought ; Erosion rate ; Experimentation ; Freeze-thaw cycle ; Micromorphology ; Moisture ; Porosity ; Pyrénées ; Sedimentary rock ; Soil erosion ; Spain ; Weathering
  • Argile minéral ; Badland ; Cycle gel-dégel ; Erosion des sols ; Espagne ; Expérimentation ; Humidité ; Micromorphologie ; Météorisation ; Porosité ; Pyrénées ; Roche sédimentaire ; Sécheresse ; Vitesse d'érosion
  • , laboratory experiments were carried out to investigate how freezing-thawing or wetting-drying cycles, under controlled conditions, affect structure and porosity. Data from wetting-drying cycles showed that changes in water content alone did not produce deep
  • structural modifications. A mechanism of alteration of soil sructure during freezing-thawing cycles is proposed.
  • The classification and assessment of freeze-thaw erosion in Tibet
  • China ; Classification ; Freeze-thaw cycle ; Geographical information system ; Index ; Precipitation ; Soil ; Soil erosion ; Spatial distribution ; Temperature ; Tibet ; Vegetation
  • Chine ; Classification ; Cycle gel-dégel ; Distribution spatiale ; Erosion des sols ; Indice ; Précipitation ; Sol ; Système d'information géographique ; Température ; Tibet ; Végétation
  • Based on the analysis of impact factors of free-thaw erosion, this paper chooses 6 indexes, including the annual temperature range, annual precipitation, slope, aspect, vegetation and soil, to build the model for relative classification of freeze
  • -thaw erosion using weighted and additive methods, and realizes the relative classification of the freeze-thaw erosion in Tibet with the support of GIS software. Then a synthetic assessment of freeze-thaw erosion in Tibet has been carried out according
  • Physical deterioration of sedimentary rocks subjected to experimental freeze-thaw weathering
  • Building materials ; Experimentation ; Freeze-thaw cycle ; Geotechnics ; Lithology ; Sandstone ; Sedimentary ; Sedimentary rock ; Weathering
  • Cycle gel-dégel ; Expérimentation ; Grès ; Géotechnique ; Lithologie ; Matériaux de construction ; Météorisation ; Roche sédimentaire ; Sédimentaire
  • This paper addresses the influence of pre-existing flaws on the durability of ten sedimentary rocks under experimental freeze-thaw weathering. Results suggest that the presence or absence of rock flaws alone does not control deterioration mode
  • Evidence for freeze-thaw events and their implications for rock weathering in northern Canada
  • British Columbia ; Canada ; Chemical erosion ; Cold area ; Experimentation ; Freeze-thaw cycle ; Meltwater ; Temperature ; Weathering
  • British Columbia ; Canada ; Cycle gel-dégel ; Eau de fonte ; Erosion chimique ; Expérimentation ; Météorisation ; Température ; Zone froide
  • . Temperature data were collected at 1 min intervals for 1 year. These data provide unequivocal proof for the occurrence of the freezing and thawing of water on and within the rock (freeze-thaw events). It was found that the temperature at which freezing occured
  • varied significantly through the year. The change in freeze temperature is thought to be due to the chemical weathering of the material.
  • Simulation of freezing-thawing cycles in a permafrost microcosm for assessing microbial methane production under extreme conditions
  • Arctic Region ; Biogenic process ; Cold area ; Freeze-thaw cycle ; Humid environment ; Micro-organism ; Periglacial features ; Permafrost ; Russia ; Simulation ; West Siberia
  • Action biogène ; Arctique ; Cycle gel-dégel ; Micro-organisme ; Milieu humide ; Méthane ; Pergélisol ; Périglaciaire ; Russie ; Sibir' Zapadnaâ ; Simulation ; Zone froide
  • The AA. describe a new technique for the simulation of natural freezing-thawing cycles of the active layer in a permafrost microcosm. The core temperature, moisture and methane concentration and release in different depths of the microcosm can
  • be measured continuously under controlled freezing and thawing conditions. The simulation experiment provides an insight into the activity of microorganisms and turnover rates under various cryogenic conditions (i.e. frozen, partly frozen, unfrozen). The data
  • The influence of freeze-thaw cycles and soil moisture on aggregate stability of three soils in Norway
  • Clay mineral ; Cold area ; Freeze-thaw cycle ; Norway ; Rainfall simulation ; Soil ; Soil erosion ; Soil moisture ; Soil properties ; Winter
  • Argile minéral ; Cycle gel-dégel ; Erosion des sols ; Hiver ; Humidité du sol ; Norvège ; Norvège du Sud ; Propriétés du sol ; Simulation de pluie ; Sol ; Zone froide
  • The aim of this study was to quantify the effect of variable freeze-thaw cycles and soil moisture conditions on aggregate stability of 3 soils (silt, structured clay loam-clay A and levelled silty clay loam-clay B), which are representative of 2
  • erosion prone areas in southeastern Norway. A second aim was to compare aggregate stabilities measured by the Norwegian standard procedure (rainfall simulator) and the more widely used wet-sieving procedure. Freezing and thawing decreased the rainfall
  • Characteristics of the seasonal thawing of permafrost in Mongolia
  • Cryopedology ; Freeze-thaw cycle ; Mongolia ; Periglacial features ; Permafrost ; Season ; Soil science ; Summer ; Thawing
  • Cryopédologie ; Cycle gel-dégel ; Dégel ; Eté ; Mongolie ; Pergélisol ; Pédologie ; Périglaciaire ; Saison
  • The paper presents the problem of the permafrost occurrence in Mongolia and discusses the processes of its summer thawing, depending on geographical environmental conditions. These problems are dealt with on the basis of literature and the present
  • Frost heave and dry density changes during cyclic freeze-thaw of a silty clay
  • China ; Clay ; Cold area ; Experimentation ; Freeze-thaw cycle ; Frost ; Geotechnics ; Qinghai ; Railway ; Tibet
  • Argile ; Chemin de fer ; Chine ; Cycle gel-dégel ; Expérimentation ; Gelée ; Géotechnique ; Qinghai ; Tibet ; Zone froide
  • Open-system frost heave tests were performed on a silty clay using a lower boundary condition of +2°C and unidirectional freezing at -10°c from the surface, or freezing and thawing with an upper boundary temperature that cycled from -10°C to +10°C
  • or from -10°C to 0°C. The amont of frost heave, the distribution of moisture at the end of the experiment and the final dry density profiles all differed for the 3 cases. The experiments demonstrate that freeze-thaw history is important in assessing
  • Cold area ; Freeze-thaw cycle ; Polar region ; Weathering
  • Cycle gel-dégel ; Météorisation ; Région polaire ; Zone froide
  • Freezing effects on aggregate stability of soils amended with lime and gypsum
  • Agropedology ; Clay mineral ; Cultivated land ; Freeze-thaw cycle ; Land improvement ; Soil ; Soil properties ; Soil water ; United States of America
  • Agropédologie ; Amélioration des terres ; Argile minéral ; Cycle gel-dégel ; Eau du sol ; Etats-Unis ; Propriétés du sol ; Sol ; Sol cultivé
  • The objectives of the laboratory study were to determine the effects of freeze-thaw cycles, water content at freezing, and lime and gypsum additions on the aggregate stability of 6 agriculturally important US soils differing in texture, mineralogy
  • Quantifying the effect of a freeze-thaw cycle on soil erosion : laboratory experiments
  • Cold area ; Experimentation ; Freeze-thaw cycle ; Overland flow ; Rill wash ; Soil erosion ; Soil moisture
  • Cycle gel-dégel ; Ecoulement superficiel ; Erosion des sols ; Expérimentation ; Humidité du sol ; Ruissellement ; Zone froide
  • The AA. quantitatively test the hypothesis that soil freeze-thaw (FT) processes significantly increase the potential for upland hillslope erosion during run-off events that follow thaw. They selected a highly frost-susceptible silt to obtain
  • an upper bound on FT effects, and completed 3 series of 6 experiments each to quantify differences in soil erosion and rill development in a bare soil following a single FT cycle. As both FT and C results were highly sensitive to initial conditions, minimum
  • Deformation of laminated silt loam due to repeated freezing and thawing cycles
  • Alpes ; Argile ; Cycle gel-dégel ; Expérimentation ; France ; Géographie physique ; Limon ; Micromorphologie ; Périglaciaire ; Sol ; Technique de recherche
  • L'effet répété des cycles gel-dégel sur un limon argileux lité produit expérimentalement est étudié dans le but de comprendre mieux la genèse des macro-et microstructures observées dans les formations loessiques de l'Europe du Nord-Ouest.
  • Soil freeze-thaw-induced changes to a simulated rill : potential impacts on soil erosion
  • Cold area ; Freeze-thaw cycle ; Freezing ; Gully erosion ; Mass movement ; Model ; Rill wash ; Sediment transport ; Soil erosion
  • Cycle gel-dégel ; Erosion des sols ; Gel ; Modèle ; Mouvement de masse ; Ravinement ; Ruissellement ; Transport sédimentaire ; Zone froide
  • The objective of this study was to measure the effects of one of the soil processes that affect rill geometry, soil freeze-thaw (FT) cycling. An unvegetated rectangular rill was subjected to 2 FT cycles, each lasting several days, in a controlled
  • laboratory setting. The FT cycling increased the water content and reduced the cohesion in the surface soil along the rill sufficiently to induce soil slumps and mud flows along the sidewalls of the rill. These mass failures changed the rectangular rill