Influence of the specific regime of snow deposits on permafrost basements in the cities of the cryolithozone (by the example of the Norilsk industrial region)

Abstract

With increasing snowfalls and rising winter temperatures in the Arctic regions of Russia (against the background of almost the same summer values), the role of solid precipitation in the formation of the temperature and humidity regimes of seasonally thawed and upper horizons of permafrost grounds becomes extremely important. No regular observations of snow accumulation in built-up areas were conducted in the Arctic settlements. This article presents for the first time the results of snow measurements in urbanized areas of the Norilsk region, and assesses the warming effect of snow cover on the permafrost grounds and foundations. The problems that arise during the mechanical redistribution of snow are identified. In some areas the thickness of the snow cover (near the city of Norilsk) by the end of March can reach 200 cm; in February, the average monthly value for the last 15 years amounts 69 cm, and in the city the height of snow dumps ranges from 2 to 5 m. The warming effect of snow cover on the permafrost layer enhances as the snow height increases from 0 to 2–2.5 m, and then remains unchanged. Large masses of snow existing for many decades in almost the same places (together with the snow drifts of the air from the ventilated subfields) result in the development of degradation tendencies within the permafrost. A slight temperature rise was noted in grounds under 30–40% of the operated objects (as compared with the design values), which causes deformation of the structures.

Keywords

• фундаменты
• деформации конструкций
• механическое перемещение cнега
• свойства снежного покрова
• вечная мерзлота
• теплоизолирующие свойства
• устойчивость