Influence of permafrost degradation on piles bearing capacity

The permafrost zone is one of the main natural systems in the Russian Federation that are exposed to global warming. The temperature of permafrost soils changes, the seasonal thaw zone increases, the process of permafrost degradation is started, influencing the strength properties of the soils. The study sought to assess climate change in terms of the impact on the bearing capacity of the soil under buildings and structures built in the 1960s and 1980s on the principle of maintaining the permafrost condition of soils. On the basis of published archival and forecast data on the increase rate in the active layer thickness and the rising trends in the temperature of permafrost soils for four geographical regions of Russia (North of the European part, North of Western Siberia, Middle Siberia, Yakutia) a reduction in the bearing capacity of the standard reinforced concrete pile was determined (35x35 cm section, 10 m long). The study showed that, for most regions, the reduction in the bearing capacity of the pile is currently on average level (10-20 %). However a high (>30%) decrease is expected by 2050.