Sensitivity of Permafrost Adjacent to Bored Pile in Wetland Tundra During Concrete Hydration Heating

Abstract

The permafrost in wetland area is very sensitive to temperature change due to its special geological conditions. By observing the temperature data of the pile-soil junction of the bored concrete pile, as well as measuring the geotechnical parameters and thermophysical parameters of the soil around the pile, it statistically analyzes the significant correlation factors related to the time when the temperature of the pile-soil junction rises to the peak, including the dry density and liquid index of the frozen soil. The formula for calculating peak time is summarized and the fitting effect is compared. The results show that peak time is positively correlated with dry density and obeys cubic curve. It is negatively correlated with the liquid index and follows the growth function curve. The peak time was not significantly correlated with the buried depth of the temperature sensor, peak temperature corresponding to the peak time, natural ground temperature, original temperature of pile wall, soil thermal conductivity, volume heat capacity, natural moisture content and plasticity index of frozen soil. The influence of concrete ratio on peak time is significant, and its correction coefficient follows S-shaped curve.