Study on Thermal Disturbance of Frozen Soil Around Piles by Concrete Hydration Heat

Abstract

In order to study the influence of the heat of hydration of concrete on the thermal disturbance of the frozen soil around the pile during the construction of cast-in-place piles in permafrost regions, a two-dimensional temperature field numerical model was established with non-steady state based on the heat conduction control equation and the freezing-thawing phase transition process. This model has been used to analyze and discuss the refreezing process of the concrete pile foundation, the heat flow transfer process between the pile foundation and the frozen soil, and the positive temperature curing process of the pile body. The research results have shown that the refreezing process of the pile foundation is a slow process. It took 28 days after the completion of the pile foundation construction that the negative temperature arose at the bottom of the pile. And 196 days after construction the temperature at the center of the pile dropped to negative. The heat brought by the cast-in-place pile is mainly released to the surrounding soil through the horizontal heat flow, and the thermal conductivity of the soil has a greater influence on this process.