Heat Transfer Between Concrete Bored Cast-In-Place Piles and Surrounding Frozen Soil in Ice-Rich Area

摘要

Based on the concrete test of foundation pile and the heat transfer theory between pile and soil, the heat transfer rule of pile and soil in ice-rich tundra is studied. The results show that the heat flow of foundation pile can be divided into vertical and horizontal heat flows. The vertical heat flow mainly occurs at the top of the pile and reaches the maximum value of 15.36w /m2 on 3d. It caused the pile top temperature to drop so fast that it dropped below 0°C in 3d. The value of the horizontal heat flow is 2~3 times that of the vertical heat flow. Its distribution is in descending order: the middle, the top and the bottom of the pile. The maximum temperature difference between pile center and pile wall is 6.8°C because of transverse heat flow. Local high temperature zone is formed inside the pile due to the relatively slow absorption process of thawing permafrost. Then the temperature dropped rapidly, reaching 0°C at 28d. The maximum disturbance radius in the frozen soil reaches 1.5m. Insulation layer can be added to the outside of the foundation pile during construction to obtain more uniform concrete temperature field, so as to improve the concrete strength and reduce the disturbance to the frozen soil. The construction period should be in summer.