Abstract:

Surface average air temperature was obtained in frost-thaw period based on the relationship between air temperature and ground temperature in the permafrost regions. Active-layer thickness of permafrost at any time and any space point can be determined by the relationship between air temperature and ground temperature. Furthermore, variation laws of permafrost thickness with time are obtained and the relation formula for air temperature, mean ground temperature, active-layer thickness and base plate thickness change of permafrost correlated with time are established. Soil-pile interaction is analyzed considering air temperature, and models of soil-pile interaction are bulit. Synthesizing relation formula, models of soil-pile interaction and vertical bearing capacity of single pile formula in Code for Design of Soil and Foundation of Building in Frozen Soil Region, a prediction model in which some factors of air temperature, ground temperature, active-layer thickness, permafrost thickness change correlated to the bearing capacity of pile foundation has been established, so as to provide scientific basis for predicting working conditions of pile foundation varying with the air temperature within designed life cycle.

Key words: air temperature, ground temperature, active-layer thickness, permafrost thickness, vertical bearing capacity of single pile