多年冻土区桩基竖向承载力的预报模型

通过多年冻土区大气温度与地温关系，得出季节冻结期和季节融化期地面温度，进一步确定季节冻结及季节融化深度。综合地面温度得出多年冻土厚度随时间变化的关系，将大气温度、地面温度、融冻层厚度及多年冻土厚度变化建立起与时间相关的联系方程。考虑大气温度变化分析桩土相互作用并建立桩土相互作用模型。综合联系方程、桩土分析模型及冻土地区建筑地基基础设计规范中的单桩竖向承载力公式，建立了联系大气温度、地面温度、季节融冻深度、多年冻土层厚度变化与桩基承载力的关系预报模型，为预测在设计使用年限内随着大气温度变化桩基的工作状况提供较为科学的依据。

A prediction model of vertical bearing capacity of pile foundation in permafrost region

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.