严寒地区深基坑土体温度场动态变化研究

Study on Dynamic Change of Soil Temperature Field of Deep Foundation in Severe Cold Area

对冬季期间呼和浩特地铁车站主体深基坑进行现场土体温度测试,分析测试孔温度变化规律,得出基坑截面冻结范围;同时,提出水热力耦合模型,拟合实测气温数据得出基坑表层土体温度曲线,通过建立数值模型对基坑土体温度场进行模拟。并比对现场试验数据对模型进行验证,研究严寒条件下深基坑土体温度场动态变化规律。结果表明:基于水热力耦合模型基坑温度场模拟仿真,与现场检测试验数据变化规律基本相同,可作为基坑温度场模拟计算有效手段,为进一步分析研究土体冻胀应力提供基础支撑。

In the winter,the soil temperature of the deep excavation pit in Hohhot metro station is tested,the law of soil temperature change in the test hole is analyzed,and the freezing range of the deep excavation is obtained.Meanwhile,the coupled model of Moisture Heat and Stress Fields during soil freezing is proposed,the temperature curve of the surface soil is obtained by fitting the measured temperature data,and the soil temperature field of the deep excavation is simulated by establishing the numerical analysis model.By comparing with the site measurement data,the dynamic change law of soil temperature field in deep excavation under severe cold condition is studied.The results show that the simulation of temperature field in deep excavation based on the coupled model of Moisture Heat and Stress Fields is basically the same as the change law of site measurement data,which can be used as an effective method for the simulation calculation of temperature field in deep excavation pit and provide the basic support for further analysis and research of soil frost heave stress.