不同因素对浅表土导热系数影响的试验研究

Effect of Different Factors on the Heat Conduction Coefficient of Shallow Top Soil

土体导热系数是预测人工冻结温度场发展、冻结壁厚度的重要参数,主要取决于固体颗粒成分、含水率和土体密实程度。本文以南京地区浅表土为研究对象,开展了常温与-10℃冻结时含水率、干密度对淤泥质黏土、淤泥质粉质黏土、粉砂导热系数的影响规律研究。研究结果表明:土质、含水率、干密度对导热系数影响显著,在试验含水率与干密度范围内,导热系数随含水率、干密度增加呈近似线性规律升高;冻土导热系数大于常温土导热系数,随含水率增加冻土导热系数的增加幅度与干密度相关。

The heat conduction coefficient of soil is an important parameter for predicting the development of artificial freezing temperature field and thickness of frozen wall.The parameter mainly depends on the factors including the component of solid grain,moisture content and density of the soil.This article studies the influence of some factors including moisture content,dry density and temperature on the heat conduction coefficient of soil such as mucky clay,mucky silty clay and silty sand under normal temperature and ten degrees below zero.The results show that different kinds of soil,moisture content and dry density affect the conduction coefficient obviously,and in the range of moisture content and dry density tested,the coefficient increases linearly with increase of moisture content and dry density.What＇s more,the coefficient of frozen soil is greater than that of soil at normal temperature.In addition,with moisture content increasing the coefficient growth of frozen soil is relevant to the dry density.