【摘要】 利用CT扫描不同土类、不同盐类和不同盐量的室内冻结样品,结果发现:在冻结过程中,随着温度的不同,不同盐类的盐渍土在不同的温度下其内部结构存在差异.其中,氯化钠盐渍土随着温度的降低CT扫描结果为体积收缩,其密度不断增大;但是当土样冻结时,CT扫描结果为体积膨胀,其密度随着温度的降低而逐渐减小.硫酸钠盐渍土随着温度的降低,CT扫描结果为体积膨胀,其密度不断减小;当土样冻结时,CT扫描结果为体积继续膨胀,其密度更加减小.从样品对X线质量吸收系数来看,其吸收能力为:粉土≥盐≥粘土≥水.相同含盐量的粘土和粉土,在温度相同时,粉土的盐胀量大于粘土.因此,土的类型和含盐量是决定样品盐胀的主要因素.更多还原

【Abstract】 By CT scanning the freezing samples that have different soil types,salts and salt contents,the following experiment results can be seen: in the freezing process,the internal structure of the samples are different for different temperatures and saline soils.As temperature decreasing,the CT scanning sodium chloride saline soil shows that the sample’s volume is shrinking and its density increasing;but when the sample begins to freeze,the CT scanning shows that its volume is expanding and its density decreasing with temperature decreasing.To the sodium sulfate saline soil,the CT scanning shows that the sample’s volume is expanding and its density decreasing as temperature decreasing;and when the sample begins to freeze,the CT scanning shows that its volume is continuously expanding and its density decreasing more.The capacity of X-ray mass absorption coefficient ranks as silt ≥ salt ≥ clay ≥ water.Salt heaving capacity can affect the sample initial variance(dispersion).So the clay initial variance is more and its salt heaving capacity is less;the silt initial variance is less and its salt heaving capacity is more.In other words,the salt heaving capacity of silt is more than that of clay at the same salt content and temperature.Therefore the soil type and salt content are the major factors to the salt heaving.更多还原