砂类盐渍土（硫酸盐）起胀含盐量的试验研究

发布时间：2018-10-12 17:10

【摘要】：河西走廊地区广泛分布着粗颗粒硫酸盐渍土,对该地区建筑物、构筑物,农业等方面都造成严重影响。目前,国内学者对细颗粒土的盐胀变形规律的研究已较为深入,以利用回归正交设计法得到盐胀率的计算公式,并由此推算出细粒土的起胀含盐量和起胀含水量值,而对砂类土的起胀含盐量ω0的确定还比较模糊。 作者通过对8种不同级配的非饱和砂类硫酸盐渍土的80个试验试样,在含水量为7%,不同含盐量时,进行单次降温(降温过程为20℃→5℃→0℃→5℃→-10℃)盐胀试验研究,来探究起胀含盐量,不同孔隙率对盐胀变形的影响及空隙率与起胀含盐量之间的关系。实验结果表明,盐胀率η=0.1%可作为砂类土发生盐胀变形的判断依据；砂类硫酸盐盐渍土的起胀含盐量ω0与孔隙率n的关系可用分段函数表示,当孔隙率为0.55时,砂类土的起胀含盐量最高,约为0.51%；当孔隙率n低于此值时,起胀含盐量ω0随着孔隙率n增加而呈现二次抛物线单调递增关系；当孔隙率n高于此值时,起胀含盐量ω0随着孔隙率n增加而呈现二次抛物线单调递减关系。砂类硫酸盐盐渍土发生盐胀的敏感温度区间在0～-5℃之间。
[Abstract]:Coarse sulphate soil is widely distributed in Hexi Corridor, which has serious influence on buildings, structures, agriculture and so on. At present, the domestic scholars have deeply studied the law of salt swelling deformation of fine granular soil. The formula of salt expansion rate is obtained by using regression orthogonal design method, and the swelling salt content and swelling water content of fine granular soil are calculated. However, the determination of the swelling salinity 蠅 0 of sandy soils is rather vague. In this paper, 80 test samples of 8 different grades of unsaturated sand sulphate soil are studied. When the water content is 7and the salt content is different, a single cooling test is carried out (20 鈩，

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