含盐量对亚硫酸盐渍土抗剪强度影响的试验

发布时间：2018-05-14 01:06

本文选题：土壤 + 盐　；参考：《农业工程学报》2016年06期

【摘要】：为探讨含盐量对盐渍土抗剪强度的影响,该研究对采自于青海柴达木盆地大柴旦盐湖地区的盐渍土进行了洗盐试验以获得素土试样;根据该区盐渍土类型及盐渍化程度,在洗盐后土体中分别加入不等量的无水硫酸钠(Na2SO4),以获得不同含盐量的人工配制硫酸盐渍土,并对上述不同含盐量的人工配制硫酸盐渍土开展室内直接剪切试验。试验结果表明,洗盐试验后土体中的易溶盐离子含量及p H值均显著低于洗盐前盐渍土;当土体密度和含水量分别为1.41 g/cm3和25.68%时,洗盐后土体粘聚力c值和内摩擦角φ值分别为14.8 k Pa和26.5°,均高于洗盐前盐渍土的粘聚力值(6.7 k Pa)和内摩擦角值(24.6°);不同含盐量梯度条件下的人工配制硫酸盐渍土的粘聚力和内摩擦角,随土体含盐量增加均表现出先减小后增加的变化特征。当含盐量由0.74%增至5.17%时,人工配制硫酸盐渍土粘聚力c值和内摩擦角φ值均呈逐渐减小的变化规律,当土体含盐量由5.17%增至14.17%时,人工配制硫酸盐渍土粘聚力c值和内摩擦角φ值均表现出增加的变化规律,且当含盐量为5.17%时,其粘聚力c值和内摩擦角φ值分别为8.3 k Pa和26.1°,均为最小值,即该值对应的含盐量值即为人工配制硫酸盐渍土的含盐量阈值。本项研究成果对于进一步探讨含盐量变化对盐渍土抗剪强度影响,及含盐量变化与盐渍土粘聚力和内摩擦角之间的关系等方面具有理论研究价值和实际意义。
[Abstract]:In order to study the effect of salt content on the shear strength of saline soil, the salinized soil collected from the salt lake area of Qaidam Basin, Qinghai Province, was washed with salt to obtain the sample of plain soil, and according to the type of saline soil and the degree of salinization in this area, Different amounts of anhydrous sodium sulfate (Na _ 2SO _ 4) _ 4 were added to the soil body after salt washing in order to obtain artificially prepared sulphate soil with different salt content, and the laboratory direct shear test was carried out on the artificially prepared sulphate soil with different salt content. The results showed that the soluble salt ion content and pH value in soil after salt washing test were significantly lower than those in saline soil before washing salt, and when the soil density and water content were 1. 41 g/cm3 and 25. 68 g/cm3, respectively, After salt washing, the cohesive force c and internal friction angle 蠁 were 14.8 KPA and 26.5 掳, respectively, which were higher than that of saline soil before washing (6.7 KPA) and internal friction angle (24.6 掳). Cohesion and angle of internal friction, With the increase of soil salt content, the variation of soil salt content decreases first and then increases. When the salt content increases from 0.74% to 5.17%, the cohesive force c value and the internal friction angle 蠁 value of the artificial sulfate saline soil decrease gradually, and when the salt content of the soil increases from 5.17% to 14.17%, The cohesion c value and internal friction angle 蠁 value of artificial sulphate soil both show the increasing law of variation, and when the salt content is 5.17, the cohesion c value and the internal friction angle 蠁 value are 8.3 KPA and 26.1 掳, respectively, which are the minimum values, respectively, when the salt content is 5.17, the cohesion C value and the internal friction angle 蠁 value are respectively 8.3 KPA and 26.1 掳, respectively. The salt content value corresponding to this value is the threshold value of the salt content of the artificially prepared sulphuric acid saline soil. The results of this study have theoretical and practical significance for further study on the influence of salt content change on the shear strength of saline soil and the relationship between salt content change and cohesion and internal friction angle of saline soil.
【作者单位】：中国科学院青海盐湖研究所;中国科学院大学;青海大学地质工程系;
【基金】：国家自然科学基金资助项目(41162010;41572306) 中国科学院“百人计划”资助项目(Y110091025);中国科学院青海盐湖所“青年基金”项目资助(Y360441058)
【分类号】：S156.4

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