斥水剂作用下土壤物理性质变化规律试验研究

采用十八烷基伯胺(OCT)对亲水土壤斥水化,进行斥水土壤的临界含水率试验、界限含水率试验以及击实试验。通过试验结果分析OCT对土壤物理性质的影响关系,获得OCT质量分数与土壤初始含水率、液限、塑限、最优含水率、最大干密度的关系。结果表明:亲水及斥水性土壤为高液限黏土,土壤状态为坚硬;随着斥水土壤初始含水率的增加,土壤斥水等级出现先增后减的变化规律;斥水土壤液限随着OCT质量分数的增大而减小,塑限随着OCT质量分数的增大而增大;最大干密度及最优含水率随着土壤斥水等级增大而增大,增幅平均为5.7%。上述研究成果可为斥水土壤工程应用提供试验基础。

Experimental Study on the Change of Soil Physical Properties underthe Action of Water Repellent Agent

The octadecylamine (OCT) was used to re-hydrate the hydrophilic soil. The critical moisture content tests, boundary moisture content tests and compaction tests of the water-repellent soil were carried out. The relationships of OCT mass fraction to soil initial water content, liquid limit, plastic limit, critical water content and maximum dry density were obtained by analyzing the effect of OCT on soil physical properties. The results showed that both hydrophilic soil and water repellent soil had a high liquid limit, and they were classified as hard soil. The repelling level of water-repellent soil increased first and then decreased with the increase of initial water content. The water limit of the water-repellent soil decreased with the increase of the OCT mass fraction, while the plastic limit increased with the increase of the OCT mass fraction. The maximum dry density and critical moisture content increased with the increase of soil water repellent level, and the average increment was 5.7%. These results can provide a test basis for the application of water-repellent soil in engineering.