中文摘要：

膨胀土灾害治理一直是岩土工程界的重要课题之一，掺加改性材料是改善膨胀土工程特性的重要方法。制作掺加不同比例的石灰、水泥以及砂的改性膨胀土试样，通过物理性质试验、膨胀性试验和强度试验结果的比较，确定三种改性材料的最佳掺比。在此基础上，进一步比较三种改性材料最佳掺比下对膨胀土的改性效果。试验结果表明，水泥和石灰比砂能更好地减小膨胀土的膨胀率，提高膨胀土的强度。研究结果为工程实践中改性材料的合理选择提供了重要参考。

英文摘要：

The hazard preventing of expansive soil has been one of important issues in geotechnical engineering area, and mixing modifying materials with expansive soils is the important method improving engineering characteristics of expansive soil. In this study, an expansive soil, obtained from Jingzhou, Hubei Province, China, was mixed with lime, cement and sand respectively, and the laboratory tests were conducted to measure the physical property, the swelling-shrinkage property and sheer strength of the modified expansive soil. On the basis of the testing results, the optimum lime, cement and sand contents were determined. Eventually, the effects of lime, sand and cements on the swelling potential and strength of the expansive soil were compared. The results showed that lime and cement were better than sand in reducing the swelling potential and increasing the strength of the expansive soil. The testing results provide important references for the rational choose of modifying materials in engineering practice.