膨胀土的自由膨胀比分级标准研究

Study on the Grading Standard of Relative Free Swelling Ratio for Expansive Soil

介绍了一种新的膨胀土判别指标——自由膨胀比,它是10g烘干土样在分别盛有蒸馏水和柴油的标准量筒(通常为50mL)中沉积稳定时的体积之比;通过大量对比试验研究和统计分析,推荐了自由膨胀比用于膨胀潜势分级的划分标准,并对其合理性进行了验证。结果表明:采用本文推荐的划分标准有很好的聚类特征,且不同分组间平均值有一定的距离,因而能将不同膨胀潜势的土样区分开来。最后用蒙脱石含量对划分标准进行了检验,结果表明两者用于膨胀潜势分级的结果完全吻合。

A new kind of evaluation index for expansive soil--relative free swelling ratio, is introduced in this paper, which is defined as the ratio of the equilibrium sediment volume of 10 g ovendried soil sample in distilled water to that in diesel oil. The relative free swelling ratio is recommended as the grading standard used to distinguish the swelling potential grade according to the plenty of comparative experimental studies and statistical analysis, and the rationality of the evaluation index is validated. The verification results show that the grading standard in this paper has good clustering characteristics, and the mean values between different groups have certain distance, so we can use the standard to distinguish soil samples with different swelling potential. Finally the classification criteria for grading swelling potential are tested by montmorillonite content and the results are coincided with that of relative free swelling ratio.