江淮膨胀土自由膨胀率特征

自由膨胀率是公路及其他行业膨胀土判别与分类的常用指标,研究自由膨胀率特征对指导膨胀土判别分类具有重要意义。本文依托皖中地区在建的合(肥)六(安)高速公路,开展了自由膨胀率及其他相关性指标的试验研究,分析了皖中膨胀土的自由膨胀率特征。研究表明:皖中地区膨胀土自由膨胀率与反映膨胀本质的指标蒙脱石含量,以及液限、塑性指数等间接性判别指标具有较好的相关性,可将其用作膨胀土判别与分类的指标;分类实践发现《公路路基设计规范》所推荐的自由膨胀率分级评判标准不能适用于皖中地区膨胀土;根据研究结果给出了具有合理分类特征的分类标准建议。

CHARACTERISTICS OF FREE SWELLING RATIO FOR EXPANSIVE SOIL IN MIDDLE ANHUI PROVINCE

Free swelling ratio is a frequent index for classification and identification of expansive soils in highway and other professions.In the HeFei-LuAn expressway,test studies on the free swelling ratio and related indices are carried.The characteristics are analysed.The results indicate that the free swelling ratio of expansive soil in the middle of AnHui province is lower than the average level of China.Its relationship with smectite content is preferable.Its relationship with liquid limit and plastic index are good too.These indices can be integrated for classification and identification of expansive soils.By means of practice of identification,the results show that the consistence can't be got using a single index and the grading standard of free swelling ratio doesn't fit expansive soil in the middle of AnHui.A new grading standard possessing a better applicability is suggested.