冻融循环下吉林延边膨胀土水泥改良研究

Study on engineering properties of expansive soil and properties of cement-modified expansive soil in Yanbian area of Jilin province under freeze-thaw cycles

吉林省延边地区分布大量膨胀土,因其每年都经历冻融循环,导致延边地区部分路基工程的边坡开裂、滑坡、坍塌等工程灾害.为了提高该地区膨胀土的抗剪强度,加入2%,4%,6%,8%,10%水泥改良膨胀土进行不固结不排水三轴实验,测出其抗剪强度和粘聚力.结果表明,水泥量为6%的改良膨胀土比其它水泥量的改良膨胀土粘聚力和抗剪强度改良效果更加明显.

A large amount of expansive soil is distributed in Yanbian area of Jilin province in China.These expansive soils are experiencing freeze-thaw cycles every year,which has led to the slope cracking,landslide,collapse and other engineering disasters of some roadbed projects in Yanbian area.In order to improve the shear strength of expansive soil in Yanbian area of Jilin province,five kinds of 2%,4%,6%,8%,10%portland cement were added under freeze-thaw cycles,the unconsolidated and undrained triaxial tests were carried out on five different parameters of cement-modified expansive soil to measure its shear strength and cohesion.The results show that the improved expansive soil with 6%cement parameter is more effective than that with other parameters through cohesion and shear strength,which provides some experiences and methods for the improvement of expansive soil in subgrade engineering in seasonal frozen area.