增湿减湿对黄土湿陷性的影响研究

Research on the Impact of Humidification and Dehumidification on the Loess Collapsibility

黄土湿陷性的研究主要局限于狭义浸水饱和后的最终沉降量;但实际工程中常遇到的是不同增湿减湿含水率产生的广义湿陷,所以研究不同增湿减湿含水率对黄土湿陷性的影响更具实际意义。通过验测定由同一土桶制备的原状、增湿和减湿试样的含水率、湿陷系数和压缩量,并结合现有相关理论对数据进行统计、对比和分析,得出不同含水率的增湿、减湿对黄土湿陷性的影响规律。结果表明:在相同条件下,湿陷系数随增湿后含水率的增大而有明显的减小,初始含水率较低比初始含水率较高对湿陷性影响大;试验所取土样的峰值压力为100 k Pa左右,增湿界限含水率大概为26%;在相同条件下,增湿减小了黄土的湿陷量,却增大了压缩量;减湿减小了黄土的压缩量却增大了湿陷量。

Loess collapsibility researches mainly confined to the narrow saturated final settlement after soaking, but generalized collapsibility produced by different humidification water content is frequently encountered in the ac- tual engineering, so it is more practically meaningful to research the effect of different water content on loess col- lapsibility. The laws of the effect of different moisture humidification and dehumidification on loess collapsibility was obtained by measuring moisture content, coefficient of collapsibility and amount of compression of undisturbed, humidifying and dehumidifying soil samples prepared in a same soil barrel, and counted, compared and analysised with the existing related theories. The results showed that, coefficient of collapsibility decreased obviously with the increase of water content after humidification, and the lower water content was easier than the higher water content to affect the collapsibility under the same conditions; The peak pressure of the test soil sample was about 100 kPa, and the humidification limit water content of the soil in this experiment is 26% ; under the same conditions, humidification decreased collapsibility deformation amount but increased compressibility deformation amount, and dehumidification decreased compressibility deformation amount but increased collapsibility deformation amount.