初始含水率对膨润土膨胀特性的影响

Influence of Initial Water Content on Swelling Characteristics of Bentonite

为了获得初始含水率对膨润土膨胀特性的影响规律,进行了不同初始含水率条件下无荷膨胀率、有荷膨胀率和膨胀力室内试验。试验结果表明:中等膨胀势膨润土在吸水饱和过程中无荷膨胀率、有荷膨胀率逐渐增大,且经历快速膨胀期、缓慢膨胀期和膨胀稳定期3个阶段。初始含水率越小,快速膨胀期历时越短,膨胀速率越快。随着初始含水率的增加,膨润土的无荷膨胀率、有荷膨胀率和膨胀力均呈减小趋势,且无荷膨胀率、有荷膨胀率线性递减,而膨胀力与初始含水率呈现良好负指数关系。

In order to obtain the influence of initial water content on swelling characteristics of bentonite,the laboratory tests of swelling ratio without pressure,swelling ratio under pressure and swelling force were conducted under different initial water content. The results show that the swelling ratio without pressure and the swelling ratio under pressure of bentonite with moderate expansion potential increase gradually in the process of absorbing water and saturating. The swelling curves have three stages including rapid expansion period,slow expansion period and expansion stable period. The smaller the initial water content is,the shorter the rapid expansion period continues and the faster the swelling rate becomes. With the increase of the initial water content,the swelling ratio without pressure,the swelling ratio under pressure and swelling force of bentonite decrease. Meanwhile,the swelling ratio without pressure and the swelling ratio under pressure decrease linearly,and a good negative exponent relation is obtained between the swelling force and the initial water content.