冻结时间对冻土抗压强度影响的试验分析

Experimental Analysis of the Influence of Freezing Time on Compressive Strength of Frozen Silty Clay

为了研究不同冻结时间及含水率对冻结粉质黏土无侧限抗压强度的影响,在负温条件下对不同含水率粉质黏土进行了不同冻结时间的无侧限抗压强度试验。结果表明随着冻结时间的增加,冻结粉质黏土无侧限抗压强度逐渐增大且增大趋势逐渐减小,应力-应变曲线的弹性段得到延长,应力达到峰值后下降段斜率逐渐增大,表现出依赖于冻结时间的冻脆性特征;在17%～29%范围内,随着含水率的增大,无侧限抗压强度逐渐降低,破坏应变逐渐增大,破坏形式由脆性破坏向塑性破坏转变。

In order to study the effect of different freezing time and water content on the unconfined compressive strength of frozen silty clay, the unconfined compressive strength tests of silty clay with different water contents under different freezing time were carried out under the negative temperature conditions. The results show that with the increase of freezing time, the unconfined compressive strength of frozen silty clay gradually increased while its increasing tendency decreased;the elastic section of stress-strain curve was extended, and the slope of the descending section gradually increased after reaching the stress peak. The freezing-brittleness characteristics that depend on the freezing time were exhibited. In the range of 17%~29%, with the increase of water content, the unconfined compressive strength gradually decreased, the failure strain increased gradually, and the failure mode changed from brittle failure to plastic failure.