石灰改良膨胀土的强度特性试验研究

Experimental Study on Strength Characteristic of Lime Modified Expansive Soil

石灰作为一种外加剂,用来改良膨胀土作为路基的填料,但石灰改良土击实曲线比较平缓,最优含水率较难确定,而且,在最优含水率附近压实是否就能达到较高的强度,也难以确定。针对该问题,对不同初始含水率下石灰改良膨胀土的无侧限抗压强度、CBR强度进行试验研究,并对干湿循环影响下的改良膨胀土CBR强度进行试验。结果表明:石灰改良膨胀土在初始填筑含水率稍大于击实曲线所反应的最优含水率情况下能够达到较高的强度,建议在实际施工中充分考虑初始含水率这一填筑条件对石灰改良土改良效果的影响。

The lime,as an admixture,is used to modify the expansive soil used for the stuffing of roadbed.However,the compaction curve of lime modified soil is smoother.It is harder to define the optimal water content,and it is also hard to define whether or not the compaction near the optimal water content can achieve the higher strength.Aiming at this problem,the experimental study is carried out for the unconfined compressive strength and CBR strength of lime modified expansive soil with the different primary water contents,and the experiment is implemented for CBR strength of modified expansive soil under the influence of dry and wet cycles.The result shows that the lime modified expansive soil can achieve the higher strength under the condition of the water content of the primary filling being larger than the optimal water content reacted by the compaction curve.The article proposes to fully consider the influence of the primary water content on the modifying effect of lime modified soil.