有机质入侵后土体压缩性状试验研究

Experimental study on soil compression properties after organic matter invasion

为了模拟不同种类有机质入侵红黏土对土体物理力学特性的影响,在红黏土中添加腐殖酸、富里酸、腐殖酸钾3种外掺有机质配制得到了不同种类和含量的人工有机质土,并进行了液、塑限对比试验;然后,对红黏土和重塑有机质土进行室内侧限压缩对比试验,分析了有机质含量、有机质种类、初始含水率对有机质土体压缩性状的影响。试验结果表明随着有机质含量的增加,土体比重减小,腐殖酸土液、塑限下降,富里酸土和腐殖酸钾土液、塑限均呈现上升趋势;当养护龄期一定时,有机质含量升高,土颗粒团聚性增强,土体的孔隙率增加,压缩性增强;有机质含量一定时,土体压缩性排序为富里酸土>腐殖酸钾土>腐殖酸土,且初始含水率高的有机质土体压缩性始终大于初始含水率较低的土体。土体压缩性与有机质种类及含量密切相关,研究结果可为后续有机质土改良与计算地基沉降和稳定性评价提供参考依据。

In order to simulate the influence of different kinds of organic matter invading red clay on the physical and mechanical properties of soil,three kinds organic matter of humic acid,fulvic acid and potassium humate were added into the red clay to prepare artificial organic soil with different contents,and the liquid-plastic limit comparative test was carried out.Then,the effects of organic matter content,organic matter type and initial moisture content on the compression properties of organic soil were analyzed by indoor closed compression test of red clay soil and remodeled organic soil.The experiment results show that with the increase of organic matter content,the proportion of soil decreases,the liquid limit of humus soil decreases,and the liquid-plastic limit of fulvic acid soil and potassium humus soil shows an upward trend.When the curing age is fixed,with the content of organic matter increases,the agglomeration of soil particles,the porosity of soil and the compressibility of soil increase.When the content of organic matter is constant,the soil compressibility ranking is fulvic acid soil>potassium humate soil>humate soil,and the compressibility of organic soil with high initial water content is always greater than that of soil with low initial water content.The soil compressibility is closely related to the type and content of organic matter.The research results can provide reference for the subsequent improvement of organic soil,calculation of foundation settlement and evaluation of its stability.