有机质和黏土矿物对软土流变性质影响的对比试验研究

Comparative Experimental Investigation into Effects of Organic Matter and Clayey Mineral on Rheological Properties of Soft Soil

采用改进的直剪蠕变仪,在相同试验条件下测试了两组分别含相同质量分数有机质及膨润土的软土试样的流变性质.结果表明,有机质和膨润土是影响软土流变性质的重要因素,且有机质对软土流变性质的影响较膨润土的显著.试验结果分析认为,有机质和膨润土所含蒙脱石通过吸附于颗粒表面的结合水影响土的流变性质,其中强结合水是土体产生流变的主要因素,而弱结合水则是相对次要因素.试验结果有助于进一步认清土体流变的起因,对改进和完善现有流变变形计算理论有一定指导意义.

An improved direct shear creep apparatus was used to test the rheological properties of two soft soil samples respectively containing organic matter and bentonite with the same content in the same test conditions. The results show that （ 1 ） organic matter and bentonite are two important factors affecting the rheological properties of soft soil, especially the former; （2） the effects of organic matter and bentonite on the rheological properties of soft soil are due to the bound water adsorbed by montmorillonite on the soil particle surface; and （3） the firmly-bound water is the primary factor and the loosely-bound water is the secondary factor to induce the rheological properties. The test results help to reveal the emerging causes of soil rheology and to improve the existing calculation theories of rheology deformation of soft soil.