马兰黄土渗气率与饱和渗透系数的关系研究

发布时间：2018-11-13 10:40

【摘要】：利用改进的ZC-2015型渗气仪和TST-55型渗透仪进行马兰黄土渗气和饱和渗透试验,确定稳定渗气率对应的稳定渗径,进而探讨渗气率ka和饱和渗透系数Kw的关系。研究结果表明:ka不仅能描述非饱和土孔隙和结构特征,也能用于预测Kw。气体渗气率随着渗径的增大而减小,最终趋于稳定,原状和重塑黄土的稳定渗径均约8 cm。ka和Kw间呈明显的双对数线性关系,不同深度的原状风干黄土和不同粒组的重塑土的lgka和lg Kw间的相关性都比较明显,但原状风干黄土和重塑土之间的拟合公式有很大差异。另外,黏粒含量较高时,重塑土拟合直线的斜率β和截距α明显增大。不同含水率下,重塑土拟合公式有很大的差异,当含水率较大时,随着干密度的增大,ka的变化程度比Kw大,拟合直线的斜率β和截距α都有明显的减小。
[Abstract]:In this paper, the modified ZC-2015 and TST-55 permeability instruments are used to test the permeability and saturation permeability of Ma Lan loess. The steady permeability diameter corresponding to the steady permeability ratio is determined, and the relationship between the permeability ka and the saturated permeability coefficient Kw is discussed. The results show that ka can not only describe the pore and structure characteristics of unsaturated soil, but also can be used to predict Kw.. The gas permeation rate decreases with the increase of the permeability diameter, and eventually tends to be stable. There is an obvious logarithmic linear relationship between the stable permeability diameter of both undisturbed loess and remolded loess about 8 cm.ka and Kw. The correlation between lgka and lg Kw of undisturbed air-dried loess with different depth and remolded soil with different grain groups is obvious, but the fitting formula between undisturbed air-dried loess and remolded soil is very different. In addition, when the clay content is high, the slope 尾 and intercept 伪 of the remolded soil are increased obviously. Under different water content, the fitting formula of remolded soil is very different. With the increase of dry density, the change degree of ka is larger than that of Kw, and the slope 尾 and intercept 伪 of fitting straight line decrease obviously.
【作者单位】：长安大学地质工程与测绘学院;国土资源部岩土工程开放研究实验室;
【基金】：国家自然科学基金资助项目(41572264,41172255,41440044)
【分类号】：TU444

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