不同粒径级砂土渗透特性试验研究

发布时间：2019-08-11 13:38

【摘要】：渗透性是砂土的重要工程性质之一,影响砂土渗透性的因素有很多,比如土体密实程度、土颗粒自身特性、流体性质等,其中孔隙率与颗粒粒径是两个重要影响因素。而以往基于混合粒径的天然砂土的研究很难分别对这两个因素进行独立的研究。基于此,首先开展了单一粒径级砂土的常水头渗透试验,分别研究了同一粒径级砂土渗透系数随孔隙率的变化和同一孔隙率下不同粒径级砂土渗透系数随均值粒径的变化规律。试验结果显示,渗透系数随着孔隙率的增加而线性增加、随均值粒径二次方的增加而线性增加,其中均值粒径的影响较大,其变化能导致渗透系数量级上的差异。在此基础上,开展了多粒径混合砂土的渗透试验,讨论了曲率系数、不均匀系数等级配参数对渗透性的影响,从而将单一粒径级的研究成果推广到天然砂土,最终拟合出渗透系数与相关影响因素的经验公式,以便工程实践参考使用。
[Abstract]:Permeability is one of the important engineering properties of sand. There are many factors that affect the permeability of sand, such as the degree of soil compactness, the characteristics of soil particles themselves, the fluid properties and so on, in which porosity and particle size are two important influencing factors. In the past, it is difficult to study these two factors independently in the study of natural sand based on mixed particle size. Based on this, the constant head permeability test of single grain size sand was carried out, and the variation of permeability coefficient with porosity and the variation of permeability coefficient with mean particle size under the same porosity were studied respectively. The experimental results show that the permeability coefficient increases linearly with the increase of porosity and linearly with the increase of mean particle size quadratic power, and the influence of mean particle size is greater, which can lead to the difference of permeability coefficient in the order of magnitude. On this basis, the permeability test of multi-particle size mixed sand is carried out, and the influence of curvature coefficient and uneven coefficient grade parameters on permeability is discussed, so that the research results of single grain size grade are extended to natural sand, and finally the empirical formula of permeability coefficient and related influencing factors is fitted, which can be used as a reference for engineering practice.
【作者单位】：西安建筑科技大学西部建筑科技国家重点实验室(筹);中国科学院水利部成都山地灾害与环境研究所中国科学院山地灾害与地表过程重点实验室;浙江精工钢结构集团有限公司;
【基金】：国家自然科学基金项目资助(No.51278397) 中科院重点部署项目资助(No.KZZD-EW-05-01)
【分类号】：TU441

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