非饱和土土水特性曲线与渗透系数试验研究

发布时间：2018-01-08 02:21

本文关键词：非饱和土土水特性曲线与渗透系数试验研究　出处：《大连理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：现有的土力学理论体系中,大部分理论都是在假设土体为饱和土的基础上建立的,即认为土只由土骨架和孔隙水组成。而在实际工程中所接触的土,大部分为三相土,即除土骨架和孔隙水之外,还有气相的存在。这样的土被称为非饱和土。针对非饱和土的各方面特性的研究是目前岩土工程学界的一个重要课题。本文在前人已有的理论成果的基础上,对非饱和土的渗流特性进行了试验研究。土水特性曲线与渗透系数是非饱和土渗流研究当中非常重要的内容。本文对土水特性曲线与渗透系数的意义、特性与应用进行了介绍,并总结了前人获取非饱和土土水特性曲线与渗透系数的试验及理论方法。在此基础上,本文应用大连理工大学岩土与环境力学实验室自主研发的非饱和土土水特性曲线与渗透系数联合测量仪,对非饱和黄土与硅微粉的渗透特性进行了试验研究,并得到相应的土水特性曲线与渗透系数。根据试验结果对土水特性曲线进行了VG模型拟合,阐述了非饱和土的渗透系数与基质吸力以及土体饱和度之间的变化关系。通过对比两种土的试验结果,结合其各自基本物理特性,尤其是颗粒组成情况,讨论了粒径不同对渗透特性的影响。本文还从孔隙水的平衡方程出发,结合非饱和土中土水间相互作用力理论,对非饱和土中孔隙水渗流运动方程与渗透系数的理论公式进行了推导。并根据渗透试验研究的数据结果对非饱和土渗透系数的理论公式进行了验证,确定了其合理性。
[Abstract]:In the existing soil mechanics theory system, most of the theories are based on the assumption that the soil is saturated soil, that is, the soil is only composed of soil skeleton and pore water. Most of them are three-phase soil, that is, except soil skeleton and pore water. There is also the existence of gas phase. Such soil is called unsaturated soil. The study of various characteristics of unsaturated soil is an important subject in geotechnical engineering. This paper is based on the previous theoretical results. The seepage characteristics of unsaturated soil are studied experimentally. Soil-water characteristic curve and permeability coefficient are very important in the study of unsaturated soil seepage. The significance, characteristics and application of soil-water characteristic curve and permeability coefficient are introduced in this paper. The experimental and theoretical methods for obtaining the characteristic curve and permeability coefficient of unsaturated soil were summarized. In this paper, the permeation characteristics of unsaturated loess and silicon powder were studied by using the instrument of unsaturated soil water characteristic curve and permeability coefficient developed by the laboratory of geotechnical and environmental mechanics of Dalian University of Technology. The corresponding soil-water characteristic curve and permeability coefficient were obtained. According to the test results, the soil-water characteristic curve was fitted by VG model. The relationship between the permeability coefficient of unsaturated soil and the matrix suction and the saturation of soil is expounded. By comparing the experimental results of the two soils and combining their respective basic physical characteristics, especially the particle composition. The influence of particle size on permeability was discussed. Based on the equilibrium equation of pore water and the theory of interaction between soil and water in unsaturated soil, this paper also discusses the relationship between soil and water. The equation of porous water seepage and the theoretical formula of permeability coefficient in unsaturated soil are deduced, and the theoretical formula of permeability coefficient of unsaturated soil is verified according to the data of permeation test. The rationality is determined.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU43

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