Study of a testing method for permeability of unsaturated soil with applied air pressure

非饱和土气压渗透性测试方法研究

• 批准号: 62850093
• 负责人: UNO Takao
• 金额: $ 1.66万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1988
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-62850093/
• 关键词: Unsaturated soil; Coefficient of permeability; Suction; Degree of saturation; Filter; 間隙空気圧

Testing method for permeability through unsaturated sands were examined in consideration of three measuring ways of saturation. On the other hand, behaviors of pore air/water in soil were analyzed by the use of FDM program for the multi-phase flow. It was found that the degree of saturation under confined air pressure was inclined to be uniquely distributed within sand column, which was also confirmed in experiment.Considering this properties of the mix fluids and reforming the permeability test apparatus in the applying air pressure type, for example,combining the two burette to measure seepage quantity, we performed permeability tests of unsaturated sand and silt in this last fiscal year, and obtained some concrete testing guides as follows.(1) As for the necessary filter abjacent to soils, the effect of correction of its resistance against seepage on permeability is evaluated with selection of its material.(2) Unique distribution of water content in soil and appropriate applied hydrauric gradient of 1.0-3.0 is recognized in the experiments.(3) High quality of measuring system of seepage quantity by two burette results in the continuous measuring way of the relation between permeabilty and degree of saturation, in comparison with the previously proposed methods for estimating permeability of unsaturated soils.

针对三种饱和度测定方法，对非饱和砂土渗透系数的测试方法进行了研究。另一方面，利用多相流的有限差分程序，分析了土壤中孔隙气/水的行为。研究发现，在封闭空气压力作用下，饱和度在砂柱中呈单一分布，这一点在实验中也得到了证实，针对混合流体的这一特性，对加压式渗透试验装置进行了改造，如将两个测渗量的滴定管结合起来，进行了非饱和砂和粉土的渗透试验，并得到了一些具体的测试指南如下。(1)对于与土壤隔离的必要反滤层，通过反滤层材料的选择，评价了反滤层抗渗性对渗透性的修正效果。(2)试验结果表明，土壤含水量具有独特的分布规律，适宜的水力梯度为1.0-3.0。(3)与以往提出的非饱和土渗透系数的估算方法相比，双滴定管渗量测量系统的高质量，使渗透系数与饱和度关系的连续测量成为可能。

项目成果

宇野尚雄: 第24回土質工学研究発表会概要集. (1989)

Nao Uno：第24届土壤工程研究会议摘要集（1989）。

佐藤健: 土木学会中部支部昭和63年度研究発表会概要集. (1989)

Ken Sato：日本土木工程师学会中部分会 1985 年研究报告摘要集（1989 年）。

Uno, Takao: "Quicksand of sandy soils due to air flow," The 23rd Japan National Conf. on SMFE.,. 2/2. 1859-1860 (1988)

宇野高尾：“气流导致沙土流沙”，第 23 届日本全国会议

宇野尚雄: 土木学会論文集.

Nao Uno：日本土木工程师学会会议录。

Uno, Takao: "Transient flow of soil water due to air pressure," The 23rd Japan National Conf. on SMFE.,. 2/2. 1861-1862 (1988)

宇野高雄：“气压引起的土壤水的瞬时流动”，第 23 届日本全国会议。