Study on the remediation of contaminated fine-grained soils based on the effect of permeability increase by freeze-thaw method

基于冻融增透效应的污染细粒土修复研究

基本信息

批准号：
16560438
负责人：
ITO Yuzuru
金额：
$ 2.24万
依托单位：
Setsunan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16560438/
关键词：
contaminated soils permeability freeze-thaw frost heave

项目摘要

The purpose of this study is to clarify the influence of freeze-thaw effect on increase in permeability of fine-grained soils. With sample soils such as Fujimori clay and Kanto loam, the influence of freeze method, overburden pressure, difference of soils, water supply condition and so on is examined. As a result, the followings findings were obtained ;1)It is considered from the experiments that the influence of frost heave is very small for increase in permeability after freeze-thaw treatment. In other words, there is no relationship between the degree of permeability increase and such conditions as temperature descent speed, temperature gradient, freezing speed and or water supply condition.2)Besides the properties of soil, it was cooling temperature and overburden pressure that affected the permeability increase after freeze-thaw treatment. As for the cooling temperature, there is no further effect if the temperature around -5 to -7 ℃ is adopted to freeze the soils. As for the overburden pressure, the method might be effective at least to the depth of 10 to 20 meter below the ground surface.3)It is considered that the reason of permeability increase is something related to a change of soil surface. Because there is a difference in an unconfined strength of remolded soils of the freeze-thaw treated specimen and untreated one. In addition, there was a similarity between the permeability freeze-thaw treated soils and oven-dried ones.

这项研究的目的是阐明冻融效应对细粒土壤渗透性增加的影响。随着样品土壤（例如藤木粘土和关东壤土）的影响，冻结方法的影响，覆盖压力，土壤差异，供水状况等。结果，获得了以下发现； 1）从实验中考虑到霜冻的影响非常小，对于冻融治疗后的渗透性增加。换句话说，渗透率的增加程度与温度下降速度，温度梯度，冷冻速度和 /或供水状态等条件之间没有关系。2）除了土壤的特性外，冷却温度和过度压力都会影响冻结治疗后的渗透率增加。至于冷却温度，如果采用-5至-7℃的温度来冻结土壤，则没有进一步的影响。至于覆盖压力，该方法至少可以有效至地面以下10到20米的深度。3）认为，渗透性增加的原因与土壤表面变化有关。因为冻结治疗的标本和未经处理的标本的重新倒入土壤的无限强度存在差异。此外，渗透性冻结处理的相似性。土壤和烤箱干燥的土壤。