摘要
通过饱和渗透性结合土水特性曲线可以预测土在非饱和状态下的渗透性,饱和渗透性一般通过渗透性试验得到。岩土工程中需要判断不同土质在非饱和状态下的渗透性,如果都通过试验获得,将会费时费力。与饱和渗透性相比,导气率的测量是简单的,通过导气率预测饱和渗透性显然更有效率。Loll和Moldrup等人对田间土壤进行了试验,发现导气率和饱和渗透性之间存在对数线性关系,提出并通过导气率预测了饱和渗透性。由于对数线性关系中的参数受土质影响很大,没有统一的公式。在前人研究基础上,试验对粉质黏土进行了研究。粉质黏土的渗水和渗气均存在一个起始压力,超过起始压力后,导气率随入渗气压力呈线性关系;饱和渗透性和导气率呈对数线性关系;干土状态下的导气率比饱和渗透性大2～3个数量级。得到的结论可为在粉质黏土中利用导气率预测饱和渗透性提供指导。
Saturated hydraulic conductivity is commonly conductivity under unsaturated conditions on the basis used in the predictive relationships for the hydraulic of the water retention characteristics. Usually, the parameter Kw is obtained through permeability tests. In geotechnical engineering, the unsaturated hydraulic conductivity in different soil conditions is needed. It is often time-consuming if all parameters are gained from tests. The measurement of gas conductivity is rather simple compared with the saturated permeability and it is obviously more efficient to predict the saturated permeability. Loll and Moldrup found the log-log linear relationship between the gas conductivity and the saturated conductivity, and predicted the saturated conductivity through the gas conductivity based on their field soil tests. As the parameters in the log-log linear relationship are greatly influenced by soil texture, there is not a uniform formula. Based on the previous studies, the experiment on the silty clay is conducted, and the conclusion can be used to provide guidance for the prediction of the saturated permeability in the silty clay. The main conclusions are as follows ： （ 1 ） there is a starting pressure of the water seepage and after the initial pressure, the gas permeability in the silty clay is linearly related to the gas pressure; （2） the saturated permeability and the gas conductivity show a logarithmic linear relationship ; （3） the gas conductivity of dry soil is 2 to 3 orders of magnitude greater than the saturated permeability.
作者
钱文见
尚岳全
朱森俊
陈晓辉
QIAN Wenjian SHANG Yuequan ZHU Senjun CHEN Xiaohui(College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310058, China Department of Ocean Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China)
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2016年第5期94-99,104,共7页
Hydrogeology & Engineering Geology
基金
国家自然科学基金资助项目(41372277)
"十二五"国家科技支撑计划(2012BAK10B06)
关键词
粉质黏土
渗透性
导气率
模型试验
silty clay
permeability
gas conductivity
model test
