饱和砂性土孔隙水电导率特性及测试技术

Electrical conductivity of pore water in saturated sand and its measurement technology

饱和砂性土的孔隙水电导率直接反映了孔隙水中离子的含量,对研究土体离子污染有重要意义。饱和砂性土中孔隙水电导率与土体电导率之间呈线性关系,符合Archie定律。研究了Archie定律在不同类型砂土中的m系数取值范围,提出了利用TDR测试技术监测饱和砂性土孔隙水电导率的方法。试验结果表明TDR能够很好地测得饱和砂性土的孔隙水电导率。研究成果对于土体中离子污染物监测有重要的应用价值。

It is of great significance to the study of ionic contamination that the electrical conductivity of pore fluid in saturated sandy soil reflects the ion content.The electrical conductivity of pore fluid in saturated sandy soil has a perfect linear relationship with the bulk electrical conductivity of the soil,which confirms the Archie’s law.The values of the exponent,m,in Archie’s law for saturated sandy soils are obtained,and a new method is developed based on the use of TDR technology to monitor the change of the electrical conductivity of pore fluid in saturated sandy soil.The experimental results show that TDR is able to provide a reasonably accurate estimation of the electrical conductivity of the pore water.It is of great importance to monitor the ionic contamination in saturated sandy soils in situ.