A tracer method to determine hydraulic conductivity and effective porosity of saturated clays under low gradients

Yi Jang Yeh, Cheng Haw Lee, Shih Tsu Chen

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

Based on the column tracer test, we developed a research method to determine the hydraulic conductivity and effective porosity of saturated clays under low hydraulic gradients or small flow rates. Derived from Darcy's law and the solute transport equation, this method evaluates the hydraulic conductivity through measuring solute concentrations rather than by measuring flow rates. And the effective porosity is determined by applying an analytical solution of the one-dimensional uniform flow equation. Two types of experimental data drawn from a review of the literature and four sorts of accuracy test data carried out in the laboratory are used to examine the proposed method. The reproducibilities of accuracy tests for hydraulic conductivity determination indicate a consistency within a 5.5% error margin. The experimental results further indicate that hydraulic conductivities determined using the tracer method are more precise than those from the conventional flowmeter method. In addition, with the assistance of the proposed tracer method, we argue that the effective porosities may be overestimated as shown in the drawn example cases due to mistaking total pore volumes as the effective pores. The results of the accuracy tests further indicate that the effective porosities of saturated clay specimens are significantly smaller than the total porosities, at least when the samples are allowed to swell freely.

Original languageEnglish
Pages (from-to)522-529
Number of pages8
JournalGround Water
Volume38
Issue number4
DOIs
Publication statusPublished - 2000

All Science Journal Classification (ASJC) codes

  • Water Science and Technology
  • Computers in Earth Sciences

Fingerprint Dive into the research topics of 'A tracer method to determine hydraulic conductivity and effective porosity of saturated clays under low gradients'. Together they form a unique fingerprint.

Cite this