Apparatus induced error in hydraulic conductivity measurement using a Lucite® fixed wall permeameter

Hydraulic conductivity is the most variable parameter in geotechnical engineering. Although accurate measurement of hydraulic conductivity of fine-grained soil is not an easy task, it is often required to satisfy the legitimate requirements of various agencies regulating the design, construction, and operation of compacted clay liners. Results are sensitive to the experimental apparatus and testing procedure used for the measurement. As the flow volumes being measured are very small, any minute leakage of permeant during the test will significantly affect the results obtained. The quantification of a significant unexpected loss of permeant through fixed wall permeameters made of Lucite is documented and discussed in this paper.