Evaluation of geotextile/soil filtration characteristics using the hydraulic conductivity ratio analysis

Abstract

The evaluation of the flow properties and filtration characteristics of geotextiles used in conjunction with soils is a complex problem encountered in many engineered systems. This paper examines changes in the hydraulic conductivity of geotextile/soil composites resulting from permeation of water under controlled conditions. The evaluation of the filtration characteristics of the geotextile/soil composite was performed using both natural and prepared soil specimens. The prepared soil specimens were composed of clean, uniform sand and pure, nonplastic silt. The analyses were performed in a modified triaxial permeability device so that the state of stress, stress history, void ratio, drainage path, soil structure and other variables affecting the hydraulic conductivity could be measured or controlled. The hydraulic conductivities of several combinations of geotextiles and soils were measured. The hydraulic conductivity ratio, or ratio of the hydraulic conductivity of the soil/geotextile composite to that of the soil, was computed for each specimen.