A Methodology for the Evaluation of Geotextile Pore Opening Sizes Under Confining Pressure Available to Purchase

This paper presents a methodology used to evaluate the pore opening sizes of a needle-punched, nonwoven polyester geotextile under pressure, using a permeameter subject to vibration. Particles passing through the geotextiles were collected and analysed to establish a particle size distribution curve. Preliminary results obtained under no confining pressure compare well with a standard test method based on hydrodynamic sieving. Confining pressures up to 25 kPa appeared to exert some influence on the pore opening size of relatively thin geotextiles. However, for pressures greater than 25 kPa, the variation of geotextile pore opening size is small. The tests results and microscopic observations suggest that needle-punching during the geotextile manufacturing process has a significant influence on the geotextile pore structure. Regardless of the limited amount of data available, the methodology described may provide a useful tool for the study of geotextile pore opening sizes under confining pressure.