GEOTEXTILE TUBE: FILTRATION PERFORMANCE OF WOVEN GEOTEXTILES UNDER PRESSURE

Geotextile tubes are manufactured by sewing one or more layers of high-strength permeable woven/non-woven geotextiles together to form tubes that are later filled with high-water content materials by hydraulic pumping. Recently, Moo-Young et al. (2002), Kutay (2002), and Aydilek and Edil (2002), have conducted laboratory studies which concluded that the apparent opening size (AOS1) alone is not a good indicator to predict the filtration behavior of geotextile tubes. Therefore, the current filtration criteria based on apparent opening size do not apply for geotextile tubes. When geotextile tubes are used in dewatering slurries, a filer cake forms on the interface of the soil and geotextile. The formation of the filter cake, which leads to the retention of the soil particles, can be controlled by the pore openings of the geotextile, the particle size distribution of the soil, the water content of slurry, and the pumping pressure. The purpose of this paper is to study the effect of the large-pore openings of geotextiles on the filtration performance of geotextile materials. In this paper, filtration behavior of three woven geotextiles is studied using the pressure filtration tests on three natural soil sediments. Results are presented on the influence of the water content, pressure, and polymer