Testing procedures to assess the viability of dewatering with geotextile tubes

Geotextile tubes are finding increasing market acceptance for dewatering high water content materials. The success of this application depends on the filtration compatibility between the high water content materials and the geotextiles used to make the tubes. In this paper, 26 pressure filtration tests using four woven geotextiles of various materials were conducted to study soil retention and permeability of the sludge/geotextile system and the possible controlling factors. Based on the test results, the filter cake is not only the major contributor to the retention of fine particles, but also causes a decrease in permeability. Controlling the formation of the filter cake on the inside of the geotextiles tube and thus achieving a balance between soil retention and permeability is vital to a successful project. Surprisingly, initial water content may have a significant effect on the dewatering efficiency and dewatering rate. More testing is recommended to gain a deeper understanding into this relationship. (C) 2002 Elsevier Science Ltd. All rights reserved.