Testing and analytical modeling of two-dimensional geotextile tube dewatering process

Abstract

Geotextile tubes are used to dewater slurries, sediments, and wastes. With their extensive use for dewatering, the desire to maximize both dewatering rate and sediment retention has led to the use of chemical accelerants, which have become a standard practice in geotextile tube dewatering projects. A variety of test methods are currently used to evaluate geotextile tube performance, ranging from small-scale Falling Head Tests (FHTs), medium-scale Hanging Bag Tests (HBTs), and Geotextile-tube Demonstration Tests (GDTs), to full-scale pilot tests. However, few studies have compared the results from different dewatering tests and fewer have developed proper correlations between test methods. In this study, a recently developed pressurized two-dimensional dewatering test (P2DT) is used to analyze the dewatering process in geotextile tubes in both the radial and axial directions. In this study, P2DT and GDT tests were performed on Tully slurry at different solids concentrations conditioned with chemical accelerants and under different pressures. The P2DT results, along with analytical modeling, are then used to predict the dewatering behavior of GDTs based on P2DT, where the predictions were within 8%. Based on the results, a framework for predicting the dewatering behavior of full-scale tests using an analytical model generated from P2DT is presented.