Analyzing filtration flow rate change of woven geotextiles for fine grained slurries

Many studies have been performed in recent years to investigate the dewatering phenomena of slurry using geotextile tubes. The laboratory test methods primarily used the pressure filtration test (PFT) and falling head test (FHT) to evaluate the dewatering nature of geotextiles using slurries with different fines contents. The objective of this paper is to examine and analyze the published test data obtained from various testing conditions, and to develop a general equation that can predict the change of flow rate over time. For the PFT, a power law showed a good fit with test data at different fines content ranges. Furthermore, the change of filtration rate with time decreased with the fines content, indicating that slurry with high fines content resulted in a faster drop in filtration rate than slurry with low fines content. For the FHT, a two-term power law was found to fit all of the test data, indicating a two-stage filtration behavior.