A Comparison of Test Methods Adopted for Assessing Geotextile Tube Dewatering Performance

摘要

Geotextile tubes have successfully been used by virtually every industry todayto dewater a variety of sediments, slurries, by-products, and wastes. Despite this, thedewatering industry currently lacks uniformity in regards to establishing testingstandards and assessing dewatering performance. Prior to full-scale tube deployment,lab and/or field tests are typically performed to evaluate performance. Preliminarybench tests such as the falling head test (FHT) and pressure filtration test (PFT) areoften used to evaluate candidate polymers and dewatering efficiency. The mid-scalehanging bag test (HBT) and geotextile tube dewatering test (GDT) may then be usedto visualize the dewatering process and evaluate the selected polymer. There iscurrently no industry standard, however, and numerous variations in testingprograms, methods, and data interpretation exist. Before advanced studies can beundertaken, a common framework for data interpretation must be created bystandardizing testing programs. Using a fine grained, non-plastic soil and wovengeotextiles, this study aims to examine and compare the bench-scale and mid-scaletest methods adopted for assessing dewatering performance. In addition tostandardized testing programs, the need exists for estimating geotextile tubedewatering rates. This study proposes a theoretical model using Darcy’s law and theKozeny-Carman equation which allows for an estimation of dewatering time.