Volume 28, Issue 6 (November 2005)
Comparison of Geotechnical Engineering Consolidation and Physical Science Filtration Testing Techniques for Soils and Suspensions
Traditionally, there have been two approaches to the modelling and prediction of the extent and rate of dewatering of particulate networks: consolidation theory and filtration theory, developed by geotechnical engineers and physical scientists, respectively. The physical situations and governing equations for Terzaghi's consolidation model (Terzaghi and Peck 1967) and Landman and White's filtration model (Landman and White 1997) are essentially the same. However, their methods of determining the relative dewatering parameters differ. The consolidation method matches experimental data from oedometer testing to the theoretical predictions of the model in order to determine the coefficient of consolidation, cv. The filtration method determines a solids diffusivity coefficient, D, based upon the experimental data from a filtration rig, which is then used in modelling to make predictions.
This work aims to highlight the similarities between the two approaches, initially by demonstrating the theoretical relationship between the two parameters, cv and D, and then through experimental determination. The material characteristics of a kaolin sample undergoing one-dimensional (zero lateral strain) compression are determined using both oedometer and filtration testing and equated using the developed theoretical relationship. The results indicate that the two testing methods are essentially the same, and that their relevant analysis techniques give similar outcomes. Consequently, geotechnical engineers can use filtration methods and physical scientists can use consolidation methods.