ABSTRACT
Application of centrifuge modelling for studying flow through soils is complex because the seepage velocity scales proportional to centrifuge gravity, resulting in greater potential for exceeding Darcy’s flow conditions. Research efforts have been done to determine laminar flow limit based on Forchheimer’s principles and the concept of critical Reynolds Number (R critic ). However, the interpretation of this limit remains ambiguous. This study provides new insights and establishes a connection between two different theoretical approaches. Centrifuge permeability tests were conducted at different gravitational levels for different gradation of silica sands. Results show that parameters of Forchheimer’s regime remain constant regardless of the centrifuge gravity. Values of R critic were found to be smaller than 1 for the finest sand, and between 3 and 10 for the coarser sands. These results indicate that reference values of R critic are inaccurate for fine sands and very conservative for coarse sands.
