Determining Fluid Compressibility and Soil Permeability of Quasi Saturated Sand with the Alternating Flow Apparatus

Predicting pore water pressures due to wave induced pressure fluctuations on quasi saturated porous beds is important e.g. for the design of bank protections in channels. Therefore, the influence of fluid compressibility and the coefficient of permeability both depending on the degree of saturation were analyzed by means of laboratory testing with the alternating flow apparatus of the Federal Waterways Engineering and Research Institute. A methodology for the determination of the saturation dependent parameters based on high precision pressure and discharge measurements is presented. As shown in the present paper, test results and finite element simulations based on the determined parameters coincide very well.