Abstract: Disadvantages existed in using the conventional seepage device for the measurement of the permeability of soilcement mixed soils, this paper presents an improved flexible wall permeameter utilizing the double drainage lines for the measurement of the hydraulic conductivity of soilcement mixed samples. A rubber membrane is introduced to wrap the side of the specimen and side seepage can be avoided under the confining water pressure. Four drainage lines are used to facilitate the sample saturation and eliminate the air bubbles in the sample. The improved device was used to measure the permeability of the soilcement mixed samples in an estuary reservoir project in Yangtze River under four different hydraulic gradients. The relationships between the seepage rate and the hydraulic gradient were obtained. The results indicate that the seepage within the tested soilcement soil samples is laminar flow following Darcy’s law. This improved device can also be used in simulating the insitu seepage conditions.

Key words: Hydraulic Conductivity, Double Drainage Line, Flexible Wall Permeameter, Soil-Cement Mixed Samples, Seepage Rate, Hydraulic Gradient, Confining Pressures