The geotextile filtration of fine particles in suspension in water, or of clayey sludge, is more complex than the filtration of granular soils in suspension; in practice in such application, floccu-lants are generally used to postpone the apparition of the filter cake. The present study, realized without flocculent, has been established to determine the influence of the geotextile characteristics on the for-mation of the filter cake. The role of key parameters, like the type of soil, the concentration of fines, the type of water flow and the type of geotextile is analysed and discussed in detail. The performance of the different systems is compared based on the analysis of the retained and passing soils, the time for clog-ging and the global characteristic of the filter cake. The settling of the fines in the testing device and its influence on the results is also analysed. The different cake’s formation processes, the different particle sizes distributions and the different specific cake resistances are evaluated, analysed and discussed. As the permeability of the system changes with the creation of the filter cake, the initial permeability of the geo-textile is less important than the influence of the geotextile on the creation process of the filter cake and its characteristics. The obtained results and comparisons are reasonably good. This study allows showing for the soils tested, that geotextiles with specific properties allow reaching a best compromise between the opening size and the support of a filter cake suitable for the long-term permeability.
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