Author:

Keywords:

embankment, sludge, soft soils, Science & Technology, Technology, Physical Sciences, Engineering, Civil, Engineering, Geological, Mathematics, Applied, Engineering, Mathematics

Abstract:

The behavior of an industrial sludge, arising from fertilizer and feed phosphate production, has been found to be similar to that of clayey soil. Prior to its use as a construction material for an embankment, the soft sludge has been improved by means of a filter press chamber to reduce the water content and, thereby, to obtain a stiffer material. Filter pressing has yielded relatively stiffer sludge filter cakes with a water content of less than 90%. Extensive laboratory tests have been conducted in order to characterize the uncertain behavior of the original sludge and the filter cakes. Under drying and re-wetting cycles, the filter cakes loose their strength after 4 days of rewetting due to the structure damage. Variation of compression state as well as uncertain behavior of the sludge has necessitated greater attention to the deformation of the foundation. Finite element simulations have been performed giving quite reasonable predictions.