EXPERIMENTAL STUDY OF AN EMBANKMENT OVER A SOFT SOIL LAYER USING CLAY-FLY ASH-EPS MIXTURES AS A LIGHTWEIGHT FILL MATERIAL

Abstract

The use of lightweight fill materials as highway embankment can reduce the total settlement of soft subsoil is one method of design improvement by reducing the weight of the embankment itself. The lightweight fill material used in this research is a mixture of clay, fly ash, and expanded polystyrene or EPS. The objective of this experimental test was to see how lightweight fill material affected the displacement that occurred in the soft subsoil layer. Three models with a scale of 1/10 were constructed using a mixture of clay, 25% fly ash, and variations of EPS content in each model, which were 0% (TR-00), 0.2% (TR-02), and 0.4% (TR-04) respectively. The TR-00 model shows higher stiffness than the TR-02 and TR-04 models according to experimental test results. At a displacement of 2.54 mm, the stiffness of the TR-02 and TR-04 models is reduced by 9.8% and 21.8%, respectively, compared to the TR-00 model. The overall displacement experienced by the TR-02 and TR-04 models, on the other hand, is less than that of the TR-00 model. The TR-04 specimen has the highest performance among other specimens with the lowest displacement while still having satisfactory stiffness.