Effect of the Geosynthetic Installation on the Compaction Curve and Compaction Efficiency

Compaction is performed to avoid ground settlement during backfilling or embankment construction. In this study, Proctor compaction tests according to KS F 2312 were performed by installing geosynthetics (with and without geosynthetics) and changing the compaction type (A and D), type of geosynthetics (geogrid and polyester (PET) mat), number of reinforced geosynthetic layers (1-4 layers), and number of blows per layer (55, 50, 45, and 40). Using a geogrid (or PET mat) reduced the optimum water content (ω opt ) by 7.5% (8.3% for PET mat) and 12.7% (8.2% for PET mat) and increased the maximum dry density (γ dmax ) by 3.9% (4.2% for PET mat) and 5.5% (4.8% for PET mat) for compaction test types A and D, respectively. In compaction without geosynthetics, the required compaction energy increased by 1.35 and 1.27 times compared to the value to achieve the identical γ dmax with 4 geosynthetic layers for the geogrid and PET mat, respectively. Thus, efficient compaction is possible by decreasing the compaction energy required to achieve the target dry density with geosynthetic installation. The effect of geosynthetics during compaction to improve the compaction degree has also been proven with a field test.