Improvement the properties of geogrid encased stone columns by grouting

Stone columns, which are one of the soil improvement methods, have been used to enhance the bearing capacity of saturated clayey soils, to increase permeability, to reduce settlement levels and to accelerate the consolidation process. Nowadays, confinement effect is featured by the geosynthetic materials that have been encased around the outer surface in order to improve the performance of stone columns. In this thesis, water-cement grouting was applied to geogrid encased stone columns and its effect on bearing capacity was investigated. Within this purpose, cylindrical shaped stone columns were produced via 2 types of granular backfill, 2 different water/cement ratios and 2 types of geogrids. the specimens were subjected to compression tests and stress-strain behavior along both axial and lateral directions were examined compared to the reference samples, after 28 days with the hardening of concrete. It is planned to provide an economical and an effective application possibility thank to the producing of a unique composite structure with injection inside geogrid encased stone columns.