Geotextile tubes are excellent design strategies for both shoreline protection and dewatering of fine materials. A difficulty with regard to designing geotextile tubes is the matching of the appropriate fabric with the site-specific infilled material and the unavailability of a test to determine the soil-geotextile consolidation properties. Existing methods simulate and predict the final tube shape based on the initial and final unit weights of the infill but the time required to reach the final shape or the compatibility of the infill are not being considered. This study proposes an improved hanging bag test to evaluate the compatibility of an infill with the geotextile fabric, and at the same time, to obtain the soil-geotextile consolidation properties. With the obtained consolidation properties, a big prototype simulation was possible, explaining the deformation behavior of the tube in the field. An analytical procedure used in modeling the tube was coupled with the large strain consolidation theory to simulate the filling and dewatering process.

Coal Ash, a byproduct of coal combustion in power plants, is usually disposed in surface impoundments or wet disposal areas and landfill sites. Toxic substances contained in coal ash which slowly seep into the groundwater and aquifers in nearby impoundments, and which are also dispersed by wind and storm water in landfill sites, lead to serious health and environmental effects. The main focus of this study is to analyze the strength characteristics of the recycled coal ash mixed with dredged soil to test its capabilities from external forces such as in the stacking of geotextile tubes. The SEM and XRF analysis were carried out in order to grasp the grain size and composition of the coal ash and the dredged soil. To find the optimum mixing ratio of the coal ash and dredge soil, the type of deformation and the strength of the different mixtures were obtained by performing a uniaxial compression test. The relationship between the compressive stress and deformation of the uniaxial compression test and the tubular structure formed by injecting the coal ash into geotextile tube was confirmed and the applicability of the geotextile tube reinforced with the recycled and improved fill material is very high.