Experimental evaluation of compressibility parameters of lime and silica fume stabilized dredged soil

Abstract

The use of alternative materials in civil engineering applications contributes to sustainable development and the economy. Large amounts of sediment are produced as waste material regarding to dredging activities in canals and ports. Storage or disposal of this material may cause some environmental and economic problems. To overcome these problems, dredged soils can be used for various civil engineering applications such as filling materials of road, foundation, and embankment. However, dredged soils generally have low bearing capacity, shear strength, and high compressibility due to their organic matter content. Therefore, these soils need to be improved with various additives before using as fillers. In this study, the index and compressibility parameters of a dredged soil were examined. The dredged soils were obtained from İzmir Bay. In the first part, Atterberg's limit test, sieve analysis, specific gravity, pH determination, scanning electron microscope analysis, Fourier transform infrared spectroscopy and consolidation test has been conducted for dredged samples which have various organic matter content (0, 4, 7 and 11%). In the next part, natural dredged soil samples were mixed with lime and silica fume in various proportions (5, 10, 15, and 20%), and compressibility performance was compared with the natural samples. It has been obtained that liquid and plastic limit, compression index, and void ratio change of natural dredged samples increased when organic matter content increased. While the silica fume has a negative effect on the compressibility behavior of dredged soil, the lime has a positive effect.