Compressibility behaviour of natural and stabilized dredged soils in different organic matter contents

Dredged soils are re-usable, alternative, eco-friendly materials for various civil engineering applications. However, they exhibit high compressibility and low shear strength because of their high organic matter content. An accurate geotechnical characterization of dredged soils is fundamental before being used in engineering applications. The main objective of this study is to investigate the effects of organic matter content (OMC) on the geotechnical properties and compressibility behavior of dredged material in Izmir Bay. In order to improve the geotechnical properties and compressibility behaviour of dredged soil, samples were mixed with lime (L), thermal power plant fly ash (T) and volcanic slag (V). The structure and chemical compositions of dredged samples with different OMC (0%, 4%, 7%, and 11%) were investigated with SEM, XRD and FTIR analysis. Consolidation tests were conducted on specimens with various OMC and different percentages (5, 10, 15 and 20%) of three additives (L, T, and V). The results showed that as the OMC increased, the consistency limits increased and the specific gravity decreased. The compression indexes increase with the OMC increasing, are ranged between 0.32 and 0.10. While the L and T have positive effects on the compression index (C-c), the V addition acts adversely which increasedthe compressibility. (C) 2019 Elsevier Ltd. All rights reserved.