Beneficial use of Savannah River dredged material in large-scale geotechnical applications

Abstract

The Port of Savannah is located 18 miles inland from the Atlantic Ocean in the southeastern United States. Historically, 6 million cubic meters of river sediment is dredged from the Savannah River each year; however, the Savannah Harbor Expansion Project (SHEP) (Georgia, USA), which is proposed to accommodate post Panamax ships in the channel, will result in further increased dredge volume for disposal. Because dredge materials are currently disposed on land, this study was focused on identifying possible beneficial uses of dredge material in order to reduce the requirements for land disposal. A laboratory-based study was performed to assess the feasibility of large volume geotechnical use options for dredged sediments. Four samples were collected from the disposal facilities and characterized using physical, chemical and morphological analysis techniques, including grain size distribution, Atterberg limits test, specific gravity, scanning electron microscopy (SEM), laser diffraction particle size analysis (PSA), total organic carbon content (TOC), loss on ignition (LOI), and thermogravimetric analysis (TGA) analysis. The compactibility of the dredge was quantified using the standard Proctor test. Overall, characterization and compaction results demonstrated that the dredge material is viable for use as a nonstructural fill material, indicating that additional research and feasibility studies focused on specific beneficial use options is warranted. These results have important implications on the potential for beneficial use of the dredged sediment.