Book Description

This research program was initiated with the overall objective of evaluating the usefulness of dredged sediments as landfill material. The study is limited to the deposition of polluted fresh water dredgings from the Great Lakes area, and the major effort was centered around four disposal sites in the harbor serving Toledo, Ohio. A comprehensive sampling and testing program was undertaken in the field and in the laboratory to determine the engineering characteristics of hydraulically placed maintenance dredgings and the water quality effects associated with a typical dredging and disposal operation. Several thousand chemical analyses were conducted to assess the pollution potential of dredged materials under chemically treated and nontreated conditions. Several series of flocculation-sedimentation, sedimentation-leaching, repeated leaching, and evaporation tests were conducted to study the possibility of stabilizing these materials with chemical additives and to evaluate the effects, if any, of such chemicals on the leachates. Numerous index property tests were performed for classificatory purposees, and several correlations among different properties and the results of the index tests were established. An extensive field monitoring program was undertaken to evaluate the effects of a typical dredging and disposal operation on the water quality parameters of the environs. Periodic vane shear tests were conducted in two of the areas, and settlement plates were installed at one site to determine the time-dependent variations in the strength and settlement, respectively. Several in situ permeability tests were conducted on the foundation soils and the dredged materials to evaluate drainage conditions. Finally, a one-dimensional mathemathical model was developed to assess the relative importance of gravity drainage and evapotransporation on the desiccation and consolidation of a landfill composed of maintenance dredgings.