TIME-DEPENDENT DEVELOPMENT OF STRENGTH IN DREDGINGS

Environmental or economic considerations or both, often dictate that maintenance dredgings be placed within diked containment areas to form landfills of limited quality. Documented in this investigation is a 4-yr history of the development of shear strength with time at four typical landfill disposal sites near Toledo, Ohio. When synthesized in accordance with the different deposition histories of the sites and the basic assumption that the materials in each of the four sites are essentially similar, a reasonably meaningful history of shear strength development at a hypothetical dredging disposal site over a period of about a decade can be deduced. Methods of shear strength determination include field vane, laboratory vane, fall cone, and unconfined compression tests; the laboratory tests were conducted on continuous samples obtained by means of a specially developed manually operated piston sampler, and comparisons are made with the results of the field tests.