PVD-assisted consolidation of dredged sediments in a CDF: design of the test field

A confined disposal facility (CDF) was built at the Ancona Harbour (Italy) to host contaminated dredged sediments. The Port Authority intended to get the chance to use the reclaimed land as a storage area. Since dredged sediments typically have very high void ratios when disposed in a CDF, their consolidation is essential to achieve proper mechanical characteristics. Consolidation of sediments by prefabricated vertical drains (PVDs) and embankment preloading is being planned. Since large strains are expected, nonlinear constitutive relations for compressibility and hydraulic conductivity are required to model consolidation processes. For this purpose, sediments were characterised by laboratory tests to determine compressibility and permeability laws, followed by field investigations (CPTUs and dissipation tests). A full scale test field has been designed to calibrate modelling and set up the operating procedures. The paper illustrates and discusses the design criteria of the test field.