Effect of the overconsolidation on the consolidation of clays

Usually the consolidation of clayey soil theories take into consideration the fact that this phenomenon takes place only along the virgin line. Most frequently, however, natural soils behave as overconsolidated, if not by a previous loading, by the effect of aging. Several theoretical models were proposed, considering the consolidation taking place in recompression-compression lines; such models, however, deal with thin layers, which means that the initial void ratio does not change throughout the depth. A theoretical model for overconsolidated thick layers was developed. The model considers the large strains, the selfweight of the layer, the non-constant consolidation parameters and the stress-strain non-linearity. The application of the proposed model to a typical sedimentary soil shows results very distinct from those found through the Terzaghi's and Mikasa's theories for normally consolidated clays: the progress of consolidation is faster and the rate of strain is slower than the rate of pore pressure dissipation.