Relationship Between Various Consolidation Parameters of Compressible Soils

Consolidation of problematic soils such as soft or compressible soils with high clay content can be overcome by preloading along with Prefabricated Vertical Drains (PVDs) which is one of the most common techniques used over the past few years. Parameters that influence consolidation or rate of settlement at the site are coefficient of consolidation for horizontal/radial flow, smear effects such diameter of and permeability of remolded or disturbed soil in the smear zone. In this paper, degree of consolidation at the end of construction (Utc), final settlements, SfA, from Asaoka plots for degree of consolidation with time factor, under ramp loading with smear effects (s), the ratio of diameter of smear zone to that of drain, and kh/ks, the ratio of permeability on in situ soil to that of soil in the smear zone), have been developed for different unit cell diameter ratios, n, and time factors, Tc, corresponding to end of construction. A new method for the estimation of in situ parameters such as Cr, s and kh/ks of the smear zone from the in situ measured time-settlement plot, is proposed.