The shallow Soft Clayey deposit is common in Alexandria-Egypt. Many soft clays in its natural state
unsuitable for support any structure. Thus, improvement treatments exist to strengthen these soils so that they can have adequately bearing capacity without undergoing failure or producing substantial excessive
settlement post construction and applied loads to them. This paper presents case study of improved site of city center which reclaimed Maryout Lake, where the highly compressible clay with water content varies
from 250% near the surface to 90% at the base of the shallow clay deposit. A prefabricated vertical drain
with preloading has been used in improved this soil. Values of shear parameters and consolidation
coefficient back calculated from field measurements, and have been compared with the values from lab and in situ tests. The study provides different relationship from comparisons of prediction and estimation
compressibility and consolidation settlement from laboratory studies and particularly field case study.
Also, some correlation related the compressibility with index properties of soft clay is presented.