GEOLOGICAL AND ENGINEERING STUDIES ON THE LIME-TREATED SOFT CLAY SOILS IN NORTH DELTA AREA, EGYPT

Abstract

The geological distribution of soft clay soils in the northern Nile Delta region as well as the various aspects of soil improvement by lime-mixing technique, have been studied throughout an experimental programs. In order to accomplish this, a total of 822 soil profiles were collected from 411 places in the northern Nile Delta region, from Tanta City in the center to the Mediterranean Sea in the North and from El-Manzala City in the east.to Idku City in the west. The soil profiles represent the upper 20m of the Holocene Bilqas Formation.

To evaluate the effect of lime on soft clays, the natural soil samples were collected from five places (Idku, AI-Burullus, Fuwa, El-Manzala and Tanta Cities) cover nearly all types of soft clay soils. The lime was added to each soil in room temperature in the amount of I, 3, 5 and 7% by weight of natural sample and thoroughly mixed by hand until homogeneity is nearly reached. The study includes geological (grain size analysis, mineralogical composition, microstructure . observations) and engineering studies (index properties, soil strength and compressibility behaviors).

Soft clays are normally soft in consistency due to their higher moisture content and thus they cause many settlement problems and extensive damages of buildings. In views of this, their aerial distribution is of almost importance for engineering purposes.