الفهرس 
Chapter ( 1 ) : IntroductionOnly 14 pages are availabe for public view
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Abstract
Expansive soils show high volumetric changes with changes in water content. When they imbibe water during wet season, they expand and upon evaporation thereof through dry season, they shrink. Because of this alternate swelling and shrinkage, structures founded on them are severally damaged. Potentially problematic shrink-swell soils can be found almost anywhere in the world especially in arid and semi-arid regions of the tropical and temperate climate. In Egypt, expansive soils present in many areas such as Aswan, Kom Ombo, Esna, Assuit, Minya, Beni Suef, Fayoum, El-Wadi El-Gedid, EL- Mokatam, 6 - October, Zahra EL-Maady ...etc. Due to the lack of experience pertinent to characterization and dealing with problematic shrink-swell soils in Egypt, many defects appear in some structures established in development projects. Density and severity of problems associated with the presence of shrink-swell soils differ from region to another. Many factors contribute to the problem such as: soil type, soil properties, foundation type, nature of project, and the extension of development zone...etc.
In this research, extensive experimental work has been performed on sixty two (62) soil samples obtained from various sites all over Egypt. The investigation targeted to assess volumetric change and moisture diffusion characteristics as well as index properties of unsaturated clayey soils. Test results confirm that volumetric change and moisture diffusion characteristics for unsaturated soils can be reasonably related to conventional soil index properties. Based on the obtained comprehensive database of results, ten (10) equations expressing relationships among different engineering properties of unsaturated shrink-swell soils in Egypt are proposed and discussed.
In addition, a laboratory model was constructed ( Seven Models ) with changing replacement soil type used. Then verification was carried out for these cases using GeoStudio 2007 finite element 2D program. The results showed that the numerical models give satisfactory values to the laboratory models as discussed in this thesis.
Also, extensive numerical study ( 57 Cases ) was carried out to simulate the shallow foundations on unsaturated shrink-swell soils using different types of foundation soils, replacement soils, depth of replacement soils, width of footing, and loads which effect on the footings. The parametric study outcomes are then presented in the curves. The parametric study focuses on studying the efficacy and ability of the soil replacement in minimizing heave of foundations laid on expansive clay. The results proved the efficiency of replacement soils in reducing the heave of expansive soil and showed that the heave can be reduced with increasing both footing width and depth of replacement soils, and increasing the applied pressure on footing rested on very high and medium potential expansiveness foundation soils.