الفهرس 
LITERATURE REVIEWOnly 14 pages are availabe for public view
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Abstract
Swelling behavior of shallow foundations resting on treated expansive soil is generally affected by
different factors. Some of these factors are related to the boundary conditions controlling the site
deposition and the mode of water migration. while the others are related to the employed treatment
technique for damping the heave potential of the expansive soil. Although the utilization of some
treatment techniques were considered as an adequate techniques for reducing both swelling and
swelling pressure of expansive soils, during the last decades, many problems occurred for shallow
foundation buildings constructed on treated expansive soil.
The main objective of the present thesis is to study the effectiveness of some widely used treatment
techniques to eliminate or damp the swelling behavior of expansive soil and also to study the factors
that causes differential movement between footings. A case study of an inclined super structure at the
middle Mokattam plateau was studied. Although the expansive soil layer were treated with sand
replacement but it failed in preventing the harmful effects due to the differential heaving of soil, and
this can be attributed to the presence of water seeping from a nearby drainage utility below the
replacement layer. The stratigraphy of the middle Mokattam plateau was presented and the
geotechnical properties of the soil at the site area were investigated. The movement of the building
was simulated depending on six survey readings during a time period reaches about four years nearly
after the building inclination. Also the horizontal displacement components for the building were
obtaind (using two semi empirical methods) and compared with the measured values to decide the
best and more suitable method which can be used in predicting heave of footings. A laboratory testing program was designed to determine the swelling behavior and differential heave
effect on shallow footings resting on treated expansive soil employing different treatment techniques
using a large laboratory model. The geotechnical properties were investigated and classified using
.
direct and indirect methods. The expansive soil was treated using sand replacement, sand
replacement with 5% lime, expansive soil with 5% lime stabilization and sand replacement with
horizontal plastic barriers. Footings heave, moisture distribution, and differential heave between
footings were measured and predicted using empirical and semi empirical equations. Loading
conditions, level of horizontal barrier and water leakage spacing from footings were taken in
consideration.
All the used treatment techniques succeeded in decreasing the final heave with nearly the same
value. The use of plastic horizontal barrier at the top of replacement layer succeeded in distributing
the moisture uniformly over the expansive soil layer in case of water seeping from the sheet, and this
result in uniform heave of footings with time. While in case of water seeping from the plastic sheet
used at bottom of sand cushion, this concentrated the leakage at definite point which results in high
differential movement between footings. This research project has helped to identify the expansive
soils in this area and some of its associated problems and to increase the effectiveness of the
proposed treatment techniques, which can help in mitigating the structural damages originating from
the behavior of expansive soils.