ASSESSMENT OF FACTORS AFFECTING COLLAPSIBILITY OF UNSATURATED SANDY SOIL

Abstract

In this thesis, an experimental program is performed to illustrate the influence of different parameters on the collapsibility of ten sandy soils. Moreover, the collapse potential (CP) of these samples is determined using the single Oedometer Test. Then, the effect of related parameters including fine content, type of fines (silt/clay), initial water content, pre-wetting pressure, and wetting/drying process have been investigated. Also, the initial and pre-wetting matric suction values are measured using the filter paper method (ASTM D5298) to investigate its role on collapsibility. The soil water characteristic curves (SWCCs) could be generated, which can be used in numerical modeling of these types of soils. Scanning Electron Microscope (SEM) is conducted to illustrate the role of fine type in the collapsibility mechanism. Finally, different correlations suggested by literature and the Egyptian Code to determine the susceptibility of soil to collapse are studied.