Unsaturated soil mechanics has undergone tremendous amount of research both in field and laboratory creating new concepts and theories for practicing engineers. The behavior of unsaturated soil in the field is very sensitive to the flex changes of ground water table and rainfall infiltration. This research covers in depth the study of unsaturated residual soil behavior in both laboratory and field. Various research tools were used to measure important data such as matrix suction, rainfall records, infiltration rate, surface runoff, unsaturated and saturated soil shear strength...