Characteristic of Unsaturated Residual Soil: Field, Laboratory and Computer Model Analysis on the Behavior of Unsaturated Residual Soil, Influencing the Slope Factor of Safety with Rainfall

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 and soil moisture characterizes. The basics of this study is to perform full scale research on every aspect of unsaturated soil theory by performing site investigation, laboratory testing, field instrumentation, field rainfall simulation experiment and computer analysis. All the data are compiled to conclude the influence of rainfall infiltration on insitu soil shear strength, drop in matric suction with time and the effect on slope factor of safety during rainfall.