Collapse potential in unsaturated soil was first identified and quantified by researchers in South Africa. A landmark paper was published by Ken Schwartz in 1985 presenting the state of the art at that time. Since then, international researchers have expanded on the understanding of what collapsible soils might entail. These include saturated silts and sensitive
clays. This article highlights some of the new developments and presents a theoretical
yield model in an attempt to improve the understanding of the mechanism involved.