Towards the application of unsaturated soil mechanics in practice

Abstract

It has long been recognised that the principles of conventional saturated soil mechanics can be an oversimplification of soil behaviour, particularly in the arid climate of southern Africa. This knowledge has led developers of certain commercial software packages to incorporate some unsaturated functionality, particularly for flow and stability analyses. Despite its importance, implementation of unsaturated soil mechanics in geotechnical engineering has yet to become a part of standard practice. While the input requirements for such analyses require, at the very least, the relationship between water content and matric suction, these relationships often tend to be assumed by engineers, due to the lack of local test facilities capable of determining these parameters. Further factors hampering the application of unsaturated soil mechanics in practice are the complexity and time required for unsaturated soil testing, as well as the difficulty in measuring high soil suctions within a reasonable time frame. Recent advances in suction measurement have gone some way towards addressing some of these shortcomings.