Role of unsaturated permeability function in seepage analyses

Abstract

Unsaturated permeability function is the key parameter in seepage analyses. The unsaturated permeability function is often estimated from soil-water characteristic curve (SWCC) by means of estimation models. However, different estimation models result in different unsaturated permeability functions. In this paper, the effect of using different unsaturated permeability functions, as estimated by the different models, on seepage analyses is presented. The different unsaturated permeability functions can affect the results of seepage analyses which in turn may affect the design of earth structures. In this study, a column of residual soil was subjected to typical rainfall conditions in Singapore through numerical modelling. The results of the analyses show that infiltration characteristics of the residual soil column were noticeably affected when different unsaturated permeability functions were used for the same soil.