Porosity estimation of unsaturated soil using Brutsaert equation

Abstract

Although the porosity is a crucial parameter for understanding the soil behavior under static and dynamic loading, estimating the porosity of unsaturated soil is difficult owing to the various input parameters required. The objective of this study is to suggest a technical method to obtain the level of porosity based on the elastic wave velocity in unsaturated soil. The Brutsaert model, which utilizes the theory of wave propagation, is applied to modify the proposed method in terms of the porosity of unsaturated soil. The soil compressional wave velocity is gathered through a seismic refraction survey, and the porosity distribution at different depths is estimated. A dynamic cone penetration test is applied to verify the converted porosity based on the compressional wave. The two porosities estimated through the wave propagation and penetration show similar trends. Furthermore, a special validation is performed to determine whether the energy dissipation can be ignored in the compressional wave propagations under this experiment condition. The results of this study indicate that the suggested technique is useful for obtaining the porosity in unsaturated soil.