On the Determination of Unsaturated Soil Property Functions

ABSTRACT: Unsaturated soil property functions can be estimated based on two relatively simple laboratory tests. These are: i.) the gravimetric water content versus soil suction test, and ii.) the shrinkage curve test. Data reduction and further calculations can be performed using a spreadsheet to compute unsaturated soil property functions, USPFs, such as permeability functions, water storage functions, and shear strength functions. Spreadsheets can also be used to expedite the calculation of other volume-mass versus soil suction relations. The calculations involve: i.) integration, ii.) differentiation and iii.) regression analyses to best-fit published equations for typical unsaturated soils behavior. The calculated USPFs can then be imported to numerical modeling software and used for numerical modeling.