Field Estimation of Saturated Conductivity Using Borehole Test: Effect of Unsaturated Flow and Soil Anisotropy

Constant head borehole test is analyzed using a numerical model of the Richards equation. Steady state analysis is used to develop an efficient model scaled with respect to soil conductivity, thus allowing it to be used for the estimation of soil conductivities from field test results. Analytical formulae based on free-surface assumptions and those taking soil capillary effects into account are assessed by comparing with the numerical model results. The steady state analysis method is extended to the estimation of conductivities in uniform anisotropic soils. Field tests and results are discussed.