An Analysis of Use of Guelph Permeameter in Estimating Saturated Hydraulic Conductivity

Abstract

The use of the method of the Guelph permeameter has, in many situations, shown to provide unrealistic results such as negative values of the hydraulic conductivity. Although this is attributed essentially to soil heterogeneity, other factors inherent to the test method itself can also interfere with the results. The primary objective of the present work is to analyze the performance and the variability of the Guelph permeameter in determining the hydraulic conductivity of sandy soils and other loamy soils when the one-stage or two-stage load method is employed. Inherent difficulties in meeting with the K_fs condition of isotropy in the two-stage load method are evidenced. Notwithstanding, the use of the two-stage load method is still possible when operational errors are minimized. In compensation, the one-stage method is employed in determining only the saturated hydraulic conductivity (K_fs) and only a reduced number of tests is needed. However, the appropriate choice of the parameter a and the height (H) can minimize the erros associated to estimating K_fs.