Incorporating a flow pump into a conventional triaxial laboratory system allows fluid to be supplied to or withdrawn from the base of a sediment sample at small and constant rates. An initial transient record of hydraulic head versus time is observed which eventually stabilizes to a constant steady state gradient across the sample; values of hydraulic conductivity can subsequently be determined from Darcy's law. In this paper, analytical methods are presented for determining values of specific storage and hydraulic conductivity from the initial transient phase of such a constant flow rate test. These methods are based on a diffusion equation involving pore pressure and are analogous to those used to describe the soil consolidation process and also to interpret aquifer properties from pumping tests.
Additional publication details
THEORETICAL ANALYSIS OF THE TRANSIENT PRESSURE RESPONSE FROM A CONSTANT FLOW RATE HYDRAULIC CONDUCTIVITY TEST.