Revisiting Hvorslev's intake factors using the finite element method

Intake or shape factors are geometric constants used in the interpretation of in-situ permeability tests. These constants are specific to a particular instrument or, more precisely, the test cavity geometry. There are many methods available for field permeability measurement. These include tests in boreholes and in driven piezometers, and also purpose-built permeameters. Typically, a constant head or constant flow test is carried out and interpreted from Darcy's flow rule in the form of Hvorslev's general equation (Hvorslev, 1951):

where k is the coefficient of permeability (m/s), Q∞ is the flow...