  The batch settling test is widely used to estimate the compressive rheology
of strongly flocculated colloidal suspensions, in particular the compressive
yield strength and hydraulic permeability. Recently it has been discovered that
wall adhesion effects in these tests may be significantly greater than
previously appreciated, which can introduce unbounded errors in the estimation
of these rheological functions. Whilst a methodology to solve the underlying
static problem and correct for wall adhesion effects has been developed, this
method is quite complex and unwieldy, involving solution of a 2D hyper-elastic
constitutive model for strong colloidal gels. In this paper we develop a highly
simplified 1D visco-plastic approximation to the hyper-elastic model which
admits analytic expressions for the equilibrium solids concentration profile
and bed height. These expressions facilitate robust estimation of the
compressive yield and wall adhesion strength via nonlinear regression of
experimental data in the presence of small measurement errors.
