Dr. Mann’s assertion that experimentally-based results trump those of theory is only as convincing as the validity of the results. As Dr. Mann himself acknowledges in his comment, the analysis of the fluid flow in his study was based on a finite element model, not on direct experimental measurements 1. Only the boundary conditions used for the finite element analysis were based on experimental data. Therefore, their conclusion supporting the weeping mechanism is only as good as their finite element modeling assumptions, which have a major limitation.

The limitation of their study is that “Strains in the porous layer are assumed uniaxial, i.e., displacements of the matrix are constrained to the vertical (radial) direction…” 1. It can be shown from the basic law of conservation of momentum that under the assumption of uniaxial displacement along the vertical direction, the gradient in fluid pressure can only vary along that...

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