Discussion on "Theoretical Evaluation of the Transient Response of Constant Head and Constant Flow-Rate Permeability Tests" by M. Zhang, M. Takahashi, R. H. Morin, and T. Esaki

In this paper, an a posteriori error estimator suitable for use in geotechnical engineering has been developed. This error criterion is based on the superconvergent patch recovery method with equilibrium and boundary conditions method, taking into account Biotʹs coupled consolidation theory. After testing on several problems, the introduction of pore pressures and other parameters into the error estimator was found to improve results significantly, providing a convergence rate of approximately two orders higher than the global rate. © 1999 Elsevier Science B.V. All rights reserved.