NUMERICAL-ANALYSIS OF SEDIMENTATION AND CONSOLIDATION BY THE MOVING FINITE-ELEMENT METHOD

Traditionally, sedimentation and self-weight consolidation have been v iewed as physically distinct processes requiring separate treatment. R elatively recently, Pane and Schiffman(1) and also Philip and Smiles(2 ) have suggested that the two processes may be described by a single p artial differential equation, essentially that of Gibson et al.(3) The former suggests a modification of Terzaghi's effective stress princip le while the paper by Philip and Smiles suggests that a suitable model ling of material properties is sufficient. We have adopted the latter approach by allowing for the compressibility of the material in questi on to change abruptly from finite values to infinity in the so-called transition region which delineates that portion of space where effecti ve stress is zero from that where effective stress in non-zero. This p rocedure gives rise to serious difficulties when trying to solve the g overning partial differential equation numerically. These difficulties are circumvented by using a relatively new numerical technique known as the Moving Finite Element (MFE) method. The MFE method is especiall y effective in solving problems having solutions that characteristical ly exhibit shock-like structure. The modelling of sedimentation and se lf-weight consolidation from a single governing model is an ideal cand idate for MFE due to the abrupt, almost discontinuous change in void r atio displayed in the transition region.