Numerical Investigation of Consolidation Induced by Prefabricated Horizontal Drains (PHD) in Clayey Deposits

In this work, the process of prefabricated horizontal drains (PHD) induced consolidation in clayey embankment fills is investigated by a numerical approach. Based on spacing parameters, the suitability of axisymmetric and plane strain conditions for modeling the drain has been studied, and the suitability zones and matching functions have been proposed. The implications of the use of elastoplastic models to simulate the behavior of in situ soil on the suitability zones and matching functions have also been studied. The numerical results were compared with the analytical unit cell solutions for axisymmetric and plane strain conditions. Further, the effect of PHD in improving the consolidation behavior of various soil types has been analyzed in terms of pore pressure dissipation and settlement. The studies showed that the drain improved ground is best modeled under axisymmetric conditions at lower spacing ratios, and plane strain conditions simulate the more distantly spaced cases. PHD was found to accelerate the consolidation process in soft soils significantly, and the effect was found to be most prominent in highly plastic soils.