Simple plane strain modeling of prefabricated vertical drains improved soft deposit

A novel and straightforward plane strain method has been developed for modeling PVD-improved soft deposits. The core of the method is a new derived formula for the equivalent horizontal hydraulic conductivity ( k hp ), which incorporates the physically realistic time-dependent hydraulic gradient and rigorously maintains consistency in both the improvement volume and total discharge between the plane strain model and its benchmark axisymmetric counterpart. The formula also comprehensively accounts for smear effects and well resistance to enhance the realism and applicability of the proposed method. Validation against two field case histories demonstrated that the proposed method satisfactorily simulates both settlement and excess pore water pressure. Crucially, the predictions were consistently superior to those of existing methods, highlighting the practical advantages of the new k hp formulation. Furthermore, this study investigated the comparative performance of simulating PVDs with solid versus drain-line elements. The analysis revealed that the selection of element type is governed by the significance of well resistance. While both methods are effective when well resistance is negligible, the solid element approach is necessary for accurate predictions in cases where the PVD’s finite discharge capacity limits the overall consolidation rate. This finding provides valuable practical guidance for selecting the appropriate modeling technique.