VERIFICATION OF AN EQUIVALENT SIMULATION METHOD FOR A CLAY-SAND-CLAY SUBSOIL PRECONSOLIDATED BY VACUUM-SURCHARGE

To carry out a 2D simulation of soft ground improved by vertical drains under embankment combined with vacuum preloading, a method to convert the axisymmetric consolidation of the drain to plane-strain consolidation is needed. The paper presents and verifies a proposed conversion method for a sandwich subsoil, where a sand layer is sandwiched between two clay layers, which is often found in many areas in Japan. The analyzed results showed that the proposed method produced very good matching results, not only for the drain having no-well resistance, but also for the drain having high well resistance in the subsoil.