To clarify some of the inconsistencies in the research of equivalent diameter of PVDs, we constructed 3-D consolidation models of PVDs and sand drains using ABAQUS and compared models with and without sand drain resistance. When the sand drain resistance was included in the model, the equivalent diameters of the sand drains were 30, 65, 78, and 100 mm (for a 100-mm-wide, 4-mm-thick PVD) corresponding to PVD drainage depths (or soft soil layer thickness) of 2, 5, 8, and 10 m. Except for the depth of 2 m, the other results were higher than the values found in previous studies. The equivalent dia...