Abstract: Preloading with vertical drains is an effective treatment method for a soft clay foundation. Existing analytical solutions and numerical simulation based on Terzaghi and Biot,s theories are complicated for settlement assessment. This paper presents a simplified method for settlement assessment by adjusting permeability coefficient based on equivalence of consolidation degree, and then treating the soft clay foundation with vertical drains as a homogeneous stratified foundation. A case study was used to exam applicability of the method. The comparison between the simulated results with FEM and observed deformation shows a good matching. The presented method can provide a simple and practical assessment of settlement for a soft clay foundation treatment with vertical drains.