Numerical evaluation of prefabricated vertical drain enhanced soil vapour extraction system

The aim of this study is to investigate numerically the performance of a prefabricated vertical drain (PVD) as a soil vapour extraction well, and the pattern of the induced air flow. A validated numerical model for a single PVD extraction well is developed based on the result of a well-designed laboratory air-pumping test. The results of the validated numerical model are used to evaluate the flow efficiency of a PVD extraction well. The validity of the simple analytical approach to determine air permeability based on the results of air-pumping tests is also discussed. The output of this study highlights the influence of PVD well resistance on the overall performance of soil vapour extraction systems, and the effect of the PVD's oblong cross-section on the air flow characteristics.