The flow behaviour of deformed prefabricated vertical drains

Abstract There are various factors which affect the longitudinal permeability of a vertical drain and one of the most important is the soil deformation. As the surrounding soil settles during consolidation each vertical drain deforms since the drain is considerably less compressible than the surrounding soil. This paper describes an investigation on the combined effect of lateral pressure and the soil deformation on the longitudinal permeability of prefabricated vertical drains. A few common types of prefabricated drains were tested and variations in discharge capacities with soil settlement and lateral pressure were determined. The results show that soil settlement gives a significant effect on the discharge capacity.