Kinking deformation of PVD under consolidation settlement of surrounding clay

ABSTRACT Kinking deformation by buckling of a PVD (Prefabricated Vertical Drain) due to consolidation settlement of the clay layer around it is discussed in this paper. A new testing device is manufactured for the purpose, and the deformation properties of two-kinds of PVD during consolidation of the surrounding clay are compared. It is concluded that a fibredrain made only of natural fibres can sustain the vertical permeability during a settlement strain up to 24%, while a PVD made of plastic loses its permeability before 19% strain. The field performance of both materials is also referred to.