Parametric study to evaluate the performance of horizontal drains as mitigation technique against soil liquefaction

In the framework of the LIQUEFACT project a series of centrifuge tests were conducted at ISMGEO (Italy) to verify the effectiveness of three mitigation techniques against soil liquefaction. This paper is focused on the study of horizontal drains as mitigation measure against liquefaction. The centrifuge layout with horizontal drains was numerically modelled and the change of boundary conditions reproduced by the FE code Plaxis 2D. Additionally, slightly different layouts from those tested in the centrifuge were also modelled to expand the scope of the experimental work. Horizontal drains were installed in the model, to analyse their effectiveness in reducing the pore pressure build up as a function of their spacing. The soil was characterized by an advanced coupled soils constitutive model implemented in the Plaxis code: PM4sand. The input parameters for the model are evaluated on the basis of both laboratory element tests and centrifuge tests.