Large displacement numerical study of 3D plate anchors

This paper discusses a numerical study carried out in the frame of the development of a new application of plate anchors for landslide stabilization. The plates are positioned on ground surface of the slope and linked to a deeper stable layer with a steel grouted bar, thus acting as discontinuous elements that contrast the slope movement. This technique is less expensive compared to standard retaining structures, especially in medium and deep landslides. Moreover, plate anchors can bear large displacements of the unstable moving mass without losing efficiency. Evaluating the stabilizing force and its optimization in relation to the plate shape and interspace are of great interest. Numerous studies have investigated the bearing capacity of rectangular and circular thin plates at small strains, but the performance of alternative shapes, such as cones or truncated cones, has never been considered. The numerical study here presented applies the Material Point Method to investigate the behaviour of plate anchors with different 3D shapes at large displacements. The numerical model is validated with the results of some small-scale laboratory tests. The pull-out resistance, the soil stress and displacement fields around the plate, as well as the group effect have been investigated, thus obtaining preliminary indications for the design of these elements.