Centrifuge model tests of deformation and failure of nailing-reinforced slope under vertical surface loading conditions

A series of centrifuge model tests was conducted on a nail-reinforced slope under vertical surface loading conditions considering different slope gradients and nail lengths. The ultimate load of the slope decreased significantly with the increasing gradient of the slope or the decreasing nail length. The slope exhibited significant progressive failure that was captured by a displacement-based analysis. At first, the vertical load caused local slippage near the slope toe and the inner edge of the loading plate. Then, it extended to the interior of the slope and eventually to an entire slip surface. The H-surface was obtained according to the measured displacement to distinguish the zone where the surface load influenced the horizontal displacement of the slope. The H-surface and the position where the peak vertical displacement occurred in a horizontal line moved from the internal slope to the slope surface from the slope top to the slope bottom. This demonstrates the dispersion of the surface load application within the slope. The deflections of nails can be obtained from the corresponding soil deformation. The deflection of nails increased with the increasing load pressure, and exhibited diverse features in its distribution in the upper and the lower parts of the slope.