Behavior of vertical piles embedded in reinforced sand under pullout oblique loads

Abstract

The behavior of vertical single piles embedded in reinforced and non-reinforced cohesionless soil has been investigated with the help of small-scale model tests. These piles were installed in sand of different relative densities (<i>D_r</i> = 30 and 60%) and subjected to pullout loads of different inclinations. The model pile pullout tests were conducted using three reinforced concrete circular piles with different surface conditions (smooth, smooth with necking and bulging, and rough). The influence of sand reinforcement with geogrid on the uplift performance of the model piles was investigated. These investigations were carried out by varying the inclination of the pullout load, the embedded depth of reinforcement, the number of reinforcement layers, and the length of the reinforcement layer. The test results show that the pullout resistance increases with the concrete surface roughness, sand density and the inclusion of a reinforcing layer. It was also found that the effectiveness of the reinforced layer is dependent on the concrete surface roughness. This paper also discusses the effects of these parameters on the relative ground movement near the pile surface.