LAUSR

Raker piles are used more often in combination with vertical piles in a group where the lateral load per pile overshoots the value suitable for vertical piles. Under lateral loads, the behaviour of such group is generally different from that of a vertical pile group due to interaction of raker piles, resulting in the increase of the pile group capacity. A series of laboratory experiments have been carried out with Aluminium pipe pile of outer diameter 25.4 mm and thickness 1 mm in which the soil medium is of clean river sand. The lateral load tests were conducted in driven vertical and vertical–raker pile group configurations (two, three and four) in which raker piles were inclined at angle of 15º from vertical in different soil conditions namely loose sand (relative density, Dr = 30%), medium dense sand (Dr = 45%), dense sand (Dr = 70%). Based on these tests, the group efficiency for different soil conditions and the maximum bending moment were arrived. Based on the experimental results, a non-dimensional design chart has been developed for single pile, vertical and raker pile groups. This study establishes that the effectiveness of lateral load capacity of pile groups increases rapidly up to 50% of relative density of sand beyond which the increase was very minimal. The front raker pile group was efficient to carry lateral load because it resists more lateral load and bending moment than vertical and rear raker pile group configurations. The results demonstrate that the maximum bending moment occurs at a depth of 8D–10D (D—diameter of the pile) for all vertical pile group configurations and 10D–11D for raker pile group configurations.