Pile Group Response to Static Lateral Load in Cohesionless Slope Crest for Varying Eccentricity: A 1-g Laboratory Study

The geometry of the ground plays a vital role in the lateral capacity of the pile foundation. This paper presents the effect of slope and eccentricity in a pile group while applying the load laterally. A series of experiments were conducted in the laboratory in a scaled down set for a slope of 1V:2H at a relative density of 70%. The load is applied as a frictionless load, in the form of dead weights, eccentrically at different free heights from the slope crest with respect to the stiffness factor (T) in cohesionless soil. The parameters varied are the pile group (1 × 2 and 2 × 2), spacing (2.5, 3 and 4 times pile diameter) and the eccentricity (0, 0.5 and 1 T). From the test results, it is observed that with an increase in the number of piles, the lateral capacity of the pile increases linearly. From the bending moment curves, p–y curves are plotted for the pile group placed at the crest. With varying eccentricity or free length in loading, the lateral capacity decreases due to the initial stiffness developed. As the eccentricity of the pile group increases from 0 T to 0.5 and 1 T, the initial stiffness reduces by 34% and 50%, respectively, for 1 × 2 pile group and 26.7% and 66.67%, respectively, for 2 × 2 group. A new non-dimensional chart is developed to understand lateral load behaviour of pile group.