EXPERIMENTAL AND NUMERICAL STUDY ON INFLUENCE OF OVERTURNING MOMENT ON LATERAL LOAD DISTRIBUTION WITHIN A PILE GROUP

A series of centrifuge shaking table tests with various pile group configurations, as well as a static pushover analysis using an average-stress-dependent nonlinear soil model, were performed to study influence of overturning moment on lateral load distribution within a pile group. The centrifuge shaking table tests show that, as ratio of overturning moment to total pile head shear load increases, lateral load carried by each trailing pile decreases with respect to that of leading pile. The numerical analysis suggests that the moment applied to foundation can produce shear forces at pile head that act oppositely outward with respect to the rotational center. This is probably the main reason why the lateral load carried by the trailing pile tends to decrease as the ratio of overturning moment to total pile head shear load increases.