EFFECT OF INCLINED PILES ON THE DYNAMIC PERFORMANCES OF AN END-BEARING PILE GROUP

Inclined piles are prohibited by many codes in seismic area. Nevertheless the battered effect has not yet been clarified because very few data are available. In this paper, we focus on the influence of inclined piles on the inertial response of a group of two piles as an introduction to the more complex analysis of the performance of such groups under seismic loads. The present work is a comparison at reduced scale in the centrifuge of the response of two simplified end-bearing pile groups: a group composed of two vertical piles and group composed of a vertical pile and a pile inclined at 25° to the vertical. Each pair of piles is linked by a massive pile cap rigidly fixed on the piles. Repeated horizontal impacts were applied on the pile cap. The effect of the pile inclination on the response has been evaluated in terms of frequency analysis, cap acceleration, bending moment profiles and axial load at each pile. Results highlight that the inclined pile increases the pile group stiffness, decreases the maximum bending moment below the soil surface and increase axial load in each pile of the group.