Centrifuge investigation of the lateral response of pile groups in sand

Centrifuge model tests have been conducted on pile groups in loose sand to investigate their response to lateral loads . The behaviour of two different model pile groups and one single pile in loose sand were investigated in a series of centrifuge model tests. The model pile groups were installed and then horizontal load was applied using a horizontal actuator at 100g. Two of the piles in each of the p ile groups as well as the single pile were strain gauged to measure the b ending moment distribution. Initial investigation focussed on the lateral displacements and the rotations of the pile groups and the bendin g moment. These showed how the pile group shared the load between the front and back row. Manipulation of the bending moment data allowed p-y curves to be obtained for different depths for each of the pi les. These p-y curves are presented for the two pile group spacings and a re compared to the results from the single pile to deduce the group in teraction effects. The results show that although the group p-y curves wer e softer, the pile group response was stiffer than the single pile res ponse due to complex pile group interaction effects.