Centrifugal model tests on batter pile groups under eccentric lateral loads

A series of centrifugal model tests are conducted to investigate the behavior of pile groups in sand subjected to eccentric lateral loads, especially the role of batter pile groups in resisting lateral or eccentric loads. The preparation and the procedure of the tests are described. The test results reveal that the eccentric distance of the lateral loads will affect the lateral response of the pile groups to some extent within the experimental range, but have little effect on the torsional behavior of the pile groups. The bearing capacity of the plumb pile group under lateral loads with eccentric distance of 4.3D is higher than that of zero and 7.1D. The capacity of the batter pile groups subjected to lateral, eccentric or torsional loads is much higher than that of the plumb pile groups. Under the eccentric loads, the differences between the lateral displacements of individual piles within the batter pile groups are larger than those in the plumb pile groups, and they also increase with the eccentric distance of the lateral loads. The shear forces and lateral displacements at head of individual piles are different in direction. The axial forces of individual piles within the batter pile groups are dramatically larger than those in the plumb pile groups under the same load condition, which illustrates that batter pile groups can more effectively resist the lateral loads than the plumb pile groups by taking full advantages of the axial capacity of individual piles.