Performance of laterally loaded pile group in clay

A series of centrifuge model tests was conducted to examine the behaviour of laterally loaded pile group in normally consolidated kaolin clay. The pile groups have a symmetrical plan layout consisting of 2, 2x2, 3x3 and 4x4 square piles with a center-to-center spacing of three or five pile widths. The piles in a group are connected by a solid aluminum pile cap placed just above the ground level. The test results expressed in terms of bending moment, soil reaction and lateral deflection profiles are presented in this paper. The findings reveal the shadowing effect phenomenon in which the front piles experience larger bending moment than the rear piles under the same applied load. It is also established that the pile group efficiency reduces significantly with increasing number of piles in a group.