STUDY ABOUT THE EFFECTS OF PILE SPACING ON THE PERFORMANCE OF PILE GROUP UNDER COMPOSITE LOADS, ADJACENT STRUCTURE LOADS, AND BENDING MOMENT IN SAND

Abstract

Pile group is a particular type of deep foundations which is designed and installed as the ultimate
solution to foundation construction, load transition to the resistant subsurface layers, providing lateral
resistance, and overcoming the poor performance of surface soils. Pile design should be done with
respect to structural consideration, the load-carrying capacity of the surface and surrounding soil,
settlement, and constructional, technical and environmental problems. Piles are mostly and widely
utilized in coastal and offshore structures, and sustain vertical and lateral loads. Considering the
imposed loads on structure, the effect of these loads on the pile behavior should be analyzed with an
appropriate method. In this study, a 4x4 pile group with piles of 100-cm diameter and center-to-center
spacing of 2, 3, 4 times the diameter is modeled using the Plaxis 3D foundation program, which uses
the finite element method, and the Mohr-Coulomb model, and the behavior of piles subjected to
loading, driven in sand, are investigated. Taking the achieved results, the mechanism of the pile group
behavior under composite loads, adjacent structure loads, and bending moment are calculated, and
displacement in the x-direction, y-direction and along the length, the bending moment and the axial
force for each pile within a distance of 2, 3, 4 times the diameter are attained.