Three dimensional modeling of laterally loaded pile groups resting in sand

Abstract

Many structures often carry lateral loads due to earth pressure, wind, earthquakes, wave action and ship impact. The accurate predictions of the load–displacement response of the pile group as well as the straining actions are needed for a safe and economic design. Most research focused on the behavior of laterally loaded single piles though piles are most frequently used in groups. Soil is modeled as an elastic-perfectly plastic model using the Mohr–Coulomb constitutive model. The three-dimensional Plaxis model is validated using load–displacement results from centrifuge tests of laterally loaded piles embedded in sand. This study utilizes three dimensional finite element modeling to better understand the main parameters that affect the response of laterally loaded pile groups (2×2 and 3×3 pile configurations) including sand relative density, pile spacing (s=2.5 D, 5 D and 8 D) and pile location within the group. The fixity of the pile head affects its load–displacement under lateral loading. Typically, the pile head may be unrestrained (free) head as the pile head is allowed to rotate, or restrained (fixed) head condition where no pile head rotation is permitted. The analyses were performed for both free and fixed head conditions.