Abstract: Based on the variational principle, the total potential energy of a general group of vertically loaded barrettes is established. By using the double Gauss numerical integration method, it is expanded to a simple equation of matrix form, in which a finite series is used to denote the vertical displacement of barrette shaft, Mindlin’s point-to-point displacement solution is applied to describe the force-displacement relationship of ground soils, and allowance is made for the non-uniform distributions of both the side shear stresses along the perimeter of the barrette shaft and the normal stresses at the barrette base. In light of the principle of minimum potential energy, an explicit solution is obtained for the load-settlement relationship of barrette groups. The proposed solution is verified from the comparisons of the calculated results made with an approximate three-dimensional method. Its merits in higher computational velocity and greatly reduced computer storage memory are also illustrated.

Key words: barrette, variational method, pile group, load-settlement relationship