Optimum Design of Three-Dimensional Pile Groups in Nonlinear Soil

Analytical solutions have recently been developed for analyzing the behavior of piles in a group subjected to loading in three-dimensional space. The piles may be installed vertically or on a batter and their heads may be fixed, pinned, or elastically restrained by a rigid pile cap. The several components of the analytical method have been coded and iteration is used to accommodate the nonlinear response of the soil around each pile in a group. With availability of a rational and convenient tool, the engineer may consider several alternatives in a design, including pile spacing, batter angle, and type of pile. This paper presents an example of use of the analytical tool to optimize a design. The example is site-specific, but the demonstrated procedures are fully general.