Abstract:
Steel foundations are an alternative to concrete foundations and can be designed to cross-sectional configurations ranging from triangular and square to other multi-side shapes to accommodate various loading and performance criteria. Adding lateral extensions (hereby called wings) along the length of the foundation can increase the foundation’s uplift, torsional and lateral load capacities. DiGioia Gray staff developed a methodology to establish the optimal design for multi-facetted, winged deep steel foundations. A finite element model is used to represent the steel components and the nonlinear subsurface behavior of the foundation system. Since the geometry of the pile can be complex, an optimal design needs to be fine-tuned to the specific site conditions. Thus, we created a pre-processor tool to generate the finite element model for various foundation configurations, including varying values for the number and size of wings, depths of embedment, reveal/stickup heights, top plate geometries, and subsurface profiles. The analytical model has been partially validated through full-scale testing and the methodology has been applied to two installed projects to date.