Three-Dimensional Finite Element Modeling of Pile and Pile Group System Response

Advancements in high-speed computing and developments in material modeling techniques are increasingly allowing for large-scale three-dimensional (3d) linear and nonlinear geotechnical finite-element (FE) simulations. The open-source computational platform OpenSees provides such 3d simulation capabilities for static/seismic ground-foundation analyses. With the aid of the graphical user interface OpenSeesPL (http://cyclic.ucsd.edu/openseespl), 3d computations for pile and pile group studies are greatly facilitated. Using this FE framework, an effort is made to capture key features associated with axial and lateral loading on piles and pile groups. For that purpose, the behavior of a laterally loaded 3×3 pile group at different pile-spacing scenarios is presented first and contrasted with that of the corresponding single pile scenario. Response under linear and nonlinear soil behavior representations is discussed. Lateral pile-group performance and efficiency considerations are investigated. Thereafter, the behavior of a large (8×4) pile group foundation supporting a high-clearance (for marine navigation) bridge deck is addressed. For seismic response evaluation, push-over combined axial/lateral loads along with a substantial moment are imposed. All studies are presented within a scope that highlights current modeling capabilities and directions for further research.