Nonlinear Pile Foundation Analysis Using Florida-Pier

Florida-Pier is a nonlinear finite-element program designed for analyzing bridge pier structures composed of pier columns and cap supported on a pile cap and piles with nonlinear soil. The program was developed in conjunction with the Florida Department of Transportation (FDOT) structures division. In a recent addition, the piles were converted to include nonlinear behavior through the addition of a nonlinear discrete element. This element uses the true material stress-strain curves (steel and concrete) to develop its behavior and stiffness modeling. A description of the discrete-element model and a method to form its secant stiffness for any deformed position using material nonlinear stress-strain curves is presented. A summary of the modeling capabilities of the Florida-Pier program are also given. Two examples showing the newly added nonlinear pile element are given. The first example shows the response of a linear pile foundation as compared to a nonlinear pile foundation. The second example shows the capabilities of the program to model group pile behavior. The results for both examples are compared to COM624P (Wang and Reese 1993), the industry standard for pile analysis.