Inverse Method for Pile Dynamics Using a Polytope Method

Methods of utilizing data collected from pile top force-time and velocity-time records during impact hammer driving have been used to estimate the static capacity of piles for many years. These methods have been successful but still suffer from questions regarding uniqueness and soil characterization. The method proposed in this paper uses a two-dimension axisymmetric finite element model of the driven pile system coupled with a dimensionless soil model to reduce the number of parameters to be analyzed. These parameters are then applied to the soil in designated layers to determine the characteristics of a soil profile, using a polytope method for signal matching purposes. A static analysis is then performed on the system to estimate the static capacity by a designated method of static load test interpretation. An example from actual data is presented. The performance of the model shows reasonable correlation and opens up the possibility of further research.