Dynamically Loaded Pile in Overconsolidated Clay

A series of dynamic axial loading tests were conducted on a 273-mm-diameter steel pipe pile driven 13.4 m into a layered deposit of overconsolidated clay. A linear inertial mass vibrator was used to provide frequency sweep loadings from frequencies above to frequencies below the fundamental frequency of the pile-soil-cap system at three magnitudes of dynamic load. Superposition of a dynamic component of load of about 5% of the static capacity of the pile on a static biased compressive load resulted in slight nonlinear behavior and induced some residual increase in flexibility of the system. Two existing analytical models were studied in light of the measured performance of the pile and were found to yield appropriate solutions provided the soil parameters were selected properly.