Two square and embedded shallow foundations have been dynamically loaded at the National Geotechnical Experiment Site (NGES) on the campus of Texas A&M University (TAMU) via four dynamic loading devices implemented in several configurations. The dynamic load and vibration responses of the foundations were measured via appropriate electronic instrumentation. Utilizing appropriate equations of motion and system parameters, and the measured load and vibration responses, dynamic impedance functions were backcalculated for the vertical, horizontal sliding, and rocking modes of vibration.