Structural pounding occurs frequently during strong earthquakes
between two buildings or different parts of the same building. Structural pounding can also occur in bridges in the longitudinal direction at the abutments or at expansion hinges, and laterally between narrowly separated superstructures. The dynamic behavior of a damped single-degree-of-freedom (SDF) structural system with onesided pounding during an earthquake is examined. The structural response of the SDF structure with either elastic or inelastic structural behavior is analyzed. The pounding phenomenon is modeled as a Hertz impact force, which represents the behavior of two colliding bodies during a completely elastic impact. Artificial, as well as actual earthquake excitations, and realistic parameters for the pounding model are used in numerical evaluations of the seismic response. The effects of separation distance and inelastic structural behavior on the magnitude of the pounding force are examined. An increase in the damping energy absorption capacity of the pounding structure results in the reduction of the pounding forces. The present model and method of analysis can be used in investigations of pounding between buildings or pounding which occurs in bridges during strong earthquakes.