During earthquakes, adjacent buildings with insufficient separationdistance often collide with each other. This collision called seismicpounding and each time it occurs, buildings are subjected to short lateralimpact force in which buildings are not accounted for in the design. Theseimpact forces produce high-amplitude, short-duration local accelerationswhich could induce severe structural and non-structural damage in thebuildings. Some evidences of such damages were observed in manyearthquakes as shown in Figure (1.1). This figure presents one of thecommon pounding damage, which occurred due to the large difference inthe dynamic properties, and in the heights of closely adjacent buildings.Another type of pounding damage is shown in Figure (1.2) which occurredat mid-height of columns when floors of closely adjacent buildings havedifferent levelsAlthough, some modern codes such as Uniform Building Code(UDC-88), National Building Code of Canada (NBCC-1990) and theEgyptian Code for Loads (ECL-93) may include seismic separationrequirements for adjacent structures, larger sections of cities were builtbefore such requirements were introduced. Thus, in every city manybuildings will be found in contact with each other and therefore susceptibleto pounding damage. Moreover, the recent researchers indicate the need formore studies to examine and recheck the code requirements.