Pounding of adjacent buildings or parts of buildings due to earthquake shaking is often implicated as a significant source of damage. The majority of theoretical studies of pounding have focused on determination of the minimum separation required to prevent pounding. While this is useful for design of new structures, a great many existing structures are not sufficiently separated to preclude pounding. For these existing structures it is clearly useful to have a measure of the expected level of damage that may occur in future earthquakes. This paper attempts to assess the effects of pounding from measured earthquake records. The concept of Maximum Impact Velocity Spectrum (MIV) is introduced. The MIV records the envelope of the maximum impact velocity obtained during the earthquake for all separation distances as a function of the structure's natural period. Several measured earthquake records are considered and some surprising results are obtained.
