Adjacent buildings, especially in unplanned localities, usually have insufficient seismic gap between them with unequal floor levels. It is evident from the post-earthquake reconnaissance studies, such as Mexico city earthquake (1985), Nepal earthquake (2015), etc., that the buildings adjacent to each other experience damage due to pounding during strong earthquakes. Often the adjacent buildings are of different floor heights due to architectural or site requirements. Thus, it is important to study the effect of unequal slab levels, in adjacent buildings, on the seismic pounding. In this study, two adjacent reinforced concrete (RC) frames, 2-story and 4-story with three different slab levels are considered. Finite element modelling of these RC frames is done in ABAQUSv2021 [Abaqus 2011]. Non-linear elastic contact is modelled in between the considered frames. Three different ground motion records are considered to perform non-linear time history analyses. The seismic responses, such as peak interstory drift ratio, peak floor acceleration, pounding force, total energy dissipation, and damage index are studied. It is observed that the responses, such as peak interstory drift and peak pounding force are critical in the frames with unequal floor levels in comparison to those with equal floor levels. Hence, it is concluded that drift-sensitive non-structural building components would be subjected to maximum damage in stiffer buildings with equal slab level interaction whereas in flexible building with two-third slab level interaction. At the same time, peak pounding force is maximum in adjacent buildings with slabs at two-third levels.

Adjacent Buildings; Drift-Sensitive Non-Structural Components; Pounding; Pounding Force; Seismic Gap; Seismic Pounding; Unequal Floor Levels.