Pounding among adjacent MRF multi-story buildings with open first storey and different floor heights

The primary objective of this paper is to assess the response of neighboring colliding buildings with insufficient separation distances. Infill masonry panels significantly influence the overall behavior and seismic response of (MRFs), particularly in the common scenario of a soft first story. A numerical simulation was conducted on a 12-story (RC) frame, along with one-story and 6-story buildings. Dynamic nonlinear time-history analyses, using ground motion records were performed to evaluate the seismic response . The study focuses on the seismic interaction among adjacent buildings of varying heights and different story levels, including a soft story at the first floor (pilotis). Two pounding scenarios were examined in all interacting buildings: Case A (slab-to-slab) and Case B (slab-to-column). Two configurations were considered: a fully infilled 12-story frame and an infilled 12-story frame with a soft first floor. Additionally, two directions of excitation (positive and negative) were analyzed, as they significantly influence the buildings’ responses due to the asymmetry of the adjacent building pairs. Structural response parameters include story displacement, inter-storey drift, induced pounding force, hysteresis loops, and the performance level of plastic hinges in the ground columns. The results indicate that the pilotis arrangement significantly amplifies the first inter-storey drift . Case B pounding has a more pronounced effect on the adjacent buildings’ responses and causes greater permanent deformation compared to Case A pounding. The seismic pounding depends on the properties of each building, the characteristics of the input excitation, the configuration of infill panels, and the direction of the input excitation.