Structural flexibility impact on pounding severity and seismic performance of adjacent isolated buildings

Limited research on the pounding of adjacent isolated buildings (floor-to-floor pounding) and conflicting results about the effect of ductility on pounding severity highlight the need for further investigation. Therefore, this study aims to investigate the impact of superstructure flexibility and isolator characteristics on pounding severity and seismic performance of adjacent isolated buildings. To achieve this, several 3D models were designed, and the effects of flexibility variations were examined in four scenarios under pounding. These scenarios involved changing response modification coefficient (Ri), building height, superstructure system type, and isolator period (Tb). Due to the time-consuming nature of nonlinear dynamic analysis, the endurance time (ET) method was employed to assess the seismic response. Results indicate that increasing isolator flexibility and decreasing superstructure flexibility led to a reduction in the performance of isolated buildings under pounding. However, these factors were found to have an insignificant impact on the performance of taller adjacent isolated buildings. Furthermore, the critical point for adjacent isolated buildings in most scenarios was found to be the isolated level.